Notes for Improvement in Food Resources
Crop Variety Improvement
In this approach, crops are selected on the basis of their characteristics. For instance,
how well they can respond to fertilizers, can they produce high yield, how they resist
diseases and so on.
Different methods of Crop Variety Improvement
1. Hybridisation - In this process, genetically different plants are
crossbred.They can be three types of crossing:
•
•
•
Intervarietal - Between two varieties of a plant
Interspecific - Between two species belonging to same genus
Inter Generic - Between species of different genus
2. Introduction of Gene - A gene that can provide the desirable characteristics
to acrop are introduced in this process. As a result, we obtain genetically
modified crops.
Why do we need to perform a crop variety improvement?
a. Improved Quality: Should give more nutrients like carbohydrates,
proteinsetc.
b. Biotic Resistance: Resistance to diseases due to living micro –
organisms,insects.
c. Abiotic Resistance: Resistance to problems due to non – living
things like drought, heat, heat, cold, frost, water logging, salinity
(excess salt).
d. Less Maturity Duration: Short duration crops require less
costing andmore rounds of crop.
e. Wider Adaptability: Crops which can grow in different conditions,
willhelp in setting high production.
f. Desired Agronomic Traits: Crops which contain desired agronomic
traits(height, branching, leafs), sets high production.
How are fertilizers and manure different?
Manure
Fertilizers
Manure provides humus to the
Fertilizers do not provide humus
soil
to the soil
Manures are less rich in nutrients Fertilizers are highly rich in
nutrients
Long term usage of manure leads Long term usage of fertilizers
to increment inthe fertility of the can lead todecrease in the soil
soil
fertility
What is organic farming?
A farming practice which involves no use of artificial chemicals, fertilizers and
pesticides and completely relies upon organic matter is known as organic farming.
Organic farming uses healthy cropping systems such as crop rotation, intercropping
and mixed cropping. Organic matter used in organic farming:
•
manure
•
bioagents such as blue-green algae
•
biofertilizers
•
Neem leaves and turmeric as biopesticides
Disadvantages of using pesticides:
• Pollution
•
Toxic to many useful plants and animals.
Weed Control
Weed Control involve precautionary measures to avoid weed growth, which can be
done by:
• Manual removal of weeds.
• Seed bed preparation: Fields are ploughed deep. Thus weed seeds come on
top and germinate in few days. Then they can be removed before planting
actual crops.
•
Crop Rotation: Some crops destroy weeds in fields. Such crops included in
crop rotation.
•
Proper Sowing Time: Warm and humid climate not favourable.
•
Inter Cropping: Due to presence of multiple crops, environmental
resources are used more efficiently. Thus very little resources are left for
growth of weeds..