CHAPTER TWO
LITERATURE REVIEW
3.1 Preview
The literature review for this project work has four (5) subheadings:
i.
Economic importance of maize
ii. Maize diseases
iii. Pests of maize
iv. Control of pest and diseases of maize
and
v.
Some effects chemicals used in pest and disease control on humans.
3.2 Economic importance of maize
Maize is a very important crop cultivated in Ghana. It is utilized mainly for human
consumption and form about 50% to 70% of the constituents of livestock feed. Tons
of million are produced annually but an appreciated quantity is imported annually to
supplement the local reduction due to pts demand. Maize is a staple food and is
sometimes grown on a garden scale where it cannot be grown as a farm crop
(Anyanwu, 1979). It is an important source of carbohydrate and if eaten in the
matured state, it provides useful quantities of vitamins C. The yellow grain varieties
have vitamin A. It is a source of income and maize leaves and stalks contain about
30% of the total nutrients in corn plants; hence it is used as animal feed - pasture.
Some maize are cut and fed green to livestock. Maize occupies a central position in
having a meaningful, workable and effective food security system in any society.
The dietary importance of maize in the diet of Ghanaian hence the people of Buem
cannot be overemphasized; maize, millet, sorghum, rice and other cereals account
for about 70% of the total caloric intake in most Ghanaian communities. The dietary
importance of cereals and legumes is increased by the fact that they complement one
another. Legumes generally have a high content of lysine, which together with
tryptophan tends to be limiting in cereals. On the other hand, cereals are relatively
rich in methadone that tends to be limiting in legumes (Aworh, 1999). Consequently,
maize and beans provide a better nutrition when eaten together than separately. It is
hoped that exploring students understanding of maize crop management and pest
control strategies would help them to adopt or adapt the best attitudes that promote
production of maize crop.
3.3 Diseases of maize
This popular booklet, already in its fourth edition, is designed as a quick guide for
identifying maize diseases. Based on previous editions produced by maize
pathologist
Carlos De Leon, the new work has been updated by contributions from maize
pathologist Dan Jeffers. It is intended for field use by agricultural technicians and
maize producers, and the taxonomic short forms of the various pathogens are
deemed to be appropriate and adequate. For fungal pathogens, both the sexual
(teleomorph) and asexual (anamorph) names of the fungi are often included. Several
modifications in naming systems have been made since the last edition.
Common names of the diseases are designated mostly following the naming systems
described by (Ullstrup 1985).
Maize stem borer lives in soil, and feeds on the roots, which caused death. White
grub: It initially feeds leaves, and finally enters inside stalk and damages it by eating
the growing shoot and flesh inside. Black smut Source: Pythium Stalk/Stem rot
disease. Black smut (Fungal disease) the tassels of the maize plant become black and
rot. The cob is filled with blackish powdery dusts in place of kernels.
Pythium (Bacterial disease) Blackening of stalk near about second node from soil
surface, the stem rots, and stalk collapses. The stalk with water-soaked releases
offensive smell. The cob is filled with blackish powdery dusts in place of kernels.
(Bacterial disease) Blackening of stalk near about second de from soil surface, the
stem rots, and stalk collapses.
Other disastrous pests
Literature, Agricultural Field Officers and maize farmers identified the following as
potential field pest that reduce maize production:
i.
Birds especially weaver birds ii.
Insects at the maggot and
stage especially army worms and beetles. iii.
Rodents like
mouse, rats grasscutter.
3.4 Control of pest and diseases of maize.
Major causes of disease and pest attack in a study lead by (Mozumdar, 2014) includes;
•
Use of not well-decomposed FYM.
•
Residues of previous crops.
•
Lack of proper cleaning of the field.
•
The fungal disease like Downey mildew can attack, if the temperature and humidity
is high.
To control these situations some of the following practices should be adopted:
•
Do not use unfermented FYM. Use the chemical hamal, in case, there is the
prevalence of white grub every year. Use 2 kg of meterhizium pesticide per ropani
mixing with soil during second plowing time.
•
If there is highly grub, we also can use M at second weeding time in s It initially
feeds leaves, and finally enters inside stalk and damages it eating the growing shoot
and flesh.
Remove the borer infected maize plant from the field, and can also be fed to the
animal. Use carbofuran pesticide 4 granules per plant placing them at tassel growing
part of maize at knee-height stage. Control methods Plowing the field, and destroy it
picking up the white grub manually
•
Early sowing of maize result in the formation of cob before heavy rainfall start,
which can control this disease.
•
Make good drainage facility in the field (Fungal disease) The tassels become black
and rot. The cob is filled with blackish powdery dusts in place of grains.
•
If black smut disease maize field, wrap it with polyethene bag without dropping on
field, chop the stalk and burry it or burn it down. (Bacterial disease) Blackening of
stalk near about second de from soil surface, the stem rots, and stalk collapses. The
stalk with water-soaked releases
•
Early sowing of maize results in the formation of cob before heavy rainfall start
Carbofuran (Furadan 3%) is used to control the stem borers.
Other different types of pesticides are in use to control disease and pest. Bio
pesticides of different types are available and are in use to control disease and pest.
The advantages of Bio pesticides / Botanical pesticides are that they are environment
friendly and provide sustainable method of crop conservation.
3.5 Some effects chemicals used in pest and disease control on humans.
Heavy use of toxic pesticides in agriculture worldwide has raised serious concerns
about health issues. The World Health Organization (WHO, 2015) estimates that
acute pesticide poisoning (APP) affects 3 million people and accounts for 20,000
unintentional deaths per year, with 99 percent of these fatalities believed to be in
developing countries.
Several diseases related to pesticide poisonings have been reported worldwide.
Farmers misuse pesticides and do not follow safety procedures for application
despite being informed about negative health effects of these products.
Consequently, both acute and chronic cases of pesticide-induced illness are common
in maize producing areas. Research projects have been conducted by many
researchers to examine the perception, knowledge and practices associated with the
use of pesticides in especially rural areas where most of the farmers are illiterates, as
well as the awareness of farmworkers with regard to the possible side effects of
these chemicals on human health (los países del Istmo Centroamericano 2001).
Poisoning incidences in agriculture occur even more often as a result of careless
handling of pesticides usually on the part of operator error due to willful negligence,
lack of information or lack of training (Koh and Jeyaratnam 1996; Reeves & Schafer
2003). For example, leakages from joints in the application equipment may often
cause farmers to come into direct skin contact with large amounts of a pesticide.
Similarly, clogged or unsuitable nozzles on the spraying equipment affect the quality
of application and
increase the degree of exposure.
Changes in the wind speed and direction during spraying can result in pesticide
absorption in the respiratory tract. Application on extremely hot and dry days
promotes pesticide drift which also increases exposure. Spraying from the air can
create a risk for farmers who are not involved in the operation, including the
population at large. All the above situations – which are common during pesticide
application – may result in direct and prolonged exposure of farmers to pesticides
which may in turn affect their health