Chapter 12: Improvement in Food Resources - Questions and Answers

Cereals provide carbohydrates for energy requirement. Pulses provide proteins. Fruits and vegetables provide a range of vitamins and minerals in addition to small amounts of proteins, carbohydrates and fats.

Biotic factors affecting crop production:

• Pests: Insects, mites, and other organisms that feed on crops
• Diseases: Fungal, bacterial, and viral infections
• Weeds: Compete with crops for nutrients, water, and sunlight
• Beneficial organisms: Earthworms, pollinators, and nitrogen-fixing bacteria

Abiotic factors affecting crop production:

• Temperature: Affects germination, growth, and reproduction
• Water availability: Essential for photosynthesis and nutrient transport
• Soil quality: Nutrient content, pH, and texture
• Sunlight: Required for photosynthesis
• Wind: Can cause physical damage and affect pollination
• Natural disasters: Droughts, floods, and storms

Desirable agronomic characteristics for crop improvement:

• High yield: Increased production per unit area
• Disease resistance: Ability to withstand common pathogens
• Pest resistance: Natural defense against insects and pests
• Drought tolerance: Ability to grow with limited water
• Short maturity duration: Faster growth and harvest cycles
• Wider adaptability: Ability to grow in different climatic conditions
• Responsive to fertilizers: Efficient use of applied nutrients
• Better quality: Improved nutritional value and taste
• Lodging resistance: Strong stems that don't bend or break
• Uniform ripening: Consistent maturity for easier harvesting

Macro-nutrients are nutrients which are required by plants in large quantities. They are called macro-nutrients because plants need them in larger amounts compared to micro-nutrients. The macro-nutrients include nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.

Plants get nutrients from air, water and soil. Air supplies carbon and oxygen, water supplies hydrogen and oxygen, and soil supplies the other thirteen nutrients including macro-nutrients and micro-nutrients.

Manure contains large quantities of organic matter and supplies small quantities of nutrients to the soil. It helps in enriching soil with nutrients and organic matter, improving soil structure, increasing water holding capacity in sandy soils, and helping drainage in clayey soils. Manure is prepared by decomposition of animal excreta and plant waste.

Fertilizers are commercially produced plant nutrients that supply nitrogen, phosphorus and potassium. They ensure good vegetative growth but continuous use can destroy soil fertility because organic matter is not replenished and micro-organisms are harmed. Fertilizers provide short-term benefits while manure provides long-term benefits for maintaining soil fertility.

Option (c) will give the most benefits because it includes all the important practices for high crop yield: quality seeds, irrigation, fertilizers, and crop protection measures. Using only high-quality seeds without irrigation and fertilizers (option a) or using ordinary seeds with irrigation and fertilizers (option b) would not give optimal results. The combination of all good practices ensures maximum yield.

Preventive measures and biological control methods should be preferred because they are environmentally friendly and sustainable. Excessive use of pesticides creates problems as they can be poisonous to many plant and animal species and cause environmental pollution. Preventive methods such as proper seed bed preparation, timely sowing of crops, intercropping and crop rotation help in weed and pest control without harmful chemicals. Biological control is part of organic farming which maintains ecological balance.

Factors responsible for losses of grains during storage are:

• Biotic factors: Insects, rodents, fungi, mites and bacteria
• Abiotic factors: Inappropriate moisture and temperatures in the place of storage

These factors cause degradation in quality, loss in weight, poor germinability, discolouration of produce, all leading to poor marketability.

Cross-breeding is commonly used for improving cattle breeds. This method involves crossing Indian breeds (which show excellent resistance to diseases) with exotic or foreign breeds (which are selected for long lactation periods and high milk yield). Cross-breeding helps to get animals with both the desired qualities - disease resistance and high milk production.

This statement implies that poultry birds can efficiently convert agricultural by-products and low-fiber food materials that are not suitable for human consumption into high-quality protein in the form of eggs and meat. This makes poultry farming an efficient and economical way to produce nutritious food, as it utilizes waste products and by-products that would otherwise go unused, converting them into valuable animal protein.

Common management practices in dairy and poultry farming include:

• Proper cleaning and shelter facilities
• Regular brushing/grooming to remove dirt and loose hair
• Provision of balanced rations containing all necessary nutrients
• Disease control through vaccinations and proper sanitation
• Proper ventilation in housing
• Maintenance of hygienic conditions

Broilers:

• Chicken raised for meat production
• Fed with protein-rich ration with adequate fat
• Require conditions for fast growth and good feed efficiency
• Need care to avoid mortality and maintain feathering and carcass quality

Layers:

• Chicken raised for egg production
• Different nutritional requirements focused on egg production
• Management focused on maximizing egg production
• May have different housing and environmental requirements

Fish are obtained in two ways:

1. Capture fishing: Obtaining fish from natural resources like oceans, rivers, and lakes
2. Culture fishery: Fish farming where fish are bred and raised in controlled environments like ponds

Advantages of composite fish culture include:

• Multiple fish species with different food habits are grown together
• Food available in all parts of the pond is utilized without competition
• Increases the fish yield from the pond
• Species are selected so they don't compete for food
• Examples: Catlas (surface feeders), Rohus (middle-zone feeders), Mrigals and Common Carps (bottom feeders), Grass Carps (weed feeders)

Desirable characters of bee varieties suitable for honey production include:

• High honey collection capacity
• Less stinging tendency
• Staying in a given beehive for long periods
• Good breeding capacity
• Example: Italian bees (Apis mellifera) have these desirable characters

Pasturage refers to the flowers available to the bees for nectar and pollen collection. The value or quality of honey depends upon the pasturage. In addition to adequate quantity of pasturage, the kind of flowers available will determine the taste of the honey. Different flowers produce honey with different flavors, colors, and nutritional properties.