UNIT 1
Structure
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
Introduction
Objectives
Plant biodiversity
1.3.1 Plant biodiversity : concept
1.3.2 Types of biodiversity
1.3.3 Biodiversity at global levels
1.3.4 Status in India
1.3.5 Utilization of plant biodiversity
Sustainable development
1.4.1 Basic concept
1.4.2 The elements of sustainable development
1.4.3 Different ways of viewing sustainable development
1.4.4 Importance of sustainable development
1.4.5 The need for sustainable development
1.4.6 What we can do?
Origins of agriculture
1.5.1 Ancient origin
1.5.2 Middle ages
1.5.3 Modern era
1.5.4 Ancient Indian economic botany
World centres of primary diversity of domesticated plants
1.6.1 Origin of crop plants
1.6.2 Plants domestication
1.6.3 World centres of origin of domesticated plants
1.6.4 Process of domestication of crop plants from their wild progenitors
Let us sum up
Check your progress : the key
Assignments/ Activities
References/ Further Readings
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1.1
INTRODUCTION
A Upanishadic rhymes is
“A Guru (i.e., master) asked his disciple to bring some waste plants, thereupon the
disciple goes in search of these plants and later comes only to report to his guru that
he could not find a single plant which is 'waste'.”
This means that plant on earth has some value. Nature has given plenty of plant
resources to human beings and he started tailoring them ever since the beginnings of
civilization in manifold ways to suit his needs whether knowingly or unknowingly.
The civilization of man went hand in hand with the domestication and cultivation of
crop plants and their evolution took place according to the evolution of mind and
thought. Millions of years, the evolution of crop plants has been taking place with the
direct human agency either consciously or unconsciously.
The quest for more knowledge of plant resources continues concomitant with the rise
in population and depletion of food materials. Many new plants have been added to
the existing ones with the modern techniques and trends in human utilization.
Plants bring about economy to the country at large and it is a fact that the wealth of
any country largely depends upon its agriculture and plant products.
In this unit, we shall review all aspect of plant diversity, sustainable development, and
origin of plants and their domestication.
1.2
OBJECTIVES
The main objectives of this unit are to know the plant wealth present on the earth,
sustainable use of its components and their conservation. The major objectives of
present study are :

To understand the plant biodiversity and its component;

To study the sustainable development and identify the sustainable use of natural
resources;

To understand origin of agriculture and primary centres of domesticated plants;

To explain the process of domestication of crop plants.
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1.3
PLANT BIODIVERSITY
1.3.1 Concept and definition
Planet Earth is endowed with a rich variety of life forms and the teeming millions of
these living organisms have been well-knit by the laws of nature. The interdependence of the various life forms starting from the unicellular primary producers
to the complexly built higher plants and animals is a unique feature of this green
planet.
Bio-diversity, as this assemblage of life forms is referred to, has now been
acknowledged as the foundation for sustainable livelihood, and food security.
Scientists have estimated that more than 50 million species of plants and animals
including invertebrates and micro-organisms occur on earth and hardly 2 million of
them have been described by man so far. Scientists are also aware of the immense
potentials of the various life forms especially in the context of recent advances made
in science and technology. The incessant human assault on forests has left indelible
scars on nature. One result of the United Nations Conference on Environment and
Development held in Rio de Janerio in June 1992 was a “Convention on Biological
Diversity” which was signed by 156 countries and European community.
Definition
Biological diversity refers to the variety and variability among living organisms and
the ecological complexes in which they occur. Diversity can be defined as the number
of different items and their relative frequency. For biological diversity, these items are
organized at many levels ranging from complete ecosystems to the chemical
structures that are the molecules basis of heredity. Thus the term encompasses
different ecosystems, species, genes and their relative abundance.
1.3.2 Types of Biodiversity
The term biodiversity includes three different aspects, which are closely related to
each other. Following are the types of biodiversity:
Genetic Diversity
It refers to the variation of genes within the species. This constitutes distinct
population of the same species or genetic variation within population or varieties
within a species.
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Species diversity
It refers to the variety of species within a region. Such diversity could be measured on
the basis of number of species in a region.
Ecosystem Diversity
In an ecosystem, there may exist different landforms, each of which supports different
and specific vegetation. Ecosystem diversity is difficult to measure since the
boundaries of the communities, which constitute the various sub ecosystems, are
elusive.
Ecosystem diversity could best be understood if one studies the communities in
various ecological niches within the given ecosystem; each community is associated
with definite species complexes. These complexes are related to composition and
structure of biodiversity.
Agro-Biodiversity
The agricultural biological diversity more commonly referred to as the agrobiodiversity has been fast emerging as a strong, evolutionary divergent line from the
biodiversity, which deals with the life forms at large. It has been specifically
recognized to differentiate between concern for ecosystems versus agro-ecosystems,
wild forest flora and fauna versus agriculture related plants, reptiles, insects, avian
and microbes; in situ conservation of wild forms versus on farm conservation of
landgraves and traditional/ primitive cultivars or ex-situ conservation of plant genetic
resources, etc.
Agro-biodiversity in a traditional farming system is as follows (adopted from Altieri,
1991 and UNDP, 1995):

Rich in plant and animal species

A wide diversity of niches in the local environment utilized

Reuse of organic residues, consuming biomass enabled

Ecosystem functions, such as pest, weed and disease management enhanced

Locally available resources consumed to an advantage

Reduction of risk and optimization of resources use

Associated with farmers time tested local knowledge about resources.
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1.3.3 Biodiversity at Global Levels
It is estimated that there exists 5-30 million species of living forms on our earth and of
these, only 1.5 million have been identified and include 3,00,000 species of green
plants and fungi, 8,00,000 species of insects, 40,000 species of vertebrates and
3,60,000 species of micro-organisms.
Recently it has been estimated that the number of insects alone may be as high as 10
million, but many believe it to be around 5 million.
The tropical forests are regarded as the riches in biodiversity. According to the
opinion of the scientists more than half of the species on the earth live in moist
tropical forests, which is only 7% of the total land surface. Insects (80%) and primates
(90%) make up most of the species.
Table 1.1 : Estimated number of species worldwide
Taxonomic Group
Number of Species
Bacteria
3600
Blue Green Algae
1700
Fungi
46983
Bryophytes
17000
Gymnosperms
Angiosperms
750
250000
1.3.4 Status in India
During the last few years, the subject of conservation of biological diversity has
attracted considerable attention at the national and global levels. India is a rich centre
of biodiversity and has contributed many economic plants to the world and many
useful genes for genetic upgrading of cultivated plants and domesticated animals.
India has a land mass of 329 million hactares with a diversified eco-geographical
regions. Almost all types of habitats available in the world are found in India. Ther
are two biogeographical realms in India and it is the confluence of floras and faunas
of Africa, Mediterranean, European, Sino-Japanese and Malayan rgions. As a result,
we have a rich biological diversity (Gadgil, 1992).
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Plant Species diversity
At present 1.7 million species have been recorded so far in the world (Global
Biodiversity, 1995). India’s contribution to this record stands at 7 %. Surveys
conducted so far have inventorised over 47,000 species of plants and over 89,000
species of animals. Survey and inventorisation of India’s biodiversity is still far from
complete especially the lower groups of plants and invertibrate animals (Table 1.2).
Table 1.2 : India’s Biological Wealth
Plant Taxa
Bacteria
Viruses
Algae
Species
850
Unknown
6500
Animal Taxa
Protista
Mollusca
Arthropoda
(Insecta, Crustacea etc.)
Other Invertebrates
Protochordata
Pisces
Fungi
Lichens
Bryophytes
14500
2000
2850
Pteridophytes
Gymnosperms
Angiosperms
1100
64
17500
Amphibian
Reptilian
Aves
Mammalian
Total
45364
Total
Species
2577
5070
68389
8329
119
2546
209
456
1232
390
89317
Based on the available data, India ranks 10th in the world and 4th in Asia in plant
diversity and ranks 11th in the number of Angiosperm species (table 1.3). India ranks
10th in the number of mammalian species and 11th in the number of endemic species
of higher vertebrates in the world.
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Table 1.3 : Number of angiosperm species in different countries.
Country
Angiospermic species
Brazil
55000
Colombia
45000
Ecuador
29000
China
27000
Mexico
25000
Australia
23000
South Africa
21000
Indonesia
20000
Venezuela
20000
Peru
20000
India
17000
Floristic status
As noted earlier 47,000 species of plants representing about 12 % of the recorded
world’s flora have already been identified. Comparative statement of recorded
number of plant species in India and the world is given in Table 1.4.
Table 1.4 : Comparative statement of Recorded number of
plant species in India.
Plant Taxa
Species
Percentage of India
to the World
India
World
Bacteria
850
4000
21.25
Viruses
Unknown
4000
-
Algae
6500
40000
16.25
Fungi
14500
72000
20.14
Lichens
2000
17000
11.80
Bryophytes
2850
16000
17.80
Pteridophytes
1100
13000
8.64
64
750
8.53
17500
25000
7.00
Gymnosperms
Angiosperms
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Flowering plants accounts nearly 17,500 among 45,000 species of plants. The
important economic species includes rice, sugar cane, coix, beans, cowpeas, banana,
Citrus, mango, coconut, cardamoms, nutmeg, tea, cotton, jute, colocasia, pepper,
ginger, Rhododendron, Jasmines, bamboos, Orchids, betel leaf etc.
Two regions of our country harbours maximum diversity, they are North-East and
Sourth-West India. The North- East region is a very active centre of evolution and has
diversity for a number of plants like Rhododndron, Camelia, Magnolia, Buddleia, etc.
(Khosoo, 1991).
On the basis of distribution pattern of plants, Good (1953), divided plant wealth into
37 floristic zones. With in these zones, pockets of diversity of plants species arose and
they were domesticated by human kind during the past 10,000 years.
During these years enormous variability was genertated because of mutation,
recombination and selection process. The result being complex variation pattern in
plants. These evolved plants bear little or no resemblance with their ancestorsss.
Endemic Species
Every major habitat, from areas of heavy rainfall to the dry desert, from coldest to the
hottest climatic conditions, from highest elevation down to the sea level is found in
the country. India has a rich endemic flora.
Endemism of Indian biodiversity is significant. About 4950 species of flowering
plants or 33% of this recorded flora are endemic to the country. These are distributed
over 141 genera belonging to 47 families. These are concentrated in the floristically
rich areas of North-East India, the Western Ghats, North-West Himalayas and the
Andaman & Nicobar Islands.
The Western Ghats and Eastern Himalayas are reported to have 16000 and 3500
endemic species of flowering plants, respectively. These areas constitute two of the 34
hot spots identified in the world.
Cultivated plants
Indian region alone has given to the world nearly 167 economical plants whose centre
of origin/ diversity lie in India along with their 320 species of wild relatives and land
races.
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India is considered to be the centre of origin of rice, sugar cane, minor millets, pigeon
pea, brassicas, rice-bean, Asiatic vignas, egg plant, banana, citrus, mango, cardamom,
jack fruit, jute, edible diascorea, black pepper, seed amaranths, turmeric, ginger,
several umbellifers and cucurbits, bittergourd, colacasia, okra, coconut, bamboo, taro,
indigo, sun hemp, gooseberries and many herbal drugs, rhododendron, jasmine, some
orchids and betel nut. This remarkable diversity of life-forms in a single country is
because of the great diversity of ecosystems.
The gene bank of National Bureau of Plant Genetic Resources (NBPGR) has a
collection of over 1,59,080 varieties. The details of the active germplasm holding and
base collections of NBPGR are given in Table 1.5.
Table 1.5 : Active germplasm holding and base collections at NBPGR.
Crop groups
Cereals
Pulses
Millets & Minor Millets
Oilseeds
Vegetables
Medicinal & Aromatic Plants
Pseudocereals
Tuber Crop/ Spices
Forage Crop
Horticultural/ Ornamentals
Fibre Crops
Released crop Varieties
Reference Samples
(Medium Term)
Total
Active
germplasm
Base collection
holdings
12086
38695
10349
19808
12146
870
4739
2053
4060
22212
-
43409
22269
14488
14278
5681
942
736
3212
904
53161
107018
159080
Wild relatives of Crops
There are several hundred species of wild crop relatives distributed all over the
country. A major centre for wild rice is the eastern peninsular India, i.e., West Bengal,
Orissa and Andhra Pradesh. The North-Eastern hills and Tamil Nadu hills are rich in
wild relatives of millets. Wild relatives of wheat and barley have been located in the
western and North-Eastern Himalaya. Table 1.6 gives the statement of wild relatives
of crops recorded so far.
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Table 1.6 : Wild relatives of crop
Crop
No. of
Wild relatives
Millets
Fruits
Spices and condiments
Vegetables and pulses
51
104
27
55
Fibre crop
Oil seeds, tea, coffee,
tobacco, & sugarcane
Medicinal plants
24
12
3000
1.3.5 Utilization of plant biodiversity
Biological resources contribute much to the social and economical development of the
nation. Utilizing the species for industry and medicine and developing new products
for national and international market provides good opportunities. Greater agricultural
production and prevention of diseases and pests are also important. Biological and
genetic diversity are fundamental to the proper functioning of any ecosystem and
hence to human welfare.
The most important contribution of the earth’s biota is to maintain the ecosystem
ability to provide essential life support functions, e.g. fixation of solar energy. Genetic
resources are most precious asset. They are nature’s tool for harvesting solar energy
and processing mineral resources in to food, fibre, fertilizer etc. They are crucial for
human survival in the physical environment. They are the result of evolution over
million of years.
Biological resources are active entities and extremely vulnerable. Once they are lost,
they can not be replaced at any cost.
Success of genetic engineering depends upon genes (the basic building blocks) from
plants, animals and micro-organisms. Therefore, ensuring success in genetic
engineering, we need to conserve biological resources.
Genetic diversity is heritable with in and between of the species of a genus. Genetic
diversity is very critical to our agriculture, horticulture, forestry and animal
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husbandry. Many germplasms from India have made many distinctive contributions in
plant improvement. Broadly speaking biological diversity satisfies human needs in
two different ways, direct and indirect.
Biodiversity will not only help in increasing agricultural productivity but also in
developing disease resistant varieties. It was evident in the early 1970’s when
epidemic called grassy stunt virus destroyed more than 1,60,000 ha of rice in Asia,
could be controlled from a single sample of wild rice Oryza nivara from Central
India, which was found to be the only known genetic source of resistance to the
grassy stunt. Besides 20 major genes from wild for disease and pest resistance are
used in rice improvement programmes.
Besides food and other basic needs, human health has gained priority in welfare
programmes. Once all medicines used to come from plant and animal resources.
Worldwide medicines from plants are now worth 40 billion dollars a years. Even now
80 percent people in the developing countries depend upon traditional medicines.
Indirect benefits include nutrient trapping, maintaining water cycles, soil production
and protection of soil, absorption and break down of pollutants, provision of
recreational, aesthetic, scientific, spiritual etc.
It is estimated that more than 25 percent of all medicines available today are derived
from tropical plants. Over 40 percent of Pharmaceuticals available in the USA depend
on natural sources.
In 1960, a child contracting Leukemia had one chance in five survival, since then
scientists have developed a drug – Vincristine from a plant of the tropical forests,
Vinca rosea, that now allow leukemia sufferer four chances in five of survival.
The National Cancer Institute near Washington DC has screened 29,000 plant species,
and at least five may come to rival vincristine. The institute believes that mass
extinctions of species could represent a serious back to the future of anti-cancer
campaigns.
Among other medical products the “pill” that is swallowed by million women each
day contains sex hormone combination derive from a Mexican forest yam. Over-thecounter sales of the pill are re worth one million dollar a year.
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Prioritization approach and patenting
The list of species to be conserved is ever-increasing. There are also other plants and
animals, which are likely to be important in future. There is a whole range of
threatened/ endangered plants numbering around 2000 in India. Resource constraints
do not allow, all these to be saved and it would be totally unrealistic even to attempt
this.
Approach of prioritization, both of economic importance and academic interest are
needed. With in a country different states could select an indigenous mammal, bird,
wild flower and a tree. These could then be declared as state mammal, bird, flower
and tree. Rajasthan state has declared Great Indian Bustard (Ardeotis nigriceps) as
state bird and Khejri (Prosopis cineraria) as state tree. Based on indepth study, an
agreed list of species could be arrived and the best way of conservation method(s) to b
employed.
Patents are meant to stimulate innovation and increase public perception about new
ideas and inventions. A patent is, therefore, a limited monopoly for a given number of
years during which patentee has exclusive rights to the invention. In view of
expanding role of “Genetic raw materials” is genetic engineering, patenting of
cultivars by multinationals has to be looked in a proper manner. During patenting,
legal, economical and technical issues may be taken into account.
Each country needs to critically review their network of conservation areas, together
with their future plans. The conservation of just wild animals alone will not succeed
unless, the carefully chosen ecosystem need to be taken up for conservation purpose.
Special attention must be paid to forests having large biological diversity of plants
and animals.
Biological diversity has become a sensitive subject. Countries having biodiversity
needs to adopt a code of conduct and has to conserve the diversity for sustainable use
for the future generations.
National network for the management of protected areas with clearly specified interconnections are required. There is a need for long range, land use planning of the
protected areas. The management plan must be science and technology based and it
should to be over-exploitation. To accomplish such an obligation necessary legislative
and scientific steps should be taken for the survival, regulation and conservation of
threatened species.
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1.4
SUSTAINABLE DEVELOPMENT
1.4.1 Sustainable Development : Basic Concept
Sustainable development focuses on improving the quality of life for all the Earth’s
citizens without increasing the use of natural resources beyond the capacity of the
environment to supply them indefinitely. The sustainable development concept begins
with an understanding that inaction has consequences and that we must find
innovative ways to change institutional structures and influence individual behaviour.
There is growing understanding of the interconnection between global ecological,
economic and political/ social systems and it has become important to consider
economic prosperity in an integrated way with social development and environmental
protection. Traditional decision-making, which focused primarily on social and/ or
economic considerations, with environmental issues usually neglected unless the
policy issue specifically pertained to the environment, has been replaced with an
integrated decision-making approach, in which environmental issues must be
considered along with the social and economic ones.
Sustainable Development is about taking action and changing policy and practice at
all levels, from the individual to the international. To make sustainable development a
reality, there must be cooperation and change from governments, businesses and
communities around the world.
The information contained in this component will provide you an overview of
sustainable development and help you to learn:

What sustainable development is and why it’s important;

About different ways of viewing sustainable development;
16

To embrace sustainable development approaches; and,

What you can do to live a ‘greener’ life.
The Brundtland Report
The most commonly used definition today comes from “Our Common Future,” more
commonly known as the Brundtland Report, the result of the work done by the World
Commission on Environment and Development:
“Sustainable development is development that meets the needs of the present without
compromising the ability of future generations to meet their own needs.”
The ultimate goal of SD is the advancement of life within the carrying capacity of the
environment and at no expense to future generations. It is based on the logic that as a
society works toward progress, its initiatives are more likely to be sustainable if they
are based on integrated decision making that acknowledges the interdependent
linkages between economic growth, social development and environmental
protection. It assesses not only the immediate but the long-term impacts of one on the
other, seeks resolution of conflicting views, mitigates any negative impacts, and,
ultimately, indicates the best way forward for a sustained result.
Sustainable in this context means to maintain the necessary and desired
characteristics of people, their communities and their surrounding environment for
the long term (indefinitely).
Development in this context means to bring something to a fuller and better
condition. It is a qualitative idea that should be distinguished from growth, which is
purely a quantitative physical increase. The combination of these two concepts
“sustainable” and “development” embody the world need to preserve and improve
certain areas in order for life (people, plants and animals) to endure.
An Evolving Concept
Sustainable development is a generally accepted concept applicable in all walks of
life, but it is not a static concept. It is an ongoing process that requires constant reevaluation of current and future needs, and requires a careful assessment of the
strengths of every household, community, or organization to determine priority
actions.
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Goals may well need to be refined over time in light of new information and events.
However, setting provisional targets allows us to develop strategies to avoid critical
risks and keep options open for the future.
1.4.2 The Elements of Sustainable Development
The main elements of sustainable development emerged at the 1972 United Nations
Conference on the Human Environment in Stockholm, Sweden. More than a decade
later, the World Commission on Environment and Development (the Brundtland
Commission, 1987) built on earlier work by encouraging sustainable development in
three inter-related areas:
Equity
A commitment to equity involves the fair distribution of the costs and benefits of
development between the rich and the poor, between generations, and among nations.
Equity also implies that we all have the means to meet basic needs, and that we are all
entitled to basic rights. Sustainable development acknowledges that if we ignore our
effects on others in an interdependent world, we do so at our own peril.
Integrated Decision-making
Sustainable development essentially asks us to undertake a new paradigm of decisionmaking. It challenges us to view the issues facing us through a more holistic and
forward-looking lens. Traditional decision-making focused primarily on social and/or
economic considerations, with environmental issues usually neglected unless the
policy issue specifically pertained to the environment.
Now, environmental issues must be considered along with the social and economic
ones. Integrated decision-making of this nature is important at both the strategic
(policy) level, and at the level of project implementation.
Quality of Life
Quality of life is important to all peoples. Like Canadians, others want an economy
that performs well. A healthy economy meets demands for job creation, economic
security and improved living standards. It also allows countries to pursue the social
objectives that are key elements of their quality of life – including health, education,
safety and security systems – now and for future generations.
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1.4.3 Different Ways of Viewing Sustainable Development
Visual Metaphors
Sustainable development is a multifaceted concept that can be difficult to
communicate to others. People who work in this field often use visual metaphors as a
way of representing and communicating these complexities.
The four visual metaphors introduced in this section represent different ways of
“seeing” sustainable development. No single metaphor is better than another; each has
its place in helping us to understand sustainable development in all its complexity.
The Mobile
The mobile is a useful metaphor when trying to explain the interdependency of
sustainable development activities. Each lobe on the mobile represents an aspect of
human development.
When changes are made in one area, the equilibrium of the entire mobile is affected –
for the better it is hoped. The entire structure remains in motion until a new
equilibrium is found.
The mobile metaphor is a useful reminder that the full range of possible consequences
should be considered carefully before implementing a development initiative.
Lenses in a Sphere
The Lenses in a Sphere metaphor helps to capture the idea that the perspective you
begin with colours your impression of the problem, possible solutions, and likely
outcomes.
For instance, looking at sustainable development through an environment lens is
likely to highlight environmental needs and suggest environmental approaches –
perhaps to the exclusion of other possibilities. That would also be true if you looked
through the political lens, or social development lens.
The implication is that every need should be viewed through as many lenses as
possible in order to understand the need in all its dimensions and to fashion an
integrated response.
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The Egg of Sustainability
In the “egg of sustainability”, humanity is represented as the yolk and the ecosystem
as the egg white. Together, they represent a complete, but fragile entity.
This metaphor is used to communicate the idea that people are an integral part of an
ecosystem and that the well-being of both people and the ecosystem need to be
improved together. Only when both the human and the ecosystem conditions are good
or improving do you have a sustainable society.
A System in Balance
The Systems Perspective of sustainable development is borrowed from systems
engineering, which solves multifaceted problems by applying knowledge from a
variety of disciplines in effective combinations.
The systems perspective recognizes that there are a number of distinct circles of
sustainable development activity, each with its own theories, priorities, and activities.
However, when addressing complex human development needs, it is rare to find one
of these needs in isolation. It is helpful to think of the circles overlapping – sometimes
to a greater extent, other times to a lesser extent. In the places where one or more of
the circles overlap, you find hybrid approaches that draw from the strengths of each
intersecting discipline.
1.4.4 Importance of Sustainable Development
The Sustainable Development Imperative
As the interconnectedness of our lives is made more apparent, the need for a modus
operandi that assesses, as much as possible, the short and long-term impacts of any
action and mitigates the negative factors, seems apparent. Sustainable development is
such a modus operandi.
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
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






]

Thinning Ozone Layer
Emissions in the North have thinned the protective ozone layer over Antarctica,
increasing the rates of skin cancer in the south..
Financial Crises
Financial Crises in Asia have threatened the economies of other countries around the
world.
Ethnic Violence
Ethnic violence in Central Africa has led to refugee migrations that are overwhelming
the support systems of nearby regions.
Deforestation
At the current rate of deforestation, the Amazon Forest could cease to exist within one
hundred or two hundred years.
Desertification
Africa and many other parts of the world are affected by desertification, the loss of
vegetation, organisms, and the expansion of degraded soil, leading to severe food
shortages.
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Threatened Marine Biodiversity
All around the world, much of the world’s marine biodiversity face threats from
activities and events such as coastal development, over-fishing, inland pollution and
global climate change.
Radioactive Contaminates
Radioactive contamination, a result of the nuclear industry’s careless past, has
damaged several regions in Russia. Lake Karachay is now considered to be one of the
most polluted spots on Earth.
Environmental Impact of Fast-food Restaurant Chains
The proliferation of fast-food restaurants in North America is having a major
environmental impact. Intensive breeding of livestock and poultry for these
restaurants leads to deforestation, land degradation, and contamination of water
sources and other natural resources.
Air Pollution
The prevalence of heavy industry, the intensive use of low quality fossil fuels,
substantial lack of modern production and environmental technologies, as well as a
recent rapid growth in the number of passenger cars is causing air quality problems to
be the top environmental priority in Europe.
1.4.5 The Need for Sustainable Development
Ultimately, SD considerations incorporated into policies, work plans and actions will
help address pressing sustainable development needs around the world in the
knowledge that without a decent quality of life, supported by sustained broad-based
economic growth, people cannot maintain environmental protection measures.
1.4.6 What can we do?
Time is running out. We are already faced with full-scale emergencies through
‘freshwater shortages, tropical forest destruction, species extinction, urban air
pollution, and climate change.’ You could help to increase environmental awareness
and motivate the people to live a ‘greener’ life by pursue these steps :
22
1.
Use Energy Efficiently : Energy is essential to our way of life, yet energy
production and consumption have significant environmental implications.
Energy conservation can help reduce health and environmental impacts.
2.
Use Green Driving : Change your driving habits by avoiding unnecessary idling
when driving, car pooling with friends and co-workers, and walking, cycling or
using public transit wherever possible.
3.
Reduce use of Ozone Depleting Substances (ODSs) : The ozone layer is a
concentration of ozone molecules in the earth’s stratosphere that filters the sun’s
ultraviolet (UV) radiation. Some ODSs occur naturally in the environment (for
example, chlorine from volcanoes); however, most are man-made and more
damaging than those that occur naturally. Some common sources of ODSs are
refrigerants (chlorofluorocarbons), solvents for cleaning foam blowing agents,
aerosol solvents and propellants, fire extinguishers, and pesticides.
1.5
4.
Manage solid waste in order to reduce health and environmental impacts.
5.
Use Water Wisely.
6.
Assist in educating and training colleagues in your organization.
ORIGINS OF AGRICULTURE
A brief outline of the origins or the beginnings of
agriculture, the starting point of all economic
botany, in the form of crop plants and their
domestication will help to understand the scope of
the subject in greater detail.
A Sumerian harvester's sickle made
from baked clay (ca. 3000 BC).
Man has originated on earth some two million years ago of which the present day
civilized man dates back only to an infinitely small fraction of time as some 10,000
years back and the rest of the time he has been a hunter-gatherer. Later, man learned
out of necessity, obviously, to cultivate certain plants and food production became
more efficient with the origins of agriculture; civilization of man went hand in hand
with new techniques of cultivation and bringing more plants into cultivation.
23
Since its development roughly 10,000 years ago, agriculture has expanded vastly in
geographical coverage and yields. Throughout this expansion, new technologies and
new crops were integrated. Agricultural practices such as irrigation, crop rotation,
fertilizers, and pesticides were developed long ago, but have made great strides in the
past century. The history of agriculture has played a major role in human history, as
agricultural progress has been a crucial factor in worldwide socio-economic change.
Wealth-concentration and militaristic specializations rarely seen in hunter-gatherer
cultures are commonplace in societies which practice agriculture. So, too, are arts
such as epic literature and monumental architecture, as well as codified legal systems.
When farmers became capable of producing food beyond the needs of their own
families, others in their society were freed to devote themselves to projects other than
food acquisition. Historians and anthropologists have long argued that the
development of agriculture made civilization possible.
Check your progress 1
Notes :
a). Write your answer in the space given below.
b). compare your answer with those given at the end of the unit
Que.
1. What can you do to conserve energy?
2. What can you do to manage solid waste in order to reduce health and
environmental application?
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1.5.1 Ancient Origins
24
An ancient Egyptian farmer
The Fertile Crescent of the Middle East, Egypt, and India were sites of the earliest
planned sowing and harvesting of plants that had previously been gathered in the
wild. Independent development of agriculture occurred in northern and southern
China, Africa's Sahel, New Guinea and several regions of the Americas. The eight socalled Neolithic founder crops of agriculture appear: first emmer wheat and einkorn
wheat, then hulled barley, peas, lentils, bitter vetch, chick peas and flax.
By 7000 BC, small-scale agriculture reached Egypt. From at least 7000 BC the Indian
subcontinent saw farming of wheat and barley, as attested by archaeological
excavation at Mehrgarh in Balochistan. By 6000 BC, mid-scale farming was
entrenched on the banks of the Nile. About this time, agriculture was developed
independently in the Far East, with rice, rather than wheat, as the primary crop.
Chinese and Indonesian farmers went on to domesticate taro and beans including
mung, soy and azuki. To complement these new sources of carbohydrates, highly
organized net fishing of rivers, lakes and ocean shores in these areas brought in great
volumes of essential protein. Collectively, these new methods of farming and fishing
inaugurated a human population boom dwarfing all previous expansions, and is one
that continues today.
By 5000 BC, the Sumerians had developed core agricultural techniques including
large scale intensive cultivation of land, mono-cropping, organized irrigation, and use
of a specialized labour force, particularly along the waterway now known as the Shatt
al-Arab, from its Persian Gulf delta to the confluence of the Tigris and Euphrates.
Domestication of wild aurochs and mouflon into cattle and sheep, respectively,
ushered in the large-scale use of animals for food/fiber and as beasts of burden. The
shepherd joined the farmer as an essential provider for sedentary and semi-nomadic
societies. Maize, manioc, and arrowroot were first domesticated in the Americas as
far back as 5200 BC. The potato, tomato, pepper, squash, several varieties of bean,
tobacco, and several other plants were also developed in the New World, as was
25
extensive terracing of steep hillsides in much of Andean South America. The Greeks
and Romans built on techniques pioneered by the Sumerians but made few
fundamentally new advances. Southern Greeks struggled with very poor soils, yet
managed to become a dominant society for years. The Romans were noted for an
emphasis on the cultivation of crops for trade.
1.5.2 Middle Ages
A water-raising machine
invented by Al-Jazari (1136-1206),
an Arab inventor and engineer.
During the Middle Ages, Muslim farmers in North Africa and the Near East
developed and disseminated agricultural technologies including irrigation systems
based on hydraulic and hydrostatic principles, the use of machines such as norias, and
the use of water raising machines, dams, and reservoirs. They also wrote locationspecific farming manuals, and were instrumental in the wider adoption of crops
including sugar cane, rice, citrus fruit, apricots, cotton, artichokes, aubergines, and
saffron. Muslims also brought lemons, oranges, cotton, almonds, figs and sub-tropical
crops such as bananas to Spain. The invention of a three field system of crop rotation
during the middle ages, and the importation of the Chinese-invented moldboard plow,
vastly improved agricultural efficiency.
1.5.3 Modern Era
After 1492, a global exchange of previously local crops and livestock breeds
occurred. Key crops involved in this exchange included the tomato, maize, potato,
cocoa and tobacco going from the New World to the Old, and several varieties of
wheat, spices, coffee, and sugar cane going from the Old World to the New.
The most important animal exportation from the Old World to the New was those of
the horse and dog (dogs were already present in the pre-Columbian Americas but not
in the numbers and breeds suited to farm work). Although not usually food animals,
the horse (including donkeys and ponies) and dog quickly filled essential production
roles on western hemisphere farms.
26
By the early 1800s, agricultural techniques, implements, seed stocks and cultivated
plants selected and given a unique name because of its decorative or useful
characteristics had so improved that yield per land unit was many times that seen in
the Middle Ages. With the rapid rise of mechanization in the late 19th and 20th
centuries, particularly in the form of the tractor, farming tasks could be done with a
speed and on a scale previously impossible. These advances have led to efficiencies
enabling certain modern farms in the United States, Argentina, Israel, Germany, and a
few other nations to output volumes of high quality produce per land unit at what may
be the practical limit.
The Haber-Bosch method for synthesizing ammonium nitrate represented a major
breakthrough and allowed crop yields to overcome previous constraints. In the past
century agriculture has been characterized by enhanced productivity, the substitution
of labor for synthetic fertilizers and pesticides, selective breeding, mechanization,
water pollution, and farm subsidies. In recent years there has been a backlash against
the external environmental effects of conventional agriculture, resulting in the organic
movement.
Agricultural exploration expeditions, since the late nineteenth century, have been
mounted to find new species and new agricultural practices in different areas of the
world. Two early examples of expeditions include Frank N. Meyer's fruit and nut
collecting trip to China and Japan from 1916-1918 and the Dorsett-Morse Oriental
Agricultural Exploration Expedition to China, Japan, and Korea from 1929-1931 to
collect soybean germplasm to support the rise in soybean agriculture in the United
States.
In 2005, the agricultural output of China was the largest in the world, accounting for
almost one-sixth world share followed by the EU, India and the USA, according to the
International Monetary Fund. Economists measure the total factor productivity of
agriculture and by this measure agriculture in the United States is roughly 2.6 times
more productive than it was in 1948.
1.5.4 Ancient Indian Economic Botany
From the earliest time, rice, wheat and millets have been the staple food of the vast
population of India, as indicated by the presence of charred grains in most of the
excavation sites (Plate 1.1). In addition to these, references are abundant in ancient
literature about the existence and usage of several other crops of economic importance
27
such as sugarcane, barley, mango, jute, ginger, turmeric, pumpkin, gourd, cucumber,
pepper, turnip, sesamum, mustard, cabbage, potato, radish, peas, pulses etc. In ancient
time India had innumerable varieties of various crops under cultivation. About 5,000
forms of rice have been collected in the Indian Museum. Historians and archeologists
have' accumulated lot of evidence as revealed by sculptures found on ancient temples
etc.
Atharva Veda (1500-500 B.C.), Kautilya's Arthasastra (321-186B.C.), Charaka
Samhita (100-500 A.D.), Susrata Samhita (200-500 A.D.), Vishnu Purana (500 A.D.),
Agnipurana (500- 700 A,D.), Vishnudharmottara Mahapurana (500-700 A.D.) etc.
contain wealth of information regarding ancient Indian agriculture.
Apastamba Smrti (200 B.C.-200 A.D.) dealt with Hindu laws relating to agriculture.
The Buddhist literature (500 B.C. to 500 A.D.) gave various references about Blight
and Mildew; farming operations; shape of rice fields and veterinary practices.
Bruhat Samhita of Varaha Mihira (about 500A.D) is a reputed work on agriculture.
The book gave details about the kinds of plants and plant life; rain clouds; rainsupport days; winds; indication of yield of crops from blooming of flowers; vegetable
horoscopy; methods of ascertaining the presence of water in a dreary region.
Upavanavinoda by Sarangadhara (l120-1330 A.D.) is a systematic text on plants and
plant life and horticulture.
In addition to these, ancient Indian sculptures and monuments also contain grains and
plants. It is possible in the modern times to estimate the probable period of the origins
of the cultivated plants by man with considerable certainty by the recent techniques of
carbon dating.
Some estimates indicate that the early methods of cultivation of grains and
domestication of animals began round about 8000 B.C. in the mountainous regions of
Mesopotamia. The excavations of Tehuacan valley near Mexico city revealed several
facts of civilization of man and origins of several crop plants starting with maize
(5000 B.C.), squash, chilies, pepper, avocado and amaranth (4900-3500 B.C.).
Another important centre of early agriculture was found in Peru, South America at a
later period 3000 B.C. It is probable that agriculture arose independently in Old and
New world.
28
Many theories are in vogue regarding the origins of agriculture, the notable among
them being that of a shift in climatic conditions bring about the origins of cultivation.
This fact has been revealed from the fossil pollen studies in two lake beds in Iran by
H.E. Wright Jr. (cf. Heiser, 1973). These studies indicated such a shift in climate
around 11,000 years ago.
The knowledge of how to cultivate plants from seeds is a matter of much conjecture
and of the many possible explanations from historians, archeologists even
philosophers, poets, that this cultivations of seeds or plants must have been the result
of a magico-religious rites by humans.
The knowledge of sex in plants and the knowledge of seeds by humans may be
accidental or intentional due to many ceremonies and offerings in the form of
sacrifices and this knowledge got percolated to the process of agriculture and
domestication of plants. Man must have experimented with all possible food resources
of his environment, and by a process of elimination or preference he must have
chosen certain plants to domesticate and discard others.
1.6
WORLD CENTRES OF PRIMARY DIVERSITY OF
DOMESTICATED PLANTS
1.6.1 Origin of crop plants
The history of crops and man reveals that the evolution of man and the evolution of
crop plants went hand in hand. Man has become so utterly dependent on plants such
that the plants have 'domesticated' him (Harlan, 1975). The origins of crop plants and
their history reveal that the evolution of crop plants is a gradual and slow process
rather than sudden and rapid. As such, some cultivated plants differ very little from
their original wild relatives, while others differ enormously from their progenitors.
To know precisely about the present day crop plants there needs a thorough
understanding of what kinds of plants did man eat before today's crops were
available? What were the conditions that prompted him to domesticate the plants?
How was his life before agriculture?
To have a rough idea about these questions from the hunter man to the present day
civilized agricultural society. Lee and Devore, (1968) cf. Harlan, (1975) put it as
“cultural man has been on earth for some 2 million years, for over 99 percent of this
29
period he has lived as a hunter gatherer. Only in the last 10,000 years man has begun
to domesticate plants and animals, to use metals and to harness energy sources etc.”
Hunter man was too ignorant or unintelligent to understand the life cycles of plants
and they were intellectually insensitive and incapable of 'improvement'.
Gatherers used to collect grass seeds, legumes, roots and tubers, oilseeds, fruits and
nuts, vegetables and spices for their food, totaling about 1,400 species. The list
suggests that
(i)
many more species have been gathered from the wild than have ever been
domesticated,
(ii)
even after agriculture is fully developed, gathering wild plant foods is still a
worthwhile effort, and
(iii)
wild plant resources are of the same general kinds as domesticated plant
resources (Harlan, 1975).
GRASS SEEDS like wild rice (Zizania aquatica, Oryza barthii, Oryza
/ongistaminata, O. subu/ata, Panicum, Sporobolus, Digitaria, Avena barbata and A.
fatua, etc.
LEGUMES include Acacia spp., Canavalia, Vigna, Tephrosia, Phaseolus, Dolichos,
etc.
ROOTS AND TUBERS include Dioscorea, Allium, Ipomoea, Cyperus rotundus,
Eleocharis, Nymphaea etc.
OIL PLANTS fruits of Arecaceae, E!aeis guineensis, Cocos nucifera; Pistacia,
Aleurites, Theobroma (cocoa), Olea, Butyrospermum (Shea butter tree), Sesamum and
Lilium.
FRUITS AND NUTS Walnut (Juglans), hickory (Carya), Chestnut (Castanea), Oak
(Quercus), pine-nuts (Pinus); Vitis, Ficus, Citrus, Musa, Artocarpus, Annona and
Carica etc.
VEGETABLES AND SPICES species of wild Capsicum, Lycopersicon, Nicotiana,
Cucumis, Momordica, Luffa, Lagenaria etc.
30
Thus, the gatherers exploited a wide range of plants wherever they found them. As a
result of this practice, independent domestications of different species of the same
genus occur and if the genus is wide spread, the different domesticates originate in
different continents of the world. Some examples of such wide spread domestications
include, Amaranthus, Annona, Cucurbita, Gossypium, Phaseolus, Digitaria, Oryza,
Solanum, Dolichos, Ipomoea, Panicum etc.
From the ethaographic evidence (scientific description of races of mankind) it is
inferred that gatherers had some knowledge of planting seeds and sowed seeds of wild
plants like Chenopodium, Oryzopsis, Eleocharis etc. They also had the knowledge of
seed-bed preparation and irrigation to increase production.
Gatherers had the knowledge of how to make use of poisonous foods safe, like seeds
of Zamia (a Cycad); certain leguminous and Solanaceous fruits; Dioscorea spp.;
Aroid tubers. They also know about drugs, narcotics, medicines, fish poisons, arrow
poisons, gums, resins, glues, dyes and paints, bark cloth, woods for spears, arrows,
bows, shields, fire sticks and canoes. They had the knowledge of spinn1ng, weaving,
basket-making and construction of house hold utensils, fish traps and ceremonial
objects.
The Australian aborigins used tobacco for chewing, and another masticatory,
Duboisia hopwoodi which contains hyoscyamine, norhyoscyamine and scopolamine.
Agriculture, in mythologies of all civilizations reveal that it is a divine gift to humans
as can be seen in Egypt by Goddess Isis, Demeter in Greece and Ceres in Rome.
According to the Chinese mythology P’an Ku separated the heaven and the earth,
created the sun, moon and stars, and produced plants and animals on earth.
1.6.2 Plant domestication
According to Childe (1952, Cf. Harlan, 1975) the process of plant domestication, by
man went through a series of steps like hunter, herder and then a cultivator, the so
called Neolithic revolution i.e., a shift from hunting and gathering to food production.
The origin of domestication of plants by man seems to be that the gatherer took up,
agriculture or farming since it invo1ves more energy to obtain food by intensive
gathering and thought that cultivation is more advantageous than gathering.
1.6.3 World centres of origin of domesticated plants
31
Milestone work : Two great works, historically, by Alphonse de Candolle and N.I.
Vavilov are worth mentioning in any discussion of the origins of cultivated plants.
De Candolle was a French botanist and systematist who produced a voluminous work
called the 'Prodromus Systematis Naturalis' Regni Vegetabilis 'Origin of Cultivated
Plants (l886) concerning the geography of plants, distributions of wild relatives,
history, names, linguistic derivatives, archeology, variation patterns etc. on the
cultivated plants.
N. I. Vavilov, a Russian geneticist and agronomist at the National Institute of Plant
Industry, USSR, relates to Studies on the Origin of Cultivated Plants published in
1926 and 1951. Vavilov launched an ambitious plant breeding programme that was
ever attempted to collect and assemble all of the useful germplasm of all crops. A
vigorous, world wide plant exploration, programme was launched and a systematic
survey for genetic resources of crop plants was started by him. He was interested in
the genetic diversity of crop plants and their centres of origin.
The centre of origin could be determined by an analysis of patterns of variation, and
according to Vavilov, the geographic region in which one found the greatest genetic
diversity was the center of origin for that particular crop.
From, his extensive studies, Vavilov, proposed eight centers of origin for most of the
cultivated plants of the world (Fig.1.1) :
32
Figure 1.1. Centres of origin for crop plants according to Vavilov (1951). 1. Chinese
Centre. 2. Indian Centre. 3. Central Asiatic Centre. 4. Near Eastern Centre. 5.
Mediterranian Centre. 6. Abyssinian Centre. 7. South-Mexican and Central American
Centre. 8. South American Centre.
On the basis of a large amount of supplementary data we have been enabled to locate
more exactly the regions of the origin of cultivated plants.
Southwestern Asia including Transcaucasia and the northwestern portion of India
originated soft wheats and rye as well as many grain Leguminosae, alfalfa, Persian
clover, etc. Here, especially in the western part of this area, is the home of the most
important fruit trees.
India is the native country of rice, sugar cane and many tropical plants.
The mountains and foothills of Eastern China are the home of many fruit trees, truck
crops and the soybean. The vast regions of Central Asia, investigated by us in detail in
1929, have proved alien to the primary process of form origination. In spite of some
former botanical suppositions, Central Asia and Siberia have had no influence upon
the origin of cultivated plants.
Abyssinia, though economically a country of no particular importance with its
cultivated area of only several million acres, shows a striking concentration of the
diversity of the genes of wheat, barley and many leguminous grain crops.
Certain countries bordering the Mediterranean are the home of the olive tree, the carol
tree, a series of original forage plants and Egyptian clover.
The 7th & 8th centers must be sought in America. In the New World the primary
process of form origination is narrowly localized; the regions showing a striking
species and varietal diversity occupy comparatively small territories concentrated in
Southern Mexico and Central America as well as in Peru and Bolivia. The home of
corn and of the upland cotton in all probability is Mexico and Central America,
whereas that of the potato is in Peru and Bolivia.
These centers have developed on the basis of an extremely rich wild flora. Here we
find conditions especially favorable to the development of species and varietal
diversity. These regions have proved equally favorable to civilizations and of course it
33
is no accident that the map showing the distribution of the chief sources of food plants
essentially coincides with that of the distribution of the first agricultural civilizations.
The mountain and foothill regions in the subtropics are the most remarkable places for
comprehending the evolution of cultivated plants as well as of many wild species.
In these regions the beginnings of the evolutionary process manifest themselves in a
salient way especially when we compare the evolution of different species and genera.
The existence of such group evolution of different species and genera facilitates
greatly an understanding of the evolutionary process.
But it soon became apparent that the pattern is much more complex than what
Vavilov has thought of, since some crops do not have centers of diversity. (Fig. 1.2).
According to Harlan (1971) there are three independent systems each with a center
and a non center. According to him no single model will explain agricultural origins
and he recognizes a humanistic no-model, model to explain the origins of
domesticated plants, which is mainly a humanistic problem ‘Man took the initiative in
modifying his environment, and plants responded genetically to his activities’. Plant
domestication is an evolutionary process operating under the influence of human
activities.
Vavilov thought that areas of maximum genetic diversity, represented centers of
origin and that the origin of a crop could be identified by the simple procedure of
analysing variation patterns and plotting regions where diversity was concentrated. It
34
turned out that centers of diversity are not the same as centers of origin, yet many
crops do exhibit centers of diversity.
FIG. 1.2. Origin and evolution of plants according to Harlan.
The reasons for the origin of secondary centers of crop plants might be due to (Harlan,
1975)
(i)
A long history of continuous cultivation,
(ii)
Ecological diversity,
(iii)
Human diversity, different tribes are attracted to different races of a crop,
(iv)
Introgression with wild or weedy relatives or between different races of the
crop, which leads to hybridization, segregation and selection, and
(v)
The deliberate introduction of certain exotic plants by mail from one continent
to another during history.
Germplasm collections of world crop plants are made continuously at the following
institutes in the world

Food and Agricultural Organizations of the United Nations;

The RockfelIer Foundation;
35

The 'Ford Foundation;

The Consultative Group;

Eucarpia;

The United States Development and Agriculture;

The Vavilov Institute of the Soviet Union;

CSIRO of Australia;

The Kihara Institute of Japan;

The National Bureau of Plant Genetic Resources of India etc.
Seed storage facilities are available in large quantities at Fort Collins in the United
States of America at the National Seed Storage Laboratory. Other places for storage
of seed include : Bari (Italy); Braunschweig (West Germany); Izamin- (Turkey);
Japan, Bulgaria, Poland, United Kingdom and Australia.
Some of the most important crops in the world are the following:
(1) Wheat,
(2) Rice,
(3) Maize,
(4) Potato,
(5) Barley,
(6) Manioc,
(7) Oats,
(8) Sorghum,
(9) Soybean,
(10) Cane sugar,
(11) Beet sugar,
(12) Citrus,
(13) Cotton fiber,
(14) Cotton seed,
(15) Bean, Pea, Chickpea,
(16) Rye,
(17) Banana,
(18) Tomato,
(19) Millets,
(20) Sesame,
(21) Palm oil,
(22) Pea-nut,
(23) Sweet potato and yams, (24) Coffee,
(25) Tobacco,
(26) Rubber
(27) Cocoa and
(28) Tea.
1.6.4 Process of domestication of crop plants from their wild progenitors
36
Domestication of cultivated plants is an evolutionary process through human
intervention and the process involves a slow and gradual progression from the wild
state to incipient domesticated forms or species. But, the process differs from crop to
crop, some species evolve directly and some indirectly by a series of steps in their
evolution.
Harvesting wild grass seeds was the beginning of domestication by the gatherers. It is
always the selection that is associated with harvesting, which causes domestication.
Most of the seeds that do not shatter are harvested and most of the seeds that shatter
escape the harvest. The shattering character in cereals is simple, one or two gene
controlled. Domestication introduces into the crop plants a non-shattering, annual
habit with lack of seed dormancy from a wild, shattering, perennial habit and with
seed dormancy. This has been well exemplified in the evolution of rice crop (Oryza
sativa L.).
There has been a trend in all cereals called the ‘Sunflower effect’ i.e., from many
small inflorescences to a few or a single large inflorescence, which is usually
accompanied by an increase in the seed size. The head of a commercial cultivar of
sunflower, an ear of maize, or a head of modern grain-sorghum or grain-type, pearl
millet are strikingly different from their wild progenitors. (Harlan, 1975).
Domestication also introduces a trend towards lower protein and higher carbohydrate
content of cereals; increasing seed size and hence endosperm. The embryo is richer in
protein and oil but does not increase in the same proportion as the endosperm. This
type of selection results in increased seedling vigour.
Cultivated plants have the capacity to evolve rapidly. Rapid evolution is possible only
through some variation on the theme of the differentiation-hybridization cycle in
which variability already accumulated can be exploited. Mutations play an important
role as the sources of variability in crop plants. The crop-weed interaction is the only
system by which differentiation-hybridization cycles can be set up in cultivated
plants. This enhances variability and broadens the base for plant selection.
Several isolating barriers are known to exist which fragment the populations and are
kept genetically apart whereby differentiation occurs. They include: geographic and
ecological separation, difference in time of blooming, self-fertilization, and
translocation races, polyploid races, gametophytic factors, cryptic chromosomal
differences and meiotic irregularities. Differentiation again largely depends upon
genetic buffering i.e., the amount of redundancy of genetic information.
37
Under domestication, changes occur, until the end products are radically different in
appearance from their wild progenitors. Thus, domestication results in great
morphological changes without substantial change in the genetic background.
1.7
LET US SUM UP
It is clear from the above discussion, to solve the food problem, the protein deficiency
in food stuffs; and new introduction of plants to cultivation for increased production;
may all seem to have great potential value in economic botany apart from the
humanistic problems. There have been great many discussions in recent years about
food problems versus population growth. Some argue that the food that is produced at
present is sufficient for the humans but the problem resides in the mal-distribution or
imbalance. While this being true, the fact remains that more food is necessary to feed
the ever increasing population.
One of the solutions advocated is to bring about more land into cultivation, the unused
pasture land, meadows, forests and even deserts. This will be a costly affair in terms
of money and water requirements, even of land fertility.
Another possibility is modernizing agriculture in the underdeveloped nations by using
high yielding varieties of crop plants, use of high fertilizer doses, multiple cropping
which increase food production. Use of modern farm machinery also helps in greater
food production than conventional implements of agriculture.
An important factor in increased food production also resides in storing the produce
obtained after harvest i.e., better storing facilities and better distribution standards as
it was estimated in a survey in India the grain crop lost by rodents is 50 percent, 15
percent by cows, birds and monkeys; ten percent by insects, 15 percent lost in storage
and transit and 15 percent in milling and processing, amounting to 105 percent of the
crop! (Heiser, 1973).
It is hard to believe that at the present rate of population growth, i.e., if the population
were to be doubled by 2050 A.D., the food problem remains a staggering one. The
chief advocates of the solution for this 'twin-problem' i.e., the food problem and the
population explosion can be partly circumvented by modern innovations in the
manufacture of synthetic foods apart from green revolution and birth control
respectively.
38
In the rest of the book a detailed account of the different crop plants of economic use
are discussed in relation to man from the standpoint of their origin, and distribution,
ecology, history, cultivation, botany of the plant, varieties, cytogenetics, chemical
constituents and economic uses, diseases and pests.
The most recent botanical names for each plant is given along with the valid name of
the family and vernacular names in fourteen Indian languages to familiarize the local
names in different Indian languages to their botanical names and create awareness
among non-botanists as well as botanists. It is of common experience, many
medicinal plants are known by local names and their proper identity unknown. An
earnest attempt is made towards this direction in this book. .
Statistics figures are given for each crop both for world and India giving details of
.area of cultivation in hectares and total production (in million metric tonnes). These
tables give an idea of distribution of the crops in world and in India and hence a
separate discussion is not included in the text as they are self explanatory.
For each crop discussed in the book under the heading 'ecology' mention has been
made regarding the soils, the type of soil favorable for growing the respective crop.
1.8
CHECK YOUR PROGRESS : KEY
1. i. Your answer may be as follows:
 Change energy consumption habits
 Purchase energy efficient alternatives
 Adjustment of thermostat
 Use the minimum amount of lighting
 Walk, cycle or use public transportation wherever possible.
 Maintain equipment regularly.
ii.
1.9
Adopt techniques to produce less waste such as: reduce, reuse, and recycle.
Recycle paper, clear and coloured glass, mixed plastics and cans. Utilize
all materials to the end of their lifecycle and compost any organic waste.
ASSIGNMENTS/ ACTIVITIES
39
It is compulsory for every student to complete an assignment/ activity/ project work
from any known prospects of present study. Explain the following (any one):
1.
Plant biodiversity especially in Indian concern.
2.
Sustainable development
3.
Origin of crop plants & their domestication
4.
Vavilov world centres of primary domesticated plants
1.10 REFERENCES/ FURTHER READINGS
Anderson, E. 1952. Plants. man and life. Little Brown, Boston.
Child, R.1974. Coconuts IInd edition. Lo ngmans, London.
Gadgil, M. 1992. Biodiversity – Time for Bold Steps. In : Survey of the Environment,
The Hindu, Madras. pp. 21-23.
Good, R. 1953. Geography of Flowering Plants. Longmann Green and Co. London.
Harlan, JR. 1975. Crops and Man. American Society of Agronomy, Madison,
Wisconsin.
Hasna, AM. 2007. Dimensions of sustainability. Journal of Engineering for
Sustainable Development: Energy, Environment, and Health 2 (1) : 47–57.
Hieser, B Charles Jr. 1973. Seed to civilization. The Story of Man’s Food. W H
Freeman & Co., San Francisco.
Khoshoo, TN. 1991. Environment Concerns and Strategies. Ashish Publishing House,
New Delhi.
León, J. 1987. Botánica de los cultivos tropicales. LICA. San José, Costa Rica.
Martínez, JL. 1984. Pasojeros de Indias. Alianza Universidad, Madrid.
Rindos, D. 1984. The origins of agriculture. An evolutionary perspective. Academic,
Fla Orlando, USA.
Stivers, R. 1976. The Sustainable Society: Ethics and Economic Growth. Westminster
Press, Philadelphia.
40
United Nations Division for Sustainable Development (UNDSD). 2007. Documents :
Sustainable Development Issues.
Vavilov, NI. 1949-1951. The origin, variation, immunity and the breeding of
cultivated plants. Waltham. Chronica Botanica 131(16) : 1366.
Vavilov, NI.1931. Mexico and Central America as the principle centre of origin of
cultivated plants in the New World. Bull. Appl. Bot. Genet Plant Breed., 26 : 135199.
Will Allen. 2007. Learning for Sustainability: Sustainable Development.
World Health Organization (WHO). 2005. World Summit Outcome Document.
41
UNIT - III
Structure
1.11
1.12
1.13
1.14
1.15
1.16
1.17
1.18
1.19
1.20
1.21
Introduction
Objectives
Green Revolution
1.13.1 Green Revolution in India : History
1.13.2 Methods of Green Revolution
1.13.3 Consequences of Green Revolution
1.13.4 India’s Second Green Revolution
Innovations for Meeting World Food Demands
1.14.1 Innovation for Meeting World Food Demand through Innovation in
Science & Technology
1.14.2 Beyond the Green Revolution : Gains from Agriculture R&D
1.14.3 A Need for Sustained and Increasing Investments in Agriculture R&D
1.14.4 New Institutions and Partnerships for Scientific Research and
Extension
1.14.5 The Future Funding of R&D for Agriculture
Forestry in India
1.15.1 Plantation
1.15.2 Selection and choice of plant species
1.15.3 Selection of site
1.15.4 Pest Problems
1.15.5 Species Selection
1.15.6 Benefit of plantation
1.15.7 Planting the plants
1.15.8 Plants used as avenue tree for shade
1.15.9 Plants used for pollution control
1.15.10
Plants used for aesthetic value
Extinction
1.16.1 Extinction : Definition
1.16.2 Pseudoextinction
1.16.3 Causes of Extinction
1.16.4 Genetics and demographic phenomena
1.16.5 Co-extinction
Environmental Status of Plants based on IUCN
1.17.1 The Global Strategy for Plant Conservation
Let us sum up
Check your progress : the key
Assignments/ Activities
References/ Further Readings
42
1.11 INTRODUCTION
The President of India in his address to the nation on the 50th year of India’s
independence mentioned of few landmark scientific achievements. The near
self-sufficiency in food and the agricultural transformation was one amongst
them. Slow growth in total wheat production up to 1965 necessitated a largescale food grain import by India under the soft (Public Law) PL - 480 system.
The series of agricultural changes that happened after 1965 in cereal
production was called “Green Revolution”.
Many underestimated the impact of change and rated green revolution as just
an increase in the food grain production. But it was the decision of the
scientists, extension functionaries, policy makers, political system and above
all the Indian farmer to go in for major changes, alterations and improvements
in his way of farming. By 1970 the impact of the green revolution made many
visionaries predict that India will become self sufficient in food grain
production. The 80s made us believe that India will be able to construct
adequate buffer stock to thwart the adverse weather and other calamities. The
1990s made us dream that we must be able to export some quantity of wheat.
During crop year 2000, India harvested 76 million tonnes (MT) of wheat, an
unsurpassed record. India continues to remain the second largest producer of
wheat in the world.
India now has about 40 million tonnes of surplus grain mainly wheat (> 25 MT)
and this has stabilized the food grain price and improved the per capita
consumption of the grain.
1.12 OBJECTIVES
The main objective of this unit is to awareness on agriculture sustainability
and importance of ecological management. The major objectives of present
study are :

To understand the green revolution and its consequences;

To study the importance of plants in functioning and stability of ecosystem;

To understand the importance of food value;

To study the extinction and its process;

To study the status of plants based on IUCN categories of threat.
43
1.13 GREEN REVOLUTION
Green revolution usually refers to the transformation of agriculture that began
in 1945. One significant factor came at the request of the Mexican
government to establish an agricultural research station to develop more
varieties of wheat that could be used to feed the rapidly growing population of
the country. In 1943 Mexico imported half its wheat; in 1956, the Green
Revolution had made Mexico self-sufficient; by 1964, Mexico exported half a
million tons of wheat. The associated transformation has continued as the
result of programs of agricultural research, extension, and infrastructural
development, instigated and largely funded by the Rockefeller Foundation,
along with the Ford Foundation and other major agencies. Many agronomists
state that the Green Revolution has allowed food production to keep pace
with worldwide population growth while others state that it caused the great
population increases seen today. The Green Revolution has had major social
and ecological impacts, making it a popular topic of study among sociologists.
The term "Green Revolution" was first used in 1968 by former USAID director
William Gaud, who noted the spread of the new technologies and said,
"These and other developments in the field of agriculture contain the makings
of a new revolution. It is not a violent Red Revolution like that of the Soviets,
nor is it a White Revolution like that of the Shah of Iran. I call it the Green
Revolution."
1.13.1
Green Revolution In India : History
The world's worst recorded food disaster happened in 1943 in British-ruled
India, known as the Bengal Famine, an estimated four million people died of
hunger that year alone in eastern India (that included today's Bangladesh).
The initial theory put forward to 'explain' that catastrophe was that there as an
acute shortfall in food production in the area.
However, Indian economist Amartya Sen (recipient of the Nobel Prize for
Economics, 1998) has established that while food shortage was a contributor
to the problem, a more potent factor was the result of hysteria related to World
War II which made food supply a low priority for the British rulers. The hysteria
was further exploited by Indian traders who hoarded food in order to sell at
higher prices.
44
Nevertheless, when the British left India four years later in 1947, India
continued to be haunted by memories of the Bengal Famine. It was therefore
natural that food security was a paramount item on free India's agenda. This
awareness led, on one hand, to the Green Revolution in India and, on the
other, legislative measures to ensure that businessmen
With the experience of agricultural development begun in Mexico by Norman
Borlaug in 1943 judged as a success, the Rockefeller Foundation sought to
spread the Green Revolution to other nations. The Office of Special Studies in
Mexico became an informal international research institution in 1959, and in
1963 it formally became CIMMYT, The International Maize and Wheat
Improvement Center.
In 1961 India was on the brink of mass famine. Norman Borlaug was invited to
India by the adviser to the Indian minister of agriculture M. S. Swaminathan.
Despite bureaucratic hurdles imposed by India's grain monopolies, the Ford
Foundation and Indian government collaborated to import wheat seed from
CIMMYT. Punjab was selected by the Indian government to be the first site to
try the new crops because of its reliable water supply and a history of
agricultural success. India began its own Green Revolution program of plant
breeding, irrigation development, and financing of agrochemicals.
India soon adopted IR8 - a rice semi-dwarf variety developed by the
International Rice Research Institute (IRRI) that could produce more grains of
rice per plant when grown properly with fertilizer and irrigation. In 1968, Indian
agronomist S.K. De Datta published his findings that IR8 rice yielded about 5
tons per hectare with no fertilizer, and almost 10 tons per hectare under
optimal conditions. This was 10 times the yield of traditional rice. IR8 was a
success throughout Asia, and dubbed the "Miracle Rice". In the 1960s, rice
yields in India were about two tons per hectare; by the mid-1990s, they had
risen to six tons per hectare. In the 1970s, rice cost about $550 a ton; in 2001,
it cost less than $200 a ton. India became one of the world's most successful
rice producers, and is now a major rice exporter, shipping nearly 4.5 million
tons in 2006.
Famine in India, once accepted as inevitable, has not returned since the
introduction of Green Revolution agriculture.
45
However, the term "Green Revolution" is applied to the period from 1967 to
1978. Between 1947 and 1967, efforts at achieving food self-sufficiency were
not entirely successful. Efforts until 1967 largely concentrated on expanding
the farming areas. But starvation deaths were still being reported in the
newspapers. In a perfect case of Malthusian economics, population was
growing at a much faster rate than food production. This called for drastic
action to increase yield. The action came in the form of the Green Revolution.
The term "Green Revolution" is a general one that is applied to successful
agricultural experiments in many Third World countries. It is NOT specific to
India. But it was most successful in India.
1.13.2
Methods of Green Revolution
There were three basic elements in the method of the Green Revolution:
1)
Continued expansion of farming areas;
2)
Double-cropping existing farmland;
3)
Using seeds with improved genetics.
Continued expansion of farming areas
The area of land under cultivation was being increased right from 1947. But
this was not enough in meeting with rising demand. Other methods were
required. Yet, the expansion of cultivable land also had to continue.
So, the Green Revolution continued with this quantitative expansion of
farmlands. However, this is NOT the most striking feature of the Revolution.
Double-cropping existing farmland
Double-cropping was a primary feature of the Green Revolution. Instead of
one crop season per year, the decision was made to have two crop seasons
per year.
The one-season-per-year practice was based on the fact that there is only
natural monsoon per year. This was correct. So, there had to be two
"monsoons" per year. One would be the natural monsoon and the other an
artificial 'monsoon.'
46
The artificial monsoon came in the form of huge irrigation facilities. Dams
were built to arrest large volumes of natural monsoon water which were
earlier being wasted. Simple irrigation techniques were also adopted.
Using seeds with superior genetics
This was the scientific aspect of the Green Revolution. The Indian Council for
Agricultural Research (which was established by the British in 1929 but was
not known to have done any significant research) was re-organized in 1965
and then again in 1973. It developed new strains of high yield value (HYV)
seeds, mainly wheat and rice but also millet and corn. The most noteworthy
HYV seed was the K68 variety for wheat.
The credit for developing this strain goes to Dr. M. P. Singh who is also
regarded as the hero of India's Green revolution.
1.13.3
Consequences of Green Revolution
Statistical Results of the Green Revolution
a. The Green Revolution resulted in a record grain output of 131 million tons
in 1978-79. This established India as one of the world's biggest agricultural
producers. No other country in the world which attempted the Green
Revolution recorded such level of success. India also became an exporter
of food grains around that time.
b. Yield per unit of farmland improved by more than 30 per cent between
1947 (when India gained political independence) and 1979 when the
Green Revolution was considered to have delivered its goods.
c. The crop area under HYV varieties grew from seven per cent to 22 per
cent of the total cultivated area during the 10 years of the Green
Revolution. More than 70 per cent of the wheat crop area, 35 per cent of
the rice crop area and 20 per cent of the millet and corn crop area, used
the HYV seeds.
Economic results of the Green Revolution
47
a. Crop areas under high-yield varieties needed more water, more fertilizer,
more pesticides, fungicides and certain other chemicals. This spurred the
growth of the local manufacturing sector. Such industrial growth created
new jobs and contributed to the country's GDP.
b. The increase in irrigation created need for new dams to harness monsoon
water. The water stored was used to create hydro-electric power. This in
turn boosted industrial growth, created jobs and improved the quality of life
of the people in villages.
c. India paid back all loans it had taken from the World Bank and its affiliates
for the purpose of the Green Revolution. This improved India's
creditworthiness in the eyes of the lending agencies.
d. Some developed countries, especially Canada, which were facing a
shortage in agricultural labour, were so impressed by the results of India's
Green Revolution that they asked the Indian government to supply them
with farmers experienced in the methods of the Green Revolution. Many
farmers from Punjab and Haryana states in northern India were thus sent
to Canada where they settled (That's why Canada today has many
Punjabi-speaking citizens of Indian origin). These people remitted part of
their incomes to their relatives in India. This not only helped the relatives
but also added, albeit modestly, to India's foreign exchange earnings.
Sociological results of the Green Revolution
The Green Revolution created plenty of jobs not only for agricultural workers
but also industrial workers by the creation of lateral facilities such as factories
and hydro-electric power stations.
Political results of the Green Revolution
a. India transformed itself from a starving nation to an exporter of food. This
earned admiration for India in the comity of nations, especially in the Third
World.
b. The Green Revolution was one factor that made Mrs. Indira Gandhi (191784) and her party, the Indian National Congress, a very powerful political
force in India (it would however be wrong to say that it was the only
reason).
48
Limitations of the Green Revolution
a.
Even today, India's agricultural output sometimes falls short of
demand. The Green Revolution, howsoever impressive, has
thus NOT succeeded in making India totally and permanently
self-sufficient in food. In 1979 and 1987, India faced severe
drought conditions due to poor monsoon; this raised questions
about the whether the Green Revolution was really a long-term
achievement. In 1998, India had to import onions. Last year,
India imported sugar.
b.
However, in today's globalised economic scenario, 100 per cent
self-sufficiency is not considered as vital a target as it was when
the world political climate was more dangerous due to the Cold
War.
c.
India has failed to extend the concept of high-yield value seeds
to all crops or all regions. In terms of crops, it remains largely
confined to food grains only, not to all kinds of agricultural
produce. In regional terms, only Punjab and Haryana states
showed the best results of the Green Revolution. The eastern
plains of the River Ganges in West Bengal state also showed
reasonably good results. But results were less impressive in
other parts of India.
d.
Nothing like the Bengal Famine can happen in India again. But it
is disturbing to note that even today, there are places like
Kalahandi (in India's eastern state of Orissa) where famine-like
conditions have been existing for many years and where some
starvation deaths have also been reported. Of course, this is
due to reasons other than availability of food in India, but the
very fact that some people are still starving in India (whatever
the reason may be), brings into question whether the Green
Revolution has failed in its overall social objectives though it has
been a resounding success in terms of agricultural production.
e.
The Green Revolution cannot therefore be considered to be a
100 percent success.
49
Since the beginning of agriculture, people have been working to improving
seed quality and variety. But the term ‘Green Revolution’ was coined in the
1960s after improved varieties of wheat dramatically increased yields in test
plots in northwest Mexico. The reason why these ‘modern varieties’ produced
more than traditional varieties was that they were more responsive to
controlled irrigation and to petrochemical fertilizers. With a big boost from the
international agricultural research centres created by the Rockefeller and Ford
Foundations, the ‘miracle’ seeds quickly spread to Asia, and soon new strains
of rice and corn were developed as well.
By the 1970s the new seeds, accompanied by chemical fertilizers, pesticides,
and, for the most part, irrigation, had replaced the traditional farming practices
of millions of farmers in developing countries. By the 1990s, almost 75% of the
area under rice cultivation in Aisa was growing these new varieties. The same
was true for almost half of the wheat planted in Africa and more than half of
that in Latin America and Asia, and more than 50% of the world's corn as well.
Overall, a very large percentage of farmers in the developing world were using
Green Revolution seeds, with the greatest use found in Asia, followed by Latin
America.
1.13.4
India’s Second Green Revolution
400 million tons of food grain production as opposed to about 214 million tons
in 2006-07 is the target of “Second Green Revolution. It is unlikely to happen
to-morrow or next year, but it possibly may happen by 2020. To achieve the
forgoing amount of production a growth rate of 5 to 6% in agricultural sector
has to be maintained over next 15 years.
Current growth rate in this sector is stagnant or at best 2% (in last ten years).
The latter has depleted the country’s food stock and forced the government to
negotiate import of 5 million tons of wheat. With practically no more land to
50
farm and some depletion of the agricultural land, this miracle is not easy to
achieve. Science and technology has to play its big role. High productive
seeds, private sector involvement and expenditure on long stalled irrigation
schemes are key to achieving higher production.
Population growth in India is at the rate of 1.8 to 2.2% a year. With rising
population and slow rate of agricultural growth, situation is likely to get
alarming if not worst next in 5 to 8 years. Food self-sufficiency of nineties will
be a forgotten achievement. Shortages will loom. Famines may not visit India,
but shortages will visible shaken the national confidence.
To quote an old Chinese saying – "When price of rice goes far beyond what a
common man can pay, heaven ordains a new ruler". Agrarian distress is much
more worst than industrial unrest. It has already ejected an otherwise a finely
run government of National Democratic Alliance in 2004. Farmer suicides and
other agrarian issues prevented some state voters from voting for the NDA.
Situation is no different toady, except that timely rains this year have
brightened the prospect of the Rabi (wheat) crop.
Requirement to start the IInd Green Revolution
If the gains of “First Green Revolution” 1970-90 are to be strengthened, then a
Second Green Revolution is to be initiated. The First Green Revolution was
made possible with the availability of miracle wheat variety, electricity at the
farms and land reforms. The triumvirate of Swaminathan, Venkatraman &
Indira Gandhi, provided the leadership. With its success, the begging bowl
stereotype of India in the West was laid to rest. Instead a new India, still poor
but confidant, proving IR, BPO and KPO service to the world was born. There
was a 15 years respite from a bad news on the agricultural front. A lot of food
grains were exported. We in the West, with Indian heritage, who still prefer
Indian basmati and daals, loved to purchase all things Indian. We still buy the
same but are also reading a few bad reports like depleted reserve food stocks
etc. Wheat is arriving from Australia. It has dampened the inflationary mood in
the country a bit. Luckily, the rains of February and March have helped. Need
to import the full 5 million tons of wheat shortfall may not be necessary. The
issue at hand is not today but what is likely to happen in next 10 years, if the
agricultural production stayed sluggish.
Hence Government of India is back into square one i.e. what needs to be
done to trigger higher agricultural growth in India. We may wish to call it the
51
“Second Green Revolution”. But it is a high-end initiative with both Federal
and State governments are full participants.
It will also require:
1. Genetically modified (GM) seeds to double the per acreage production i.e.
technology,
2. Private sector to develop and market the usage of GM foods i.e. efficient
marketing of the ideas,
3. Linking of rivers as much as economically possible to bring surplus water
of one area to others i.e. linking of the rivers.
Not only that, a significant contribution is to be made by the farmers
themselves. They have to get out of the ancient mode of being peasant
farmers on small land holdings. They have to become businessmen, who
trade in agricultural products. Just like any other businessmen they have to
look for the most economical way to boost productivity and profits to
themselves. Splitting of land holding, after a father passes away, into multiple
children have depleted the economic viabilities of farms. Farm economics
have to be revisited and economic size of the farm re-established. Continued
dependency on government bailout during any crisis has to be minimized.
Lesser the government involved, more likely is that controls and state trading
in grains will be eliminated. It requires farmers to become responsible
businessmen.
Consumer has to grow up a bit also. “Genetically Modified Food” is here to
stay. It is the salvations of the rapidly increasing population. Opposition to the
GM food in India is wholly politically motivated. It has to be ended in favor of
adopting new techniques to boost productivity. Forty years back, a similar
political lobby opposed the introduction of Mexican wheat variety in India. This
in fact began the first green revolution. Today, results of this wheat variety are
wonderful. Now a similar campaign to demonize GM food is under way.
Believe it or not some of these well-tried concepts are India’s ultimate
salvation.
GM Food and India
GM food is new and its concept is not well understood, especially in India.
Communications are faulty. Everybody who wishes to oppose US in more
52
than one-way, have found a new way to continue his or her tirade against the
GM food. GM food is an American private innovation. Governments had
nothing to do with it. Private sector innovated it and marketed it. Today a
significant amount of daily-consumed foodstuff in North America is GM food.
In a nutshell GM is about improving the crop (such as yield), pest resistance,
herbicide tolerance etc. to name a few. It will improve yield from the same
fields by about 25% to 50%. It is something every farmer would wish to have.
It is something a consumer would wish to have as pest free food gets to the
dinner table. Shortages would cease to exist.
There is definitely a health risk with GM food. Because it is a recent
innovation, its long term and very long-term impact on human body is not well
understood. But North American consumer is the best laboratory for it. They
have been consuming it for the last 15 years. If any untoward issue surfaces,
they will be the first to feel it. Crop area under GM food production in last 10
years in US alone has increased 50 times. In India, maize, oil seeds, fruits &
vegetables, soybeans, wheat crop yields will dramatically increase. Other
beneficiaries will be cotton, potato, onion etc.
Building on this success in US, President George Bush during his March 2005
visit, began a $100 million initiative - Indo-US Knowledge Initiative in
Agricultural Research and Education. Its precise intentions are to begin the
Second Green Revolution in India. Its details are not well known. One reason
for a bit of secrecy is the political sensitivities in India. Without knowing the
details and analyzing the benefits, people who oppose it have called it as an
Indian sell out to American corporate interests. Even if a small (20%) land
comes under GM cultivation in India, it will add 30 to 60 million tons of
additional food for the consumer. Not only that, farmer on these parcels of
lands will be lifted out of poverty. This is just the beginning. Fifteen years
hence, GM food may lead the way to lift all the rural population out of poverty.
Why Do We Wish that Private Sector, instead of Government Manage the
Second Green Revolution.
There are obvious reasons for wishing corporate participation in India’s
Second Green revolution.
First, the above-mentioned triumvirate, which guaranteed the success of the
First Green Revolution, may be difficult to form. Leadership issues and party
politics will make any government initiative difficult to succeed. Make up of
53
governments in last 10 years and 10 more years to come, has been and will
be a hotchpotch of political ideology. Hence, it will be harder to find a coherent
policy for some time to come.
Second, efficient delivery of services will be the key to higher agricultural
output. Governments, especially the democratic governments, are not geared
for efficiency and effective delivery of any services. Current food marketing
and storage system all owned by the government (FCI) is key example.
Rough estimates indicate that anywhere from 20 to 30% of the food is spoiled,
before it hits the dinner table.
Thirdly, US multinationals (Wal-Mart & Monsanto) would prefer to deal with
the private sector than with government officials.
Private sector in India is very willing to enter this profitable sector. A joint
venture between Bharti Telco’s Milltal and E. L. Rothschild (a British
investment firm) is making foray into export of fresh fruits & vegetables. It has
leased 50,000 acres of land in Punjab and will grow vegetables for export to
Europe. It will also become a laboratory for new ideas. A $50 million
investment initially, is expected to export $15 million worth of produce in the
current year rising rapidly in next three years as shipping and storage issues
are overcome. Reliance, which in last 15 years has become an industrial
giant, has plans to invest about $6 Billion in agricultural retail sector. Their
retail outlets will be linked to farms in Punjab, Haryana, Maharashtra and
West Bengal. This has potential to revolutionize handling and distribution of
the food in the country. It will also deliver better returns to the farmers. The
forgoing is a US model where corporate giants like Cargill run distribution and
manage farm output. The present government in India has to readjust its
policy to let the private sector play a role. The latter is most likely to succeed.
Success of ventures like this will persuade governments to give up its
complete control over food distribution in the country.
Linking of the Rivers to Transfer Surplus Water to deficient
Areas
It is no longer a pipe dream, although there are a few un-surmountable
obstacles. East India (Brahamaputra valley) is surplus in water. This water
during July to October each year causes havoc. This could be transferred to
West and South. Similarly rainy season surplus water in the Gangetic plains
54
can reach the southern India and develop agriculture in areas unknown
before.
But there are problems. Bangladesh would not permit digging of any canal
from Assam to Central India through its territory, even though; it benefits them
as much as it benefits India.
Again, the Gangetic plains are at lower elevation and 400 miles wide
mountain ranges, rising at places from 3,000 feet to 6,000 feet in central
India’s geography prevents any easier transfer of water.
Hence, although agriculture will benefit immensely with both these river link
schemes, solutions are not forthcoming in next 20 to 30 years. Bangladesh
issue may never reach solution. They would prefer to float in floodwater year
after year than to let India dig a canal through its territory. Hence water of
Brahamaputra may never reach central India.
For north-south link of rivers, technology may some day, make digging of
tunnel-canal link easier. That is a hope. A garland canal link traveling the
contours of Indian peninsula is possible. It has been previously suggested but
has not gone beyond the feasibility stage. It will circumvent the mountains in
central India but does not deliver water to the arid lands of south-central India,
where it is needed most. Moreover the garland canal is useless until it gets a
huge water supply from the Assam valley.
Without loosing heart on possible river links, India has to explore other
possibilities. A scheme to transfer Gangetic basin water westwards towards
Haryana, Rajasthan and Gujarat is a possibility. The latter scheme will be a
great engineering achievement. This, half the size of the original scheme, will
increase the land under cultivation by 15%. Impact on local economy of this
water will be huge.
India has about 150 million hectares of land under cultivation. This is down by
about 10% from land under cultivation 20 years back. Urban encroachment,
unprofitable cultivation, water logging etc. are key reasons of this reduction.
Of the total land under cultivation, only 45 million hectares are irrigated. This
delivers about 55% of the total food output. Rest of the 95 million hectares of
land is rain fed or ground water irrigated. This bulk of the land produces 45%
of the total food production. This latter is the area to concentrate most to
55
boost food output. Whereas progressive Indian farmers can experiment with
GM food in the irrigated lands, minor and major irrigation schemes have to
play a major role in boosting productivity in the un-irrigated areas. This is
where the state and federal governments have to play a bigger role.
Whether it is interlinking of the rivers or local irrigation schemes, something
more need to be done. Government initiatives are the key to the success.
Funding for the local schemes is to be readily made available. Current Budget
envisages a much higher level of funding for rural schemes. This increase is
partly an election year politics and partly to boost funds for the rural areas
which previously were not a top priority. Whether this increased availability of
funds will translate into start of much delayed irrigation initiatives or not, time
will tell. Usually any government schemes requires 3 to 4 years of paper work
before the first shovel of dirt is thrown at site and another 4 years to complete.
Any initiatives taken now will bear fruit in about 6 to 8 years. This time frame
on new projects is an acceptable consequence of democracy. Projects, which
are already in progress or on which progress is slow, can be expedited.
Speedily appropriated funds can to expedite projects already in the pipeline.
This will fill-up the gap before newer and bigger projects like river links
become a reality.
1.14 INNOVATIONS FOR MEETING WORLD FOOD
DEMANDS
1.14.1
Innovations for meeting world food demands
through Innovations in Science and Technology
With every generation, the world’s demand for food, feed, fuel & fiber changes
and grows. Increasing populations, evolving diets, and most recently, soaring
demand for biofuel production, have posed challenges to farmers to increase
grain production.
Eighty years ago, the development of hybrid corn sparked an agricultural
revolution helping us to more efficiently produce quality food and feed for our
country and the world. We are on the leading edge of a similar revolution that
is challenging farmers to also deliver a stable, sustainable fuel supply through
ethanol, biodiesel and other biofuel production.
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Global population has more than doubled since 1945 to reach 7 billion today,
and one billion inhabitants are added every 12 to 15 years. In addition,
incomes are improving in the developing world, which is expected to increase
demand in those countries for grain-fed meat. At the same time, developed
countries have increased interest in using crops to produce biofuels such as
ethanol, biobutanol and soy diesel to offset demand for costly petroleumbased fuels. This increased demand comes while land available for
agriculture is being lost to urban expansion. If agriculture is to meet this
growing demand, it is essential that producers increase yields on currently
available acreage. This too, will prevent marginal or protected land from being
placed into production.
Agriculture is a highly sophisticated field, in which scientific research, new
technologies and improved management practices help to maximize the yield
potential of every available acre. Continued research and a robust pipeline of
products and technologies promise to help farmers worldwide meet the
increased demand for food, feed and fuel in the 21st century.
Investments in agriculture research and development (R&D) have turned
agriculture in much of the developing world into a dynamic sector, with rapid
technological innovation accelerating growth and reducing poverty. However,
the technological challenges facing agriculture in the 21st century are
probably even more daunting than those of recent decades. Land and water
are becoming increasingly scarce, so the main source of growth to satisfy
increased demand for food and agricultural products will be through gains in
productivity.
All regions, especially the heterogeneous and risky rain fed systems of India,
need sustainable technologies to increase the productivity, stability, and
resilience of their production systems and to confront climate change. To
achieve this, public and private investment in research and development
(R&D) must increase and partnerships with the private sector, farmers, and
civil society must be strengthened in order to stimulate user demand for R&D,
increase market responsiveness and competitiveness, and ensure that the
poor benefit. Furthermore, advances in the biological sciences and
information sciences must be harnessed to enable smallholders to access
markets and increase the resilience of production systems important to the
poor.
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1.14.2
Beyond the
Agriculture R&D
Green
Revolution:
Gains
from
Since the 1960s, scientific plant breeding to develop improved crops suited to
smallholders – the green revolution – has been one of the major success
stories of development. Initiated by research centers of the Consultative
Group on International Agricultural Research (CGIAR), public breeding
programs in developing countries have released more than 8,000 improved
crop varieties over the past 40 years. Improved varieties not only boost yields,
they also make them more stable by reducing vulnerability to pests and
disease.
In the 1970s and 1980s following the main period of the green revolution, the
spread of improved crop varieties accounted for as much as 50 percent of
yield growth of food staples, more than doubling the estimated 21 percent
gains of the preceding two decades, with poor consumers being the main
beneficiaries. Without those gains, world cereal prices would have been 18-21
percent higher in 2000, and caloric availability per capita would have been 4-7
percent lower. Thirteen to fifteen million more children would have been
classified as malnourished and many more hectares of forest and other fragile
ecosystems would have been brought under cultivation.
But while improved varieties have been one of the major success stories of
development, and crop yields continue to improve, not all farmers and regions
have benefited equally. India has seen very incomplete adoption of improved
varieties, owing to the agro-ecological heterogeneity of the region, lack of
infrastructure, and other factors. Additionally, progress in developing varieties
that perform well under drought, heat, flood, and salinity has generally been
slower than for pest and disease resistance. Such advances will be essential
for adapting to climate change.
Beyond the genetic improvement of crops and animals, scientific and
technical gains are won by improving the management of crop, livestock, and
natural resource systems. The CGIAR invests about 35 percent of its
resources in sustainable production systems, twice the 18 percent on genetic
improvement. Much of this research exploits biological and ecological
processes to reduce the use of non-renewable inputs, especially agricultural
chemicals. An example of such an approach is “zero tillage”, which lowers
production costs while reducing greenhouse gas emissions and conserving
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soil. Other such systems include the use of nitrogen-fixing legumes or trees to
improve soil fertility, thereby reducing the need for chemical fertilizers while
also slowing erosion, and integrated pest management, which reduces the
use of pesticides.
1.14.3
A Need for Sustained and Increasing Investments in
Agriculture R&D
Agricultural productivity improvements have been closely linked to
investments in agricultural research and development (R&D). Published
estimates of rates of return on R&D and extension investments in the
developing world average 43% a year. Despite this high return on investment,
agricultural science remains grossly under funded in developing countries.
Global and national market failures continue to induce serious
underinvestment in R&D and in related extension systems, especially in the
agriculture-based economies of Africa.
In the developing world, private investment in agricultural R&D is very limited
– 94% of the investment is from the public sector. But growth in public sector
spending has slowed sharply in the past decade and as a share of agricultural
GDP, remains a fraction of the public investment in industrialized countries. In
the 1990s, public R&D spending in India fell in nearly half of the countries of
the region. This declining trend is partly due to political considerations, where
decision-making emphasizes short-term payoffs rather than long-term benefits
and partly due to disincentives for small countries to spend scarce resources
on agricultural science when they can often “free ride” on the efforts of larger,
more affluent countries. But relying on “spillovers” for productivity gains has
inherent risks and limits given the uniqueness of Africa’s agro climatic
conditions and crops.
A third to a half of current R&D investments may be for “maintenance
research” to deliver continued yield stability and insure against outbreaks of
new pathogens. The recent emergence of a new type of stem rust (Puccinia
graminis tritici), Ug99, in wheat clearly demonstrates why maintenance
research is critical. Given the narrow base of genetic resistance to the disease
in existing varieties in some of the world’s breadbaskets, losses are potentially
devastating. An international effort by plant breeders and pathologists is
underway to screen for resistant genotypes and get them into farmers’ fields
to prevent a global epidemic.
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1.14.4
New Institutions and Partnerships for Scientific
Research and Extension
Low spending on R&D is only part of the problem. To meet today’s rapidly
changing market demands, improving efficiency and effectiveness of R&D
requires collective action and partnerships involving a variety of actors in an
innovation systems framework. Many public research organizations face
serious institutional constraints that inhibit their effectiveness as well as their
ability to attract funds. These require serious reform. Furthermore, the high
fixed costs of much of today’s research put small and medium-sized countries
at a disadvantage for some kinds of research. A challenge is therefore how to
strengthen institutions that finance and organize research on a multinational
basis.
The new world of agriculture is opening space for a wider range of actors in
innovation, including farmers, the private sector and civil society. Linking
technological progress with institutional innovations and markets to engage
this diverse set of actors is at the heart of future productivity growth.
Extension programs are shifting from a delivery model that prescribes
technological practices to focusing on building capacity among rural people to
empower them to identify and take advantage of available technological and
economic opportunities.
For example, new decentralized approaches to plant breeding that involve
farmers in the early stages of breeding and varietals selection can both speed
varietals development and dissemination to 5-7 years, half the 10-15 years in
a conventional plant breeding program. Partnerships between R&D and
farmers’ organizations aim to enhance the demand for innovation by bringing
farmers’ voices into R&D decision-making.
1.14.5
The Future Funding of R&D for Agriculture
The need to increase funding for agricultural R&D throughout the developing
world cannot be overstated. Most urgent is to reverse the stagnant funding of
agricultural R&D and broader knowledge systems in India. This must be
driven by national leadership and funding, but will also require substantially
increased and sustained support from regional and international
organizations.
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Continuing progress, especially in extending benefits of R&D to agriculturebased countries and less-favored regions elsewhere, depends critically on
research in these environments on improving crop, soil, water, and livestock
management and on developing more sustainable and resilient agricultural
systems. These technological innovations, often location-specific, must be
combined with institutional innovations to ensure that input and output
markets, financial services, and farmer organizations are in place for broad
based productivity growth.
1.15 FORESTRY IN INDIA
It is well known that India had a great spread of forests in the Vedic and
Puranic era. The population was small and there was no pressure on the
products the people needed from them. During the Medival Ages, the Muslim
rulers because of their fondness for shikar gave consideration to protecting
forests.
The forests scene however changed rapidly after the advent of the British.
They considered India as an inexhaustible source of durable and ornamental
timber for the navy and for other purposes. Some of the finest plants of
valuable varieties were cut down totally ignoring their replacement. It was
recognized much later that forest resources are not inexhaustible and rules
were framed for proper management and conservation of forests. The first
step was the organization of a forestry department in 1858. In 1884 the first
inspector general of forests was appointed. The first Indian Forest Act was
enacted in 1865. In 1894 a forest policy was enunciated.
In independent India, due to rapid industrialization, urbanization and increase
in human as well as cattle population, there is reduction in forest cover from
22.8% to about 14%.
The forest policy lays that one third of the land area of the country should be
under forest cover. That means in India proper management and conservation
of traditional forests is the need of the day along with plantation of more plants
in available space. Social forestry is one effort in this direction; it is concerned
with tree plantation in and around the human settlements. The objective being
to make available within easy reach the basic needs of the people living in
that area with respect to food, fuel, fibre, fodder and furniture and to restore
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the fast deteriorating ecological balance. For the success of such programme,
active involvement, co-operation and participation of the people form the
various sections of the society is of utmost importance. Social forestry sets
the stage for such programme. The philosophy behind it can be expressed as
“it is a scheme of plantation of useful plants in the society, for the society and
by the society”.
The term social forestry was first used by the National Commission on
Agriculture in 1976. The NCOA realized that a stage had come when the
country could not depend for forest produce on traditional forests only and
that extending forest activity outside the forest areas was imperative. The
commission had discussed the scope of social forestry and had also indicated
the areas where it could be practiced. It is now recognized that it covers the
following.
1. Creation of wood-lots on the village common lands, government waste
land and panchyat lands.
2. Planting of tress on road, canal and rail sides. This along with planting on
wastelands has been called extension forestry.
3. Afforestration of degraded government forests which have suffered from
unauthorized removal of the forest produce by villagers.
4. Planting of plants on and around agricultural fields, hedges, compounds
and on marginal private lands. This component has been called farm
forestry or agro-forestry.
5. Plantation around habitation, urban and industrial area.
The area available under different categories for plantation of this type was
worked out by the fuel wood study committee of the Planning Commission in
1982.
In the fifth plan, forest plantation schemes were restricted to government
lands. A Central Social Forestry Schemes embracing degraded government
forest land and village common lands was first taken in hand during the fifth
plan. But according to the decision of the national Development Council
(NDC) this scheme along with many others was transferred to the states from
the year 1979-80. The Central Government soon realized that inspite of the
decision of NDC, it was necessary for the centre to run a centrally sponsored
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social forestry scheme to encourage the raising of fuel plants in a big way and
a district level programme was introduced in each state. Farmers were
approached and an interest in them was created in planting plants in their
agricultural fields, marginal lads, compounds, hedges, shelter belts and in
small woodlots. A new component of distribution of seedlings to the public,
free of cost, was introduced in the scheme. The seedlings were to be of fuel
and fruit plants. Later on “a tree for every child” programme was launched.
The object was to encourage every child to grow a fruit tree which would
provide a more balanced diet.
1.15.1
Plantation
The selection of appropriate tree variety for planting at a locality depends on
two parameters, first the purpose which the tree is required to serve and the
second the physical and climatic characteristics of the sites. In social forestry,
production of fuel and small timber is the primary aim but fodder, fruits and
fibres have also to be kept in view alongwith the aesthetic value of the plant.
As no single tree species can meet all these requirement, it becomes
necessary to select a combination of species which can fulfill all or almost all
the requirements. Recently a concept of plus plant has developed i.e.
selection of plant having maximum number of above mentioned economically
important characters. In India a great diversity in climatic conditions is
present. On one hand extreme hot and humid regions of south are present
supporting luxuriant evergreen vegetation while on the other hand windy cold
Himalayas and deserts are present. Thus three broad climatic regions can be
recognized in India.
a)
Temperate region
b)
Sub-tropical region
c)
Tropical region.
1.15.2
Selection and choice of plant species
Plant selection is one of the most important decisions. Considering that most
plants have the potential to outlive the people who plant them, the impact of
this decision is one that can influence a lifetime. Match the plant to the site,
and both lives will benefit.
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The question most frequently asked of plant care professionals is “Which kind
of plant do you think I should plant?” Before this question can be answered, a
number of factors need to be considered. Think about the following questions:

Why is the plant being planted? Do you want the plant to provide shade, fruit,
or seasonal color, or act as a windbreak or screen? May be more than one
reason?

What is the size and location of the planting site? Does the space lend itself to
a large, medium, or small plant? Are there overhead or belowground wires or
utilities in the vicinity? Do you need to consider clearance for sidewalks,
patios, or driveways? Are there other plants in the area? Are there barriers to
future root growth, such as building foundations?

Which type of soil conditions exist? Is the soil deep, fertile, and well drained,
or is it shallow, compacted, and infertile?

Which type of maintenance are you willing to provide? Do you have time to
water, fertilize, and prune the newly planted plant until it is established, or will
you be relying on your garden or plant service for assistance?
Asking and answering these and other questions before selecting a plant will
help you choose the “right plant for the right place.”
Plant Function
Plants make our surroundings more pleasant. Properly placed and cared for,
plants increase the value of our real estate. A large shade plant provides relief
from summer’s heat and, when properly placed, can reduce summer cooling
costs. An ornamental plant provides beautiful flowers, leaves, bark, or fruit.
Evergreens with dense, persistent leaves can be used to provide a windbreak
or a screen for privacy. A plant that drops its leaves in the fall allows the sun
to warm a house in the winter. A plant or shrub that produces fruit can provide
food for the owner and/or attract birds and wildlife into your home landscape.
Splint plants decrease the glare from pavement, reduce runoff, filter out
pollutants, and add oxygen to the air we breathe. Splint plants also improve
the overall appearance and quality of life in a city or neighborhood.
Form and Size
64
A basic principle of modern architecture is “form follows function.” This is a
good rule to remember when selecting a plant. Selecting the right form
(shape) to complement the desired function (what you want the plant to do)
can significantly reduce maintenance costs and increase the plant’s value in
the landscape. When making a selection about form, also consider mature
plant size. Plants grow in a variety of sizes and shapes, as shown below.
They can vary in height from several inches to several hundred feet. Select a
form and size that will fit the planting space provided.
Depending on your site restrictions, you can choose from among hundreds of
combinations of form and size. You may choose a small-spreading plant in a
location with overhead utility lines. You may select a narrow, columnar form to
provide a screen between two buildings. You may choose large, vase-shaped
plants to create an arbor over a driveway or city splantt. You may even
determine that the site just does not have enough space for a plant of any
kind.
1.15.3
Selection of site
Selecting a plant that will thrive in a given set of site conditions is the key to
long-term plant survival. The following is a list of the major site conditions to
consider before selecting a plant for planting:

Soil conditions

Exposure (sun and wind)

Human activity

Drainage

Space constraints

Hardiness zone
Soil Conditions
The amount and quality of soil present in your yard can limit planting success.
In urban sites, the topsoil often has been disturbed and frequently is shallow,
compacted, and subject to drought. Under these conditions, plants are
continuously under stress. For species that are not able to handle these types
of conditions, proper maintenance designed to reduce stress is necessary to
ensure adequate growth and survival. Many arborists will, for a minor charge,
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take soil samples from your yard to test for fertility, salinity, and pH (alkalinity
or acidity). The tests will be returned with recommendations on ways to
improve poor soil conditions with fertilizers or soil amendments (sand,
compost, or manure) and will also help your local nursery or garden center
recommend plant species that will do well in the soils found on your site.
Exposure
The amount of sunlight available will affect plant and shrub species selection
for a particular location. Most woody plants require full sunlight for proper
growth and flower bloom. Some do well in light shade, but few plant species
perform well in dense shade. Exposure to wind is also a consideration. Wind
can dry out soils, causing drought conditions and damage to branches and
leaves during storms, and can actually uproot newly planted plants that have
not had an opportunity to establish root systems. Special maintenance, such
as staking or more frequent watering, may be needed to establish young
plants on windy sites.
Human Activity
This aspect of plant selection is often overlooked. The reality of the situation is
that the top five causes of plant death are the result of things people do: soil
compaction, underwatering, overwatering, vandalism, and the number one
cause—planting the wrong plant—account for more plant deaths than all
insect and disease-related plant deaths combined.
Drainage
Plant roots require oxygen to develop and thrive. Poor drainage can remove
the oxygen available to the roots from the soil and kill the plant. Before
planting, dig some test holes 12 inches wide by 12 inches deep in the areas
you are considering planting plants. Fill the holes with water and time how
long it takes for the water to drain away. If it takes more than 6 hours, you
may have a drainage problem. If so, ask your local garden center for
recommendations on how to correct the problem, or choose a different site.
Space Constraints
66
Many different factors can limit the planting space available to the plant:
overhead or underground utilities, pavement, buildings, other plants, visibility.
The list goes on and on. Make sure there is adequate room for the plant you
select to grow to maturity, both above and below ground.
Hardiness
Hardiness is the plant’s ability to survive in the extreme temperatures of the
particular geographic region in which you are planting the plant. Plants can be
cold hardy, heat tolerant, or both. Most plant reference books provide a map
of hardiness zone ranges. Although tropical areas are generally Zone 11,
higher elevations have cooler temperatures that may warrant adjustment to
the hardiness zone classification. Check with your local garden center for the
hardiness information for your region. Before you make your final decision,
make sure the plant you have selected is “hardy” in your area.
1.15.4
Pest Problems
Insect and disease organisms affect almost every plant and shrub species.
Every plant has its particular pest problems, and the severity varies
geographically. These pests may or may not be life threatening to the plant.
You should select plants resistant to pest problems for your area. Your local
ISA Certified Arborist, plant consultant, or extension agent can direct you to
information relevant to problem species for your location.
1.15.5
Species Selection
67
Personal preferences play a major role in the selection process. Now that
your homework is done, you are ready to select a species for the planting site
you have chosen. Make sure you use the information you have gathered
about your site conditions, and balance it with the aesthetic decisions you
make related to your personal preferences.
The species must be suitable for the geographic region (hardy), tolerant to the
moisture and drainage conditions of your soil, be resistant to pests in your
area, and have the right form and size for the site and function you have
envisioned.
Remember, the beautiful picture of a plant you looked at in a magazine or
book was taken of a specimen that is growing vigorously because it was
planted in the right place. If your site conditions tell you the species you
selected will not do well under those conditions, do not be disappointed when
the plant does not perform in the same way.
1.15.6
Benefit of plantation
Most plants and shrubs in cities or communities are planted to provide beauty
or shade. These are two excellent reasons for their use. Woody plants also
serve many other purposes and it often is helpful to consider these other
functions when selecting a tree or shrub for the landscape. The benefits of
plants can be grouped into social, communal, environmental, and economic
categories.
Social Benefits
We like plants around us because they make life more pleasant. Most of us
respond to the presence of plants beyond simply observing their beauty. We
feel serene, peaceful, restful, and tranquil in a grove of plants. We are “at
home” there. Hospital patients have been shown to recover from surgery
more quickly when their hospital room offered a view of plants. The strong ties
between people and plants are most evident in the resistance of community
residents to removing plants to widen streets. Or we note the heroic efforts of
individuals and organizations to save particularly large or historic plants in a
community.
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The stature, strength, and endurance of plants give them a cathedral-like
quality. Because of their potential for long life, plants frequently are planted as
living memorials. We often become personally attached to plants that we or
those we love have planted.
Communal Benefits
Even though plants may be private property, their size often makes them part
of the community as well. Because plants occupy considerable space,
planning is required if both you and your neighbors are to benefit. With proper
selection and maintenance, plants can enhance and function on one property
without infringing on the rights and privileges of neighbors.
City plants often serve several architectural and engineering functions. They
provide privacy, emphasize views, or screen out objectionable views. They
reduce glare and reflection. They direct pedestrian traffic. They provide
background to and soften, complement, or enhance architecture.
Environmental Benefits
Plants alter the environment in which we live by moderating climate,
improving air quality, conserving water, and harboring wildlife. Climate control
is obtained by moderating the effects of sun, wind, and rain. Radiant energy
from the sun is absorbed or deflected by leaves on deciduous plants in the
summer and is only filtered by branches of deciduous plants in winter. We are
cooler when we stand in the shade of plants and are not exposed to direct
sunlight. In winter, we value the sun’s radiant energy. Therefore, we should
plant only small or deciduous plants on the south side of homes.
Wind speed and direction can be affected by plants. The more compact the
foliage on the tree or group of plants, the greater the influence of the
windbreak. The downward fall of rain, sleet, and hail is initially absorbed or
deflected by plants, which provides some protection for people, pets, and
buildings. Plants intercept water, store some of it, and reduce storm runoff
and the possibility of flooding.
Dew and frost are less common under plants because less radiant energy is
released from the soil in those areas at night.
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Temperature in the vicinity of plants is cooler than that away from plants. The
larger the tree, the greater the cooling. By using plants in the cities, we are
able to moderate the heat-island effect caused by pavement and buildings in
commercial areas.
Air quality can be improved through the use of plants, shrubs, and turf.
Leaves filter the air we breathe by removing dust and other particulates. Rain
then washes the pollutants to the ground. Leaves absorb carbon dioxide from
the air to form carbohydrates that are used in the plant’s structure and
function. In this process, leaves also absorb other air pollutants—such as
ozone, carbon monoxide, and sulfur dioxide—and give off oxygen.
By planting plants and shrubs, we return to a more natural, less artificial
environment. Birds and other wildlife are attracted to the area. The natural
cycles of plant growth, reproduction, and decomposition are again present,
both above and below ground. Natural harmony is restored to the urban
environment.
Economic Benefits
70
Individual plants and shrubs have value, but the variability of species, size,
condition, and function makes determining their economic value difficult. The
economic benefits of plants can be both direct and indirect. Direct economic
benefits are usually associated with energy costs. Air-conditioning costs are
lower in a tree-shaded home. Heating costs are reduced when a home has a
windbreak. Plants increase in value from the time they are planted until they
mature. Plants are a wise investment of funds because landscaped homes
are more valuable than no landscaped homes. The savings in energy costs
and the increase in property value directly benefit each home owner.
The indirect economic benefits of plants are even greater. These benefits are
available to the community or region. Lowered electricity bills are paid by
customers when power companies are able to use less water in their cooling
towers, build fewer new facilities to meet peak demands, use reduced
amounts of fossil fuel in their furnaces, and use fewer measures to control air
pollution. Communities also can save money if fewer facilities must be built to
control storm water in the region. To the individual, these savings are small,
but to the community, reductions in these expenses are often in the
thousands of dollars.
1.15.7
Planting the plants
The ideal time to plant plants and shrubs is during the dormant season rain
the fall after leaf drop or early spring before bud break. Weather conditions
are cool and allow plants to establish roots in the new location before spring
rains and summer heat stimulate new top growth.
However, plants properly cared for in the nursery or garden center, and given
the appropriate care during transport to prevent damage, can be planted
throughout the growing season. In tropical and subtropical climates where
plants grow year round, any time is a good time to plant a tree, provided that
sufficient water is available. In either situation, proper handling during planting
is essential to ensure a healthy future for new plants and shrubs. Before you
begin planting your tree, be sure you have had all underground utilities
located prior to digging.
If the tree you are planting is balled or bare root, it is important to understand
that its root system has been reduced by 90 to 95 percent of its original size
during transplanting. As a result of the trauma caused by the digging process,
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plants commonly exhibit what is known as transplant shock. Containerized
plants may also experience transplant shock, particularly if they have circling
roots that must be cut. Transplant shock is indicated by slow growth and
reduced vigor following transplanting. Proper site preparation before and
during planting coupled with good follow-up care reduces the amount of time
the plant experiences transplant shock and allows the tree to quickly establish
in its new location. Carefully follow nine simple steps, and you can
significantly reduce the stress placed on the plant at the time of planting.
1.
Dig a shallow, broad planting hole :
Make the hole wide, as much as three times
the diameter of the root ball but only as deep as the root ball. It is
important to make the hole wide because the roots on the newly
establishing tree must push through surrounding soil in order to establish.
On most planting sites in new developments, the existing soils have been
compacted and are unsuitable for healthy root growth. Breaking up the soil
in a large area around the tree provides the newly emerging roots room to
expand into loose soil to hasten establishment.
2.
Identify the trunk flare :
3.
Remove tree container for containerized plants :
4.
Place the tree at the proper height :
The trunk flare is where the roots spread at the base of
the tree. This point should be partially visible after the tree has been
planted (see diagram). If the trunk flare is not partially visible, you may
have to remove some soil from the top of the root ball. Find it so you can
determine how deep the hole needs to be for proper planting.
Carefully cutting down the sides of
the container may make this easier. Inspect the root ball for circling roots
and cut or remove them. Expose the trunk flare, if necessary.
Before placing the tree in the hole, check to
see that the hole has been dug to the proper depth and no more. The
majority of the roots on the newly planted tree will develop in the top 12
inches of soil. If the tree is planted too deeply, new roots will have difficulty
developing because of a lack of oxygen. It is better to plant the tree a little
high, 2 to 3 inches above the base of the trunk flare, than to plant it at or
below the original growing level. This planting level will allow for some
settling (see diagram). To avoid damage when setting the tree in the hole,
always lift the tree by the root ball and never by the trunk.
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5.
Straighten the tree in the hole :
Before you begin backfilling, have someone view
the tree from several directions to confirm that the tree is straight. Once
you begin backfilling, it is difficult to reposition the tree.
6.
Fill the hole gently but firmly :
Fill the hole about one-third full and gently but
firmly pack the soil around the base of the root ball. Then, if the root ball is
wrapped, cut and remove any fabric, plastic, string, and wire from around
the trunk and root ball to facilitate growth (see diagram). Be careful not to
damage the trunk or roots in the process.
Fill the remainder of the hole, taking care to firmly pack soil to eliminate air
pockets that may cause roots to dry out. To avoid this problem, add the
soil a few inches at a time and settle with water. Continue this process
until the hole is filled and the tree is firmly planted. It is not recommended
to apply fertilizer at the time of planting.
Notes :
a). Write your answer in the space given below.
b). compare your answer with those given at the end of the unit
Que.
3.
What do you understand by green revolution?
4.
What can you do to prevent the pollution?
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…………………………………………………………………………………………
…………………………………………………………………………………………
…………………………………………………………………………………………
…………………………………………………………………………………………
………………………………………………………………………………………..
73
7.
If the tree is grown and dug properly at the nursery,
staking for support will not be necessary in most home landscape
situations. Studies have shown that plants establish more quickly and
develop stronger trunk and root systems if they are not staked at the time
of planting.
Stake the tree, if necessary.
However, protective staking may be required on sites where lawn mower
damage, vandalism, or windy conditions are concerns. If staking is
necessary for support, there are three methods to choose among: staking,
guying, and ball stabilizing. One of the most common methods is staking.
With this method, two stakes used in conjunction with a wide, flexible tie
material on the lower half of the tree will hold the tree upright, provide
flexibility, and minimize injury to the trunk (see diagram). Remove support
staking and ties after the first year of growth.
8.
Mulch is simply organic matter applied to the area at
the base of the tree. It acts as a blanket to hold moisture, it moderates soil
Mulch the base of the tree.
temperature extremes, and it reduces competition from grass and weeds.
Some good choices are leaf litter, pine straw, shredded bark, peat moss,
or composted wood chips. A 2- to 4-inch layer is ideal. More than 4 inches
may cause a problem with oxygen and moisture levels. When placing
mulch, be sure that the actual trunk of the tree is not covered. Doing so
may cause decay of the living bark at the base of the tree. A mulch-free
area, 1 to 2 inches wide at the base of the tree, is sufficient to avoid moist
bark conditions and prevent decay.
9.
Keep the soil moist but not soaked over watering causes
leaves to turn yellow or fall off. Water plants at least once a week, barring
rain, and more frequently during hot weather. When the soil is dry below
the surface of the mulch, it is time to water. Continue until mid-fall, tapering
off for lower temperatures that require less-frequent watering.
Provide follow-up care.
Other follow-up care may include minor pruning of branches damaged
during the planting process. Prune sparingly immediately after planting
and wait to begin necessary corrective pruning until after a full season of
growth in the new location.
74
After above completed these nine simple steps, further routine care and
favorable weather conditions will ensure that your new tree or shrub will
grow and thrive. A valuable asset to any landscape, plants provide a longlasting source of beauty and enjoyment for people of all ages. When
questions arise about the care of your tree, be sure to consult your local
ISA Certified Arborist or a tree care or garden center professional for
assistance.
1.15.8
Plants used as avenue tree for shade
The role of landscape vegetation in conserving energy varies with the different
where enormous amounts of energy are consumed in winter heating; control
of air infiltration is paramount. Hotter southeastern areas place more
emphasis on use of shade to control heat conduction and reduce the need for
summer air-conditioning. Three basic landscape applications which have
proven to save energy are :

The use of shade trees,

Windbreaks, and

The use of foundation plants.
Trees
Trees can reduce summer temperatures significantly. Shading the roof of a
house from the afternoon sun by large trees can reduce temperatures inside
the home by as much as 8 to 10 degrees F.
Deciduous trees provide summer shade, then drop their leaves in the fall. This
allows the warmth of the sun to filter through their bare branches in winter and
helps warm the home. If a home can be situated to take advantage of shade
from existing trees on southeast and west exposures, energy expended to
cool the house can be reduced.
If there are no existing trees, the owner can select and place trees that
ultimately will provide shade. The temptation is to plant the fastest growing
species available. However, this is usually a poor choice for several reasons.
Trees that grow at more moderate rates usually live longer, are less likely to
break in wind and ice storms, and are often more resistant to insects and
diseases.
75
A carefully selected and planted tree with a moderate growth rate often will
respond to good care by increasing its rate of growth. Recommended plants
for India used as shade are given below
Smaller trees can be planted closer to the house and used for shading walls
and window areas. Since they are deciduous, they will provide shade during
the summer and allow light and sun to penetrate during the winter season.
I. Plants used in plantation of shelter belts and wind breaks in
dry, sandy areas
Plant
Botanical name
Babool
Acacia spp.
Ghee quanr
Agave spp.
Siris
Albezia spp.
Dhaura
Annogisus pendula
Sitaphul
Annona squamosa
Neem
Azadirecta indica
Taad
Borasus flebelifer
Palash (Teshu)
Butea monosperma
Casurina
Casurina cristata
Baans
Dendrocalamus strictus
Bargad
Ficus bengalensis
Ratanjot
Jatropha spp.
Subabool
Leucaena lucocephala
Mahua
Madhuca latifolia
Shahtut
Morus alba
Vialayati babool
Parkinsonia aculiata
76
Khajur
Phoenix dactilifera
Anaar
Punica granatum
Imli
Tamarindus indica
Lal jhau
Tamarix dioca
Arjun
Terminalia arjuna
Ber
Ziziphus moritiana
Jharberi
Ziziphus numularia
II. Plants used in plantation of shelter belts and wind breaks on
costal areas
Plant
Botanical name
Kaaju
Anacardium occidentalis
Gulmohar
Cassia siamea
Cassis auriculata
Casurina
Casurina equisitifolia
Gravilea robusta
Aam
Mangifera indica
Karanj
Pongamia glabra
Augstya
Sesbania aegyptica
III. Plants useful for plantation along road sides
A.
On the basis of climate
i) For tropical and subtropical areas
Plant
Botanical name
Kalasiris
A. procera
Babool
Acacia spp.
77
Siris
Albezia spp.
Kadamb
Anthocephalus kadumba
Shisham
Dalbergia latifolia
Eucalyptus
Eucalyptis spp.
Jamun
Eugenia jambolana
Gular udambar
Ficus glomarata
Mahua
Madhuca latifolia
Aam
Mangifera indica
Bakayan
Melia azadirach
Karanj
Pongamia pinnata
Vilyati keekar
Prosopis juliflora
Imli
Tamarindus indica
Arjun
Terminalia arjuna
Jangali badam
Terminalia katappa
ii) For sub-tropical and temperate hilly areas
B.
Plant
Botanical name
Tuna
Cedrilla toona
Deodar
Cedrus deodara
Cupressus
Cupressus samparirens
Gravillia
Gravillia robusta
Akhrot
Juglens rosea
Pinus
Pinus spp.
Populus
Populus spp.
Salix
Salix spp.
For decorative purpose
78
1.15.9
Plant
Botanical name
Rakta chandan
Adenanthera pavonia
Gulabi kachnar
Bauhinia purpuria
Kachnar
Bauhinia variegate
Palash (Teshu)
Butea monosperma
Bottle brush
Calistomon lanciolata
Amaltash
Cassia fistula
Kilvilli
Colviliea racemosa
Gulmohar
Delonix regia
Nili gulmohar
Jacaranda mimosifolia
Karanj
Pongamia pinnata
Ashok
Saraca indica
Plants used for pollution control
Plants
Botanical name
Australian babool
Accasia auriculiformis
Bel
Aegle marmelos
Maharukh
Ailanthus excelsa
Siris
Albizzia lebbeck
Safed siris
Albizzia procera
Kadamb
Anthocephalus kadamba
Katahal
Artocarpus heterophyllus
Neem
Azadiracta indica
Shisham
Dalbergia latifolia
Sissoo
Dalbergia sissoo
Gulmohar
Delonix regia
Baans
Dendrocalamus strictus
79
1.15.10
Tendu
Diosporus melenoxylon
Aonla
Emblica officinalis
Jamun
Eugenia jambolana
Bargad
Ficus bengalensis
Gular udambar
Ficus glomerata
Jangli anjeer
Ficus palmeta
Pipal
Ficus reliogiosa
Gandhraj
Gardenia spp.
Neeli gulmohar
Jacaranda mimosifolia
Pride of India (Dhavra)
Lagerstromea speciosa
Subabool
Leucaena lucocephala
Mahua
Madhuca latifolia
Aam
Mangifera indica
Bakayan
Melia azadirach
Karanj
Pongamia pinnata
Reetha
Sapindus laurifolius
Ashok
Saraca indica
Fountain tree
Spathodia campanulata
Imli
Tamarindus indica
Ber
Ziziphus moritiana
Plants used for aesthetic value
Plants have great aesthetic value. How many of us would be willing to live
without the plants beautifying the world around us? From the forests,
woodlands, and grasslands surrounding our towns and cities to the wildflower
gardens and natural landscaping in backyards, native plants provide a
spiritual link between nature and our Nation's diverse cultural history. Many of
80
the plants grown by gardeners are domesticated versions of wild plants.
Many other gorgeous looking native plants have yet to be chosen for use in
horticultural cultivation.
Plants having beautiful flower
Plants
Botanical name
Plant
height
Flowering time
(in meter)
6-8
March – April
10-12
July – August
Dhanv phansi
Anogeissus pendula
Kadamb
Anthocephalus
kadamba
Gulabi kachnar
Bauhinia purpuria
6-8
November
Kachnar baisakhi
Bauhinia variegata
7-9
February – March
Palash (teshu)
Butea monosperma
4-6
February – March
Bottle brush
Calistomon lanceolatus
7-8
March – April
Amaltash
Cassia fistula
7-8
March – May
Gulabi amaltash
Cassia reinigera
5-6
April – June
Sianis sinna
Cassia siamea
4-5
April – June
Rudraksh
Elaeocarpus spharicus
5-7
March – April
Pangara
Erithrena indica
6-8
March – April
Neeli gulmohar
Jacaranda mimosifolia
8-9
March – May
Bhola
Kleenhovia hospita
4-5
July – August
Pride of India
(Dhavra)
Lagerstromea speciosa
Him champa
Magnolia grandiflora
Nagkesar
Mesua feria
Son-champa
Michelia champaka
8-10
April – May
10-15
April – May
8-10
April – May
8-9
April – May &
September
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Pedina
Mussanda glabrata
Peela gulmohar
Peltophorum enermi
4-5
July – August
12-15
March – May
September November
April – May
Gulmohar
Poinciana regia
7-8
Kanak champa
Pterospermum
acerifolium
8-10
February – May
Ashok
Saraca indica
7-8
February – May
Augstya
Sesbania grandiflora
5-7
December
Fountain tree
Spathodia
campanulata
15-30
February – March
Plants having shaded and beautiful leaves
Plants
Botanical name
Plant
height
Flowering time
(in meter)
Abies
Abies webbiana
Australian babool
Accasia auriculiformis
10
Rakhta chandan
Adenanthera pavonia
6-20
Maharukh
Ailanthus excelsa
Siris
Albizzia lebbeck
Kristmas tree
30-45
10-15
March – April
August
9-16
-
Araucaria excelsa
7-8
-
Neem
Azadiracta indica
8-12
Tad /or bab palm
Borassus flabellifer
12-18
-
Deodar
Cedrus deodara
50-60
-
Kapok
Ceiba petandra
12
April
December –
January
82
Shisham
Dalbergia latifolia
5-10
-
Sissoo
Dalbergia sissoo
6-9
-
Java anjeer
F. bengamina
15-20
-
Rubber
F. elastica
15-20
-
Pakur
F. infectoria
10-12
-
Timla
F. rouxbarghi
3-6
-
Bargad
Ficus bengalensis
20-30
August –
September
Gular udambar
Ficus glomerata
20-30
-
Pipal
Ficus reliogiosa
20-30
-
Karanj
Pongamia pinnata
10-15
April - May
Jeevput
Putranjiva roxburghii
Khajur pankhi
Ravinala
medagascaransis
Chandan
Santalum album
Reetha
Sapindus laurifolius
Mahogoni
Suwietenia mahogoni
6-8
-
10-15
-
7-8
-
8-10
-
15-20
-
1.16 EXTINCTION
In biological world, extinction is the cessation of existence of a species or
group of taxa. The moment of extinction is generally considered the death of
the last individual of that species (although the capacity to breed and recover
may have been lost before this point). Because a species potential range may
be very large, determining this moment is difficult, and is usually done
retrospectively. This difficulty leads to phenomena such as Lazarus taxa,
where a species presumed extinct abruptly "re-appears" (typically in the fossil
record) after a period of apparent absence.
Through evolution, new species arise through the process of speciation —
where new varieties of organisms arise and thrive when they are able to find
83
and exploit an ecological niche — and species become extinct when they are
no longer able to survive in changing conditions or against superior
competition.
A typical species becomes extinct within 10 million years of its first
appearance, although some species, called living fossils, survive virtually
unchanged for hundreds of millions of years. Extinction, though, is usually a
natural phenomenon; it is estimated that 99.9% of all species that have ever
lived are now extinct.
Prior to the dispersion of humans across the earth, extinction generally
occurred at a continuous low rate, mass extinctions being relatively rare
events. Starting approximately 100,000 years ago, and coinciding with an
increase in the numbers and range of humans, species extinctions have
increased to a rate unprecedented since the Cretaceous–Tertiary extinction
event. This is known as the Holocene extinction event and is at least the sixth
such extinction event. Some experts have estimated that up to half of
presently existing species may become extinct by 2100.
1.16.1
Definition
A species becomes extinct when the last existing member of that species
dies. Extinction therefore becomes a certainty when there are no surviving
individuals that are able to reproduce and create a new generation. A species
may become functionally extinct when only a handful of individuals survive,
which are unable to reproduce due to poor health, age, sparse distribution
over a large range, a lack of individuals of both sexes (in sexually reproducing
species), or other reasons.
Bark from the extinct Lepidodendron, which died out after the Carboniferous,
likely due to competition from newer plant life.
Pinpointing the extinction (or pseudoextinction) of a species requires a clear
definition of that species. If it is to be declared extinct, the species in question
must be uniquely identifiable from any ancestor or daughter species, or from
other closely related species. Extinction of a species (or replacement by a
daughter species) plays a key role in the punctuated equilibrium hypothesis of
Stephen Jay Gould and Niles Eldredge.
84
In ecology, extinction is often used informally to refer to local extinction, in
which a species ceases to exist in the chosen area of study, but still exists
elsewhere. This phenomenon is also known as extirpation. Local extinctions
may be followed by a replacement of the species taken from other locations;
wolf reintroduction is an example of this. Species which are not extinct are
termed extant. Those that are extant but threatened by extinction are referred
to as threatened or endangered species.
An important aspect of extinction at the present time are human attempts to
preserve critically endangered species, which is reflected by the creation of
the conservation status "Extinct in the Wild" (EW). Species listed under this
status by the World Conservation Union (IUCN) are not known to have any
living specimens in the wild, and are maintained only in zoos or other artificial
environments. Some of these species are functionally extinct, as they are no
longer part of their natural habitat and it is unlikely the species will ever be
restored to the wild. When possible, modern zoological institutions attempt to
maintain a viable population for species preservation and possible future
reintroduction to the wild through use of carefully planned breeding programs.
The extinction of one species' wild population can have knock-on effects,
causing further extinctions. These are also called "chains of extinction".
1.16.2
Pseudoextinction
Descendants may or may not exist for extinct species. Daughter species that
evolve from a parent species carry on most of the parent species' genetic
information, and even though the parent species may become extinct, the
daughter species lives on. In other cases, species have produced no new
variants, or none that are able to survive the parent species' extinction.
Extinction of a parent species where daughter species or subspecies are still
alive is also called pseudoextinction.
Pseudoextinction is difficult to demonstrate unless one has a strong chain of
evidence linking a living species to members of a pre-existing species. For
example, it is sometimes claimed that the extinct Hyracotherium, which was
an ancient animal similar to the horse, is pseudoextinct, rather than extinct,
because there are several extant species of equus, including zebra and
donkeys.
85
However, as fossil species typically leave no genetic material behind, it is not
possible to say whether Hyracotherium actually evolved into more modern
horse species or simply evolved from a common ancestor with modern
horses. Pseudoextinction is much easier to demonstrate for larger taxonomic
groups. It is said that dinosaurs are pseudoextinct, because some of their
descendants, the birds, survive today.
1.16.3
Causes of Extinction

The passenger pigeon, one of several species of extinct birds, was hunted
to extinction over the course of a few decades.

The Bali Tiger was declared extinct in 1937 due to hunting and habitat
loss.
There are a variety of causes that can contribute directly or indirectly to the
extinction of a species or group of species. "Just as each species is unique,"
write Beverly and Stephen Stearns, "so is each extinction... the causes for
each are varied — some subtle and complex, others obvious and simple".
Most simply, any species that is unable to survive or reproduce in its
environment, and unable to move to a new environment where it can do so,
dies out and becomes extinct.
Extinction of a species may come suddenly when an otherwise healthy
species is wiped out completely, as when toxic pollution renders its entire
habitat unlivable; or may occur gradually over thousands or millions of years,
such as when a species gradually loses out in competition for food to better
adapted competitors.
Assessing the relative importance of genetic factors compared to
environmental ones as the causes of extinction has been compared to the
nature-nurture debate. The question of whether more extinctions in the fossil
record have been caused by evolution or by catastrophe is a subject of
discussion; Mark Newman, the author of Modeling Extinction argues for a
mathematical model that falls between the two positions. By contrast,
conservation biology uses the extinction vortex model to classify extinctions
by cause. When concerns about human extinction have been raised, for
example in Sir Martin Rees' 2003 book Our Final Hour, those concerns lie
with the effects of climate change or technological disaster.
86
Currently, environmental groups and some governments are concerned with
the extinction of species caused by humanity, and are attempting to combat
further extinctions through a variety of conservation programs. Humans can
cause extinction of a species through over harvesting, pollution, habitat
destruction, introduction of new predators and food competitors, over hunting,
and other influences.
According to the World Conservation Union (WCU, also known as IUCN), 784
extinctions have been recorded since the year 1995, the arbitrary date
selected to define "modern" extinctions, with many more likely to have gone
unnoticed.
1.16.4
Genetics and demographic phenomena
Population genetics and demographic phenomena affect the evolution, and
therefore the risk of extinction, of species. Species with small populations are
much more vulnerable to these types of effects. Limited geographic range is
the most important determinant of genus extinction at background rates but
becomes increasingly irrelevant as mass extinction arises.
Natural selection acts to propagate beneficial genetic traits and eliminate
weaknesses. It is nevertheless possible for a deleterious mutation to be
spread throughout a population through the effect of genetic drift.
A diverse or "deep" gene pool gives a population a higher chance of surviving
an adverse change in conditions. Effects that cause or reward a loss in
genetic diversity can increase the chances of extinction of a species.
Population bottlenecks can dramatically reduce genetic diversity by severely
limiting the number of reproducing individuals and make inbreeding more
frequent. The founder effect can cause rapid, individual-based speciation and
is the most dramatic example of a population bottleneck.
Genetic pollution
Purebred naturally evolved region specific wild species can be threatened
with extinction in a big way through the process of Genetic Pollution i.e.
uncontrolled hybridization, introgression and Genetic swaping which leads to
homogenization or replacement of local genotypes as a result of either a
87
numerical and/or fitness advantage of introduced plant or animal. Non-native
species can bring about a form of extinction of native plants and animals by
hybridization and introgression either through purposeful introduction by
humans or through habitat modification, bringing previously isolated species
into contact. These phenomena can be especially detrimental for rare species
coming into contact with more abundant ones where the abundant ones can
interbreed with them swamping the entire rarer gene pool creating hybrids
thus driving the entire original purebred native stock to complete extinction.
Such extinctions are not always apparent from morphological (outward
appearance) observations alone. Some degree of gene flow may be a normal,
evolutionarily constructive process, and all constellations of genes and
genotypes cannot be preserved however, hybridization with or without
introgression may, nevertheless, threaten a rare species' existence.
Widespread genetic pollution also leads to weakening of the naturally evolved
(wild) region specific gene pool leading to weaker hybrid animals and plants
which are not able to cope with natural environs over the long run and fast
tracks them towards final extinction.
The gene pool of a species or a population is the complete set of unique
alleles that would be found by inspecting the genetic material of every living
member of that species or population. A large gene pool indicates extensive
genetic diversity, which is associated with robust populations that can survive
bouts of intense selection. Meanwhile, low genetic diversity (see inbreeding
and population bottlenecks) can cause reduced biological fitness and an
increased chance of extinction amongst the reducing population of purebred
individuals from a species.
Habitat degradation
The degradation of a species' habitat may alter the fitness landscape to such
an extent that the species is no longer able to survive and becomes extinct.
This may occur by direct effects, such as the environment becoming toxic, or
indirectly, by limiting a species' ability to compete effectively for diminished
resources or against new competitor species.
Habitat degradation through toxicity can kill off a species very rapidly, by
killing all living members through contamination or sterilizing them. It can also
88
occur over longer periods at lower toxicity levels by affecting life span,
reproductive capacity, or competitiveness.
Habitat degradation can also take the form of a physical destruction of niche
habitats. The widespread destruction of tropical rainforests and replacement
with open pastureland is widely cited as an example of this; elimination of the
dense forest eliminated the infrastructure needed by many species to survive.
For example, a fern that depends on dense shade for protection from direct
sunlight can no longer survive without forest to shelter it. Another example is
the destruction of ocean floors by bottom trawling.
Diminished resources or introduction of new competitor species also often
accompany habitat degradation. Global warming has allowed some species to
expand their range, bringing unwelcome competition to other species that
previously occupied that area. Sometimes these new competitors are
predators and directly affect prey species, while at other times they may
merely outcompete vulnerable species for limited resources. Vital resources
including water and food can also be limited during habitat degradation,
leading to extinction.
The Golden Toad was last seen on May 15, 1989. Decline in amphibian
populations is ongoing worldwide.
Predation, competition, and disease
Humans have been transporting animals and plants from one part of the world
to another for thousands of years, sometimes deliberately (e.g., livestock
released by sailors onto islands as a source of food) and sometimes
accidentally (e.g., rats escaping from boats). In most cases, such
introductions are unsuccessful, but when they do become established as an
invasive alien species, the consequences can be catastrophic.
Invasive alien species can affect native species directly by eating them,
competing with them, and introducing pathogens or parasites that sicken or
kill them or, indirectly, by destroying or degrading their habitat. Human
populations may themselves act as invasive predators.
According to the "overkill hypothesis", the swift extinction of the megafauna in
areas such as New Zealand, Australia, Madagascar and Hawaii resulted from
89
the sudden introduction of human beings to environments full of animals that
had never seen them before, and were therefore completely unadapted to
their predation techniques.
1.16.5
Co-extinction
Co-extinction refers to the loss of a species due to the extinction of another;
for example, the extinction of parasitic insects following the loss of their hosts.
Co-extinction can also occur when a species loses its pollinator, or to
predators in a food chain who lose their prey. "Species co-extinction is a
manifestation of the interconnectedness of organisms in complex ecosystems.
While co-extinction may not be the most important cause of species
extinctions, it is certainly an insidious one".
1.17 ENVIRONMENTAL STATUS OF PLANTS BASED ON
IUCN
Plants are a vital part of the world’s biological diversity and an essential
resource for human well-being. Besides the crop plants that provide our basic
food and fibres, many thousands of wild plants have great economic and
cultural importance and potential, providing food, medicine, fuel, clothing and
shelter for vast numbers of people throughout the world. Traditional Chinese
medicine alone uses over 5,000 plant species and traditional medicines in
India are based on 7,000 different plants.
Plants play a key role in maintaining basic ecosystem functions and are
essential for the survival of the world's animal life. Yet, despite our reliance on
plants, crisis point has been reached. Although much work remains to be
carried out to evaluate the status of the world’s plants, it is clear that between
60,000 to 100,000 plant species are threatened worldwide.
Plants are endangered by a combination of factors :
1. Over-collecting,
2. Unsustainable agriculture and forestry practices,
3. Urbanisation,
4. Pollution,
5. Land use changes, and
90
6. The spread of invasive alien species and climate change.
Assessing the conservation status of plants in the wild is a vital component of
biodiversity conservation planning. Since 1963 when Sir Peter Scott first
established the Red Listing system, the International Union for Conservation
of Nature (also known as World Conservation Union) Red List Categories has
been widely acknowledged as the international standard for species
conservation assessment.
Initially a set of five categories of threat was adopted :
1.
Endangered,
2.
Vulnerable,
3.
Rare,
4.
Indeterminate, and
5.
Not Threatened.
These were in use until replaced in 1994 by a new objective system of
categorisation which, in a modified form, remains the IUCN Red List system in
use today.
IUCN cautions that the category of threat applied to a species using the Red
List system does not in itself determine priorities for action. It suggests that
other factors such as costs, logistics, and chances of success and other
biological characteristics of the species need to be taken into account (IUCN,
2001). Degree of threat does however clearly have a significant impact in
prioritisation of species for conservation action and the process of applying
the categories and criteria helps to define the conservation action required. If
the species is identified as Endangered due to restricted range and declining
and fragmented habitat, for example, habitat conservation and restoration
may be inferred as an appropriate response. If the species is endangered due
to population decline caused by levels of exploitation, management of
harvesting should be considered as at least part of the solution.
In addition to helping to define species conservation actions, Red List
information supports various assessments of the state of ecosystems
worldwide. It is used to help identify Biodiversity Hotspots as defined by
Conservation International; Important Plant Areas, as defined by Plant life
International and was used in the Millennium Ecosystem Assessment. Red list
91
information is also used to define High Conservation Value forests, initially
defined by the Forest Stewardship Council and red list information specifically
for tree species is used in the FAO Global Forest Resources Assessment.
Target 2 of the Global Strategy for Plant Conservation (GSPC) calls for a
preliminary assessment of the conservation status of all known plant species
at national, regional and international levels. This target is very important as a
baseline for implementation of other GSPC targets relating for example to in
situ and ex situ conservation of plant species. IUCN is the lead facilitating
agency for Target 2.
At present there are 8,447 plant species recorded as threatened in the 2007
IUCN Red List. Progress in red listing for plants is widely acknowledged to be
unimpressive. Problems include the perception that the current IUCN Red List
categories and criteria are complicated and difficult to apply; the requirement
for relatively extensive supporting documentation; and lack of motivation when
many countries have their own national red lists using different categories of
threat. In response to the shortfall in data collection, IUCN has developed
RapidList to speed up preliminary assessments and this provides an effective
way to contribute to GSPC Target 2.
Full red listing remains the preferred option for many experts involved in Red
Listing particularly where some leeway in the level of supporting
documentation is allowed. Currently 5,643 of the plants included as
threatened in the 2007 IUCN Red List are tree species many of which were
recorded at a time when the documentation requirements were more relaxed.
Of these 1,002 tree species are Critically Endangered. Various approaches to
tree red listing are ongoing as described further below and the momentum is
increasing using a pragmatic approach to the use of the IUCN Red List
Categories and Criteria. It is vital that we speed up this process so that tree
conservation receives the attention it deserves.
In the early days plant red listing was coordinated by the IUCN/Species
Survival Commission (SSC) Threatened Plant Specialist Group with a
Secretariat based at Kew. As lists of threatened plants were compiled they
were sent to botanic gardens to find out where species were in cultivation.
Data received were stored in a central database. The role of collating
information on threatened plants in ex situ collections was subsequently taken
on and developed by BGCI. Now of course botanic gardens and arboreta can
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enter their collection data online to BGCI’s online Plant Search database
(www.bgci.org/plantsearch) and compare this with information in the IUCN
Red List.
Over time IUCN/ SSC established a range of Specialist Groups to undertake
red listing and action planning for plant species. Currently there are 28 such
groups involved to a varying extent in these processes. Undertaking red list
assessments for plants is a dispersed activity undertaken by individual
IUCN/SSC Specialist Groups and also various botanical institutions such as
Fairchild Tropical Botanic Garden; Missouri Botanical Garden; Royal Botanic
Gardens, Kew and the Smithsonian Institution. Data are collated by the IUCN
Species Programme which is based in Cambridge, UK.
The IUCN/SSC Global Tree Specialist Group has been actively involved in
undertaking assessments of the conservation status of tree species since its
establishment in 2003. The Secretariat of the Group is now hosted by BGCI
providing a direct link between the collection of data on species in the wild
and their status in ex situ collections. The advantage of such a link is that
BGCI and its members can help to select priority groups of trees (for example
those of ornamental as well as ecological value) to be assessed using the
IUCN categories and criteria, can help with the assessments and directly
utilise the resulting data in conservation planning. In addition to promoting and
implementing red listing, the second function of the Global Tree Specialist
Group is to provide advice to the Global Trees Campaign, an initiative
established by the UNEP World Conservation Monitoring Centre (UNEPWCMC) and Fauna & Flora International (FFI). The Global Trees Campaign is
now being re-developed as a joint initiative by FFI and BGCI with input from
UNEP-WCMC on a project basis.
The Global Tree Specialist Group (GTSG) has undertaken a range of regional
tree red list assessments for Ethiopia and Eritrea, the Caucasus, Central Asia,
Guatemala, dry forest trees of Central America, cloud forests of Mexico and
has worked with the Cuban Plant Specialist Group on an assessment of the
trees of Cuba. Workshops were held as part of the assessment process in
each case (except for Ethiopia and Eritrea) and the workshops were also
used to assess priorities for conservation action through the Global Trees
Campaign. Current projects resulting from the workshops include a detailed
survey of nine threatened Pyrus species in the Caucasus involving experts
from Armenia, Azerbaijan and Georgia. Another project is underway in
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Krgyzstan on the conservation needs of two of the most threatened apple
species in the country, Malus niedzwetzkyana and Malus sieversii.
In parallel with the regional tree conservation assessments, the Global Tree
Specialist Group has also undertaken global evaluations of the conservation
status of selected genera: Magnolia, Quercus and Acer and has started
working on Diospyros and Rhododendron. Workshops to assess the
conservation status of species are also used to define priorities for
conservation action. The Red List of Magnoliaceae was published in April
2007 following an extensive datagathering and consultation exercise. The
Red List identifies 131 species of Magnoliaceae as threatened – over half the
known taxa in the family. Of these, 89 are listed as Critically Endangered and
Endangered.
BGCI is now undertaking a comprehensive survey of ex situ collections of
Magnolias as a basis for planning restoration action for Critically Endangered
and Endangered species. So far we have received information from 181
gardens and this is being compiled in BGCI’s PlantSearch database. More
detailed information is being requested on the Magnoliaceae species held in
the collections, including data on the origin and verification of material, related
conservation and recovery programmes, methods of and expertise in
cultivation and propagation. In 2008 we will move ahead with planning
workshops in China, the Caribbean and Colombia to maximise the potential
for on the ground conservation action.
Global Trees Campaign projects have already been undertaken for five target
Magnolia spp. identified as priorities at a Magnolia red listing workshop held in
Kunming, China in 2004. One project, for example, currently being undertaken
by the Kunming Botanic Garden working with FFI is reinforcing the wild
population of M. sinica, reduced to just 10 individuals in the wild, with saplings
found in various nurseries during project surveys.
The Red List of Oaks has recently been published. The assessment includes
207 species leaving around 300 for future evaluations. 29 species are
currently considered to be Critically Endangered or Endangered. A BGCI
survey of ex situ collections will take place shortly using the same approach
as taken for Magnolias. Then priority restoration activities will be planned.
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Notes :
a). Write your answer in the space given below.
b). compare your answer with those given at the end of the unit
Que.
5.
Define causes of extinction and pseudoextinction.
6.
What is the threat categories of IUCN?
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Recently a highly successful workshop was held at the University of British
Colombia Botanical Garden and Centre for Plant Research in Vancouver to
review the conservation status of Acer spp. in the wild and to assess priorities
for conservation action. A complete assessment of the Acer genus was
undertaken with 19 species categorized as Critically Endangered or
Endangered. At the workshop priorities for immediate action were highlighted
for six Chinese species which are Critically Endangered and in need of
immediate conservation attention. One such species is Acer pentaphyllum.
Although safe in cultivation, the fate of wild populations of this species is
extremely precarious. Another Critically Endangered species is A. yangbiense
which is currently known from less than ten individuals in an area of mixed
forest, close to agricultural land in the province of Yunnan. Ex situ
conservation is the only hope for saving this species, at least in the short
term.
A regional workshop to assess the conservation status of Diospyros and
palms in SE Asia was organized by BGCI and hosted by the College of
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Forestry, University of the Philippines, Los Baños in June, 2007. Nineteen
participants from throughout the region attended and began the process of
entering data on palms and ebonies into the Data Entry Module of IUCN’s
Species Information Service (SIS). Dr Scot Zona from Fairchild Tropical
Botanic Garden and Chair of the Palm Specialist Group provided training in
the application of IUCN Red List Categories and Criteria. It was agreed that
by the end of 2007, the conservation status of all endemic palms in the region
should be assessed and a regional checklist of ebonies compiled. The ebony
work will feed into a global evaluation of the genus.
BGCI also plans to assess the conservation status of Rhododendron species
as a basis for prioritising conservation action for globally threatened species
within the genus. There are over 800 species of Rhododendron occurring in
the wild extending from Europe to Papua New Guinea with one species in
Australia. Only 11 species are currently included in the IUCN Red List but
many more species are known to be under threat in the wild. BGCI plans to
work closely with the Royal Botanic Garden, Edinburgh (RBGE) in
undertaking this project. Marion Mackay a member of the GTSG based at the
Institute of Natural Resources, Massey University, New Zealand and her
research student Ahmed Fayaz, are currently helping with an initial literature
review. A preliminary list of candidate threatened species will be presented at
the International Rhododendron Conference to be held at RBGE in May 2008.
Information on the conservation status of individual tree species is valuable
for conserving both the species and for supporting habitat conservation. As
the species assessments continue, the true scale of the threats to wild plants
becomes apparent. Efforts at restoration will become increasingly important
as will translocation to new sites in response to global climate change. GSPC
Target 8 calls for 10 percent of Critically endangered species to be in
restoration programmes by 2010. Can we achieve this goal for trees?
1.17.1
The Global Strategy for Plant Conservation
The Convention on Biological Diversity (CBD) Global Strategy for Plant
Conservation was adopted on 19 April 2002 by the 6th CBD Conference of
the Parties. The IUCN/ SSC Plant Conservation Committee is committed to
helping achieve the targets of this Global Strategy (2002-2010), while
continuing to use the five year IUCN/ SSC Plant Conservation Strategy as the
basis for the Plants Programme's work.
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Decision VI/9
The Conference of the Parties:

Adopts the Global Strategy for Plant Conservation, including outcomeoriented global targets for 2010, annexed to the present decision;

Invites relevant international and regional organizations to endorse the
strategy and to contribute to its implementation, including to adopt these
targets, in order to promote a common effort towards halting the loss of
plant diversity;

Emphasizes that the targets should be viewed as a flexible framework
within which national and/or regional targets may be developed, according
to national priorities and capacities, and taking into account differences in
plant diversity between countries;

Invites Parties and Governments to develop national and/or regional
targets, and, as appropriate, to incorporate them into relevant plans,
programmes and initiatives, including national biodiversity strategies and
action plans;

Stresses the potential role of the strategy in contributing to poverty
alleviation and sustainable development;

Emphasizes the need for capacity-building, particularly in developing
countries, small island developing States, and countries with economies in
transition, in order to enable them to implement the strategy;

Invites Parties, other Governments, the financial mechanism, and funding
organizations to provide adequate and timely support to the
implementation of the strategy, especially by developing country Parties, in
particular the least developed countries and small island developing States
among them, and Parties with economies in transition;

Decides to review, at its eighth and tenth meetings, the progress made in
reaching the global targets, and provide additional guidance in light of
those reviews, including, as necessary, refinement of the targets;

Decides to consider the Global Strategy for Plant Conservation as a pilot
approach for the use of outcome targets under the Convention within the
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context of the Strategic Plan and, also consider the wider application of
this approach to other areas under the Convention, including other
taxonomic groups;


Requests the Subsidiary Body on Scientific, Technical and Technological
Advice:
o
To take the targets into consideration in its periodic reviews of the
thematic and cross-cutting programmes of work of the Convention;
o
To develop ways and means, within the Convention's thematic and
cross-cutting programmes of work, for promoting implementation of the
global strategy for plant conservation, and for monitoring and
assessing progress; and to report to the Conference of the Parties at
its seventh meeting;
Welcomes the contribution of the "Gran Canaria Group" in developing this
Strategy, and invite the organizations involved, and other relevant
organizations, in collaboration with the Executive Secretary, to contribute
to the further development, implementation and monitoring of the Strategy.
1.18 LET US SUM UP
After going through this unit, you would have achieved the objectives stated earlier in the unit. Let us
recall what we have discussed so far.
1. The Green Revolution was a technology package comprising material
components of improved high yielding varieties of two staple cereals (rice
and wheat), irrigation or controlled water supply and improved moisture
utilization, fertilizers, and pesticides, and associated management skills.
2. The Green Revolution resulted in a record grain output of 131 million
tonnes in 1978/79. This established India as one of the world's biggest
agricultural producers. Yield per unit of farmland improved by more than
30% between1947 (when India gained political independence) and 1979.
The crop area under high yielding varieties of wheat and rice grew
considerably during the Green Revolution.
3. The Green Revolution also created plenty of jobs not only for agricultural
workers but also industrial workers by the creation of related facilities such
as factories and hydroelectric power stations.
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4.
Crop yields have kept pace with rapidly expanding global population and production demands
during the past half century as a result of genetic research, new technologies and improved farming
practices.
5.
Advanced plant breeding, biotechnology and other innovations hold potential to continue the
impressive productivity gains that farmers have demonstrated by delivering more bushels per acres
with reduced water and fertilizer resources per unit of production.
6.
Improvements in technology and breeding hold promise to improve grain quality as well as quantity.
By producing wholesome, disease-resistant grain, farmers experience reduced levels of grain
damage and waste in the harvesting, handling, transportation and storage processes used in
modern grain production.
7. A critical component of continued yield increases is to maximize the
productivity of each acre (i.e. choosing products and practices to match
varying soil conditions within individual fields.)
8. High quality grain, when combined with new, more efficient biofuels
production technologies can maximize the energy output per acre and
provide valuable feed co products to support a healthy livestock industry.
9.
Plants have great aesthetic value. From the forests, woodlands, and grasslands surrounding our
towns and cities to the wildflower gardens and natural landscaping in backyards, native plants
provide a spiritual link between nature and our Nation's diverse cultural history. Many of the plants
grown by gardeners are domesticated versions of wild plants.
10. Number of factors like misuse of nature, destruction and degradation of forests and habitats,
contamination and destruction of natural resources is leading to the extinction of several species of
organisms.
1.19 CHECK YOUR PROGRESS : THE KEY
2.
Your answer may be as follows :
i) The Green Revolution a technology package comprising material
components of improved high yielding varieties of two staple cereals
(rice and wheat), irrigation or controlled water supply and improved
moisture utilization, fertilizers, and pesticides, and associated
management skills.
ii) Plantation pollution indicator plants, reduce the level of contaminant
and pollutant in the environment.
iii) Any species that is unable to survive or reproduce in its environment,
and unable to move to a new environment where it can do so, dies out
and becomes extinct.
iv) The threat categories of IUCN are endangered, vulnerable, rare,
indeterminate, and not threatened.
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1.20 ASSIGNMENTS/ ACTIVITIES
It is compulsory for every student to complete an assignment/ activity/ project
work from any known prospects of this unit. Explain the following (any one):
1.
Green revolution in India and its consequences.
2.
Pollution indicator plants and their plantation methods.
3.
Principal of conservation
4.
IUCN categories of threat
5.
Extinction of species.
6.
Pseudoextinction
7.
World food demands
1.21 REFERENCES / FURTHER READINGS
Bradshaw A. 1995. Trees in the Urban Landscape : Principles & Practice, E & FN
Spon/ Chapman & Hall.
Hazell P and Haddad L. 2001. Agricultural Research and Poverty Reduction, 2020
Vision Discussion Paper 34. International Food Policy Research Institute,
Washington DC.
Hazell P and Ramasamy C. 1991. The Green Revolution Reconsidered : The Impact
of High-yielding Rice Varieties in South India, John Hopkins University Press
for International Food Policy Research Institute (IFPRI), Baltimore, Md, USA.
Heisey, P.W., M.A. Lantican and H.J. Dubin. 2002. Impacts of international wheat
breeding research in developing countries. 1966–97. Mexico, D.F.: CIMMYT,
73 p.
Hugh P P. (2002). "Limits to the use of threatened species lists". Trends in Ecology &
Evolution 17 (11): 503–507.
IUCN. 2001. Red List categories and criteria. Version 3.1. IUCN Species Survival
Commission, Gland, Switzerland.
Jain, K.B.L. 1994. Wheat cultivars in India (Compiled). Directorate of Wheat
Research, Karnal 132001, India. Research Bulletin No. 2: 66 p.
Lipton M, and Longhurst R. 1989. New Seeds and Poor People, Johns Hopkins
University Press, Baltimore, Md, USA.
Mosley P. 2003. A Painful Ascent : The Green Revolution in Africa, Rutledge,
London.
N. Mrosovsky (1997). "IUCN's credibility critically endangered". Nature 389: 436.
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Nagarajan, S. 2000. Thought for the new millennium. Wheat production in India – a
success story and future strategies. Indian Farming. 50: 9-16.
Nagarajan, S. and D. Mohan. 1994. Shortage to surplus – Sustaining the wheat
revolution in India through coordinated research. Directorate of Wheat
Research, Karnal 132001, India. Research Bulletin. 1: 20 p.
Nagarajan, S., R.P. Singh, Randhir Singh, Satyavir Singh, Ajmer Singh, Anuj Kumar
and Ramesh Chand. 2001. Transfer of technologies in wheat through frontline
demonstrations in India – A comprehensive report 1995 – 2000. Directorate of
Wheat Research, Karnal 132001, India, No. 6: 21 p.
Rosegrant M, and Hazell P. 2000. Transforming the Rural Asian Economy : The
Unfinished Revolution, Oxford University Press for the Asian Development
Bank, Hong Kong.
Sankaram, A. 1992. Food and Nutrition Security for developing world. Indian
Farming. 42: 3-10.
Swaminathan, M.S. 1978. The Indian Farming. Special issue. February 1978.
27(11): 2–53.
Swaminathan, M.S. 1993. Wheat revolution – a dialogue (Edited). The MacMillan
India Ltd. Madras. 164 p.
Tribe D. 1994. Feeding and Greening the World : The Role of International
Agricultural Research, CAB International, Wallingford, UK.
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