Class IX Science (Biology) Improvement in Food...

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Class IX – Science (Biology) Improvement in Food Resources Study Notes

• Food is one of the basic needs of man.

• Early man lived on roots and berries of wild plants but with civilization, man learnt to cultivate plants to

satisfy his food needs.

• With continuous increase in population and rapid urbanization, our natural resources have been over

exploited.

• As a result of this, our natural resources are getting depleted at a very fast rate.

• Our major concern today is how to increase production to feed the increasing population without

damaging natural resources.

• To meet the ever-increasing demand of food to feed the increasing population, we need to take steps to

not only increase crop production, but also improve the production of animal food.

• Dairy farming, poultry farming, fish farming and piggery have increased appreciably due to the combined

efforts of the farmer‟s co-operative organizations, government agencies and co-operative banks.

• Proper management of livestock and their breeding have also played an important role in increasing the

production of animal food.

• To achieve this we also need sustainable agriculture.

Animal Husbandry

• Husbandry means farming or management of livestock, which includes various aspects like shelter, food,

breeding, health and disease control. Animals included under this are called Livestock.

• Livestock refers to all domestic animals that are used to produce food and other valuable products for

man It includes cattle, buffaloes, sheep, goats and pigs.

Types of Livestock

1) Milk producing livestock – this includes cattle farming

2) Meat producing livestock – this includes poultry farming, fish farming etc

3) Others – this includes bee farming

Cattle Farming

• Cattle farming is done mainly for two purposes.

a) Dairy – for obtaining milk

b) Drought – for transport and field work

Milk Producing Livestock

• These are milch ( milk producing) animals.

• The milk-producing animals reared in our country are cows, buffaloes, goats and camels.

• Goat's milk is very nutritious.

• Buffalo's milk has higher fat content than cow's milk.

• Buffaloes are the major source of milk in our country.

• Dr V Kurien is called the “Father of White Revolution”


There are three categories or breeds of milk producing livestock There are 26 breeds of cows in India.

1. Draught Breeds –

• Draught breeds are basically beasts of burden.

• They are used for drawing bullock carts, ploughing land and transporting material from one place to

another.

• They are strong and sturdy but give less milk.

• Example – Malvi (Rajasthan), Nageri( Haryana , UP)

2. Dairy Breeds –

• These cows are reared for yielding milk.

• The bullocks are not suitable for draught purposes.

• Examples – Gir ( Gujrat, Rajasthan), Sahiwal ( Punjab, Haryana, UP), Red Sindhi ( AP)

3. Dual-purpose Breeds –

• These cows are good milk yielders and the bullocks are good draught workers.

• Farmers in villages domesticate draught and dual-purpose breeds because these fulfill their needs.

• They provide enough milk to support a family and help in ploughing the fields or drawing water from the

wells.

• Examples – Haryana ( Haryana, Bihar, Punjab, Gujrat), Kankrej ( Gujrat)

Cow Indian Breeds (Indigenous )

• Red Sindhi - This cow is medium in size and red in colour with dark and light shades of red. It is found in

Andhra Pradesh

• Sahiwal - This is a large, heavily built cow and is of a superior breed. It is found in Panjab, Haryana and

UP

• Gir - This breed is found in Gujarat in the Gir forest and Rajasthan. This cow is medium in size and is a

good milk yielder.

• Other well known breeds are Dangi, Deoni, Tharparker and Haryana.

• They are dual purpose breeds and fairly good milk yielders.

Foreign Breeds (Exotic)

• Jersey hails from Island of Jersey, USA

• Holstein Friesian hails from Holland

• Brown Swiss hails from Switzerland

Cross Breeds

• Cross breeds are obtained by Hybridization ie by crossing animals of different breeds or species.

• The offsprings produced are called “Hybrids”.

• Hybrids show good characters of both the parents.


• They are HYV (High Yielding Varieties)

• The following are some improved breeds of dairy cows that have been developed in our country at the

National Dairy Research Institute (NDRI), Karnal, Haryana.

• These breeds were obtained by crossing an indigenous breed with an exotic breed.

• Karan Swiss : This is a crossbreed between Brown Swiss and Sahiwal

• Karan Fries: This is a cross breed between Holstein-Friesian and Tharparkar

• Frieswal: This is a cross breed between Holstein-Friesian and Sahiwal

• With cross breeding the yield of milk has increased by two or three times more than the yield from Indian

cows.

Buffaloes (Bubalus bubalis)

• Buffaloes are reared in large numbers in India. There are more than ten different breeds of buffaloes in

India. Of them, the high milk yielding breeds are:

• Murrah -This originally belongs to Punjab, UP and Haryana. The average yield of milk is 1800 to 2500

litres with 7% fat.

• Mehsana - This breed hails from Vadodara and Mehsana districts of Gujarat. The average yield is 1200 to

2500 litres. They start yielding milk at a young age and have regular breeding intervals.

• Surti - This breed is a native of Kaira and Vadodara districts of Gujarat and Rajasthan. The average yield

is 1600 to 1800 litres. The fat content is about 8-12%. This breed is highly adaptable.

• Other breeds include Nili ( Punjab and Haryana), Nagpuri ( Central and south India) . Jaffarabadi ( Gujrat)

• Buffalo milk is rich in fat , proteins, vitamin A and minerals.

Milch Animal Management

For effective livestock management and improvement in yield the following steps should be taken care of.

Shelter or housing

• Shelters should be constructed in such a way that it provides a comfortable resting place for the animals.

• It must protect the animals from rain, wind, Sun, cold and dampness.

• Floor of the shelter must have proper drainage system

Nutrition

• The total amount of feed given to an animal in 24 hours is called “Ration”

• Animal feeds have two main contents:

a) Roughage - This includes fibres like green fodder, hay and leguminous plants like berseem and

cowpea.

b) Concentrates - This contains high content of proteins and other nutrients but is low in fibres. These

include grains of maize, oats, barley, jowar, gram and byproducts of agriculture like wheat bran, rice bran,

gram husk, oil seedcakes and molasses.

• A balanced feed, which contains all the nutrients in the right proportion, is supplied to the cattle.


• On an average the daily ration for a cow is 15-20 kg of green fodder and 4-5 kg of grain mixture

Diseases of Cattle and Their Control

• The common diseases of cattle are

a) Bacterial diseases, example - tuberculosis

b) Viral diseases , example – foot and mouth disease, reinderpest disease

c) Fungal diseases, example – ring worm

Control measures

• Periodical screening of animals for the diseases

• Compulsory and timely vaccination

• Proper disposal of dead animals

• Proper Hygiene of animals and their shelter

• Hygienic handling of animal products

Diseases of Animals Transmitted to Human Beings

Meat Producing Livestock

• Besides cows, the goat, sheep and pig also provide meat.

• Goat meat is more popular in India than meat of sheep and pig.

Goat

• There are twenty different breeds of goat in India.

• Some of the well known breeds are Jamunapari, Himalayan, Bengal, Assam, Decanny, and Kathiyabari.

• Some of the exotic breeds are Alpine, Toggenberg and Sannen.

• Shelter - Goats require a place for shelter which is dry, safe and secure from predators and protected

from sun and rain

• Nutrition - Goats are fed with fresh fodder, hay of leguminous plants such as barseems and tender

leaves of trees

Sheep

• Sheep are reared for wool, skin and meat.

• They are domesticated in Rajasthan, Kutch, Saurashtra, North Gujarat, Deccan Plateau, Kashmir,

Himachal Pradesh, hilly districts of Uttar Pradesh, Sikkim and Arunachal Pradesh.

• The important breeds in our country are Nellore and Mandya.


• Crossbreeding of Indian sheep with exotic mutton breeds such as Dorset and Suffolk have been very

successful and resulted in 30-50% increase in body weight.

• Shelter - Sheep do not require well-structured shelters.

• Nutrition - Sheep feed on green tender grass, weeds and other herbage.

• A balanced ration of roughage and concentrates will ensure healthy growth.

Diseases of Goats and Sheep and Their Control

• Some of the bacterial diseases are Black-quarter, Brucellosis and Vibriosis.

• Viral infections include sore mouth, goat pox and Rinderpest

• Regular vaccinations and periodic consultations with veterinarians will prevent many bacterial and viral

diseases.

Pigs

• Pigs provide high quality meat called pork.

• Pork is used to prepare ham, bacon, sausages and chops.

• The management of pigs is known as piggery.

• Shelter - Pigs that are domesticated for the purpose of providing meat must be kept in clean shelters

called sty.

• Nutrition - Pigs normally feed on garbage, kitchen wastes, vegetables, grass, straw and grains.

• Breeding - Pigs are very economical in the sense that they give birth to nearly a dozen piglets at a time.

• So their number multiplies quickly and therefore, their produce too.

Disease - Prevention and Control

• Pig is the intermediate host for the intestinal parasite called Tape Worm.

• The cyst of the worm enter the pork.

• When man consumes pork that is infested, it can cause Tape Worm infection in man.

• Hygienic conditions while domesticating pigs and also regular vaccinations will keep the animal healthy

and will ensure healthy meat for our consumption.

Poultry Farming

• Poultry includes all domestic birds - chicken, ducks, geese and turkey.

• They are reared for their meat and eggs.

• Poultry farming in India has made rapid strides as poultry management is being done on scientific lines.

• Poultry birds reared for meat are called Broilers.

• Poultry birds reared for eggs are called Layers

• The indigenous breeds of fowls are

- Aseel or Indian Game (provides good meat but is a poor egg layer). The most popular varieties of this

breed are Peela (golden yellow), Yakub (black and red), Nurie (white) and Kajal (black).

- Karaknath and Busra.

• The exotic breeds are:


- White Leghorn - This is a highly reputed breed, which produces long white eggs. The body size is small

and consumes less feed.

- Rhode Island Red - This breed has high yield of meat and is a good egg layer.

• Some cross breeds are – HH 260, IBL 80

Advantages of cross breeds

• They are good layers

• They require less food.

Shelter and Nutrition

• Maximum yield of eggs is obtained by keeping the poultry in comfortable, well ventilated, dry, clean and

properly lighted houses.

• Birds of different ages should be kept separately.

• The first phase in the life of poultry is called the growing period and the chickens are called growers.

• During this stage the chickens require enough space.

• Overcrowding suppresses their growth.

• The second phase in the life of the poultry is called the laying period.

• This period is from the time of sexual maturity till the end of egg laying period.

• The chickens are now called layers.

• The layers require enough space and proper exposure to light (about 12- 14 hrs).

• The feed given to the poultry consists of cereals and cereal by-products of corn, wheat, rice and millets

like jowar, ragi and bajra. Oil cake or meal, protein concentrates, fishmeal or meat meal, minerals and

greens are included in the feed.

Disease and Control

• Poultry fowls suffer from a number of diseases caused by virus, bacteria, fungi, parasites and nutritional

deficiencies. Some of the diseases are fowl cholera, salmonellosis, fowl fox and parasitic infestations like

roundworm, tapeworm and threadworm.

• Bird flu (A viral infection) spread in poultry birds of many Asian countries in 2007

• Appropriate vaccinations and other preventive measures can prevent loss of poultry during an outbreak of

disease.

Breeding

• White Leghorn, Rhode Island Red, Plymouth rock, Barred Plymouth, Sussex and Minorcha are some of

the exotic breeds utilized for the improvement of egg production and yield of meat in our country.

Fish Farming

• This includes inland and marine fisheries, aquaculture and pisiculture.

• Fish is a source of high quality animal protein and a rich source of minerals like calcium, phosphorus and

iron.

• To improve the fish production techniques like Induced Breeding are used.

Freshwater Fisheries


• There are fish that are cultured in water bodies like ponds, tanks, lakes, rivers, back waters and marshy

swamps.

• Some fresh water edible fishes are –Catla (Catla catla) , Rohu ( Labio rohita)

Marine Fisheries

• These are fish that are cultured in salt-water bodies like seas and oceans.

• Some marine fish are Bombay duck, Catfish, Mackerels, Red mullet, Sardine, Salmon,, Hilsa etc.

Aquaculture

• This involves production of fishes, prawns, shrimps, lobsters, crabs and Molluscs.

Pisiculture

• This is production of some food fishes like carps. The fish are cultured in ponds and tanks.

Disease and Control

• The main causes for disease in fishes are viruses and bacteria

• Pollution of water causes great harm to the fish population.

• Fertilizers, pesticides, effluents and chemical wastes from factories contribute largely to pollution of water

bodies.

Crop Production

Plant Nutrients

• The nutrients required by plants for their healthy growth are 16 in number.

• They are carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron,

manganese, copper, zinc, boron, molybdenum and chlorine.

• Plants consume carbon element from carbon dioxide in the air, hydrogen from water, and oxygen from

both air and water

• On the basis of the quantities required, the various nutrients needed for plant growth can be classified into

two groups macro and micronutrients

• The macro-nutrients required for the growth of the plant are: Carbon, hydrogen, Oxygen, Phosphorus ,

Potassium, Sulphur Etc.

• The micro-nutrients required for the growth of the plant are: Fe, Mn, Cu, Zn B, Mo , Cl

Crop Seasons

• Kharif – Rainy season ( June - Oct)

• Kharif crops are – Paddy, Soyabean, Maize, Cotton, Urad

• Rabi - Winter season Nov – April).

• Rabi crops are – Wheat, Gram, Mustard, Sugarcane.

• Zaid – Summer season ( March – June).

• Zaid crops are – Cucumber, Melon


Fertilizers

• Constant use of the soil leads to the loss of its important nutrients particularly nitrogen, phosphorus and

potassium and thus the soil loses its fertility.

• For the healthy growth of the plant these deficiencies in the soil have to be replenished with the use of

certain materials called fertilizers.

• These can be classified under two groups.

Manures - Manures are organic materials added to the soil to increase crop production. They are biological

in origin.

• Farmyard Manure (FYM) - This is the decomposed mixture of excreta (dung) and urine of farm animals

like cow, horse, goat and sheep along with leftover hay and fodder

• Compost - This consists of a variety of farm wastes such as farm weeds, straw, sugarcane refuse, rotting

vegetables, kitchen wastes, crop stubble, ground nut and rice husk.

• Composting is a biological process in which aerobic and anaerobic microorganisms decompose organic

matter. .

• Green Manure - Green manuring is the practice of growing and ploughing in, the green crops, into the

soil. Eg .Cowpea, Lentil(Masur)

• It is a cheap and effective method that increases soil fertility as it can supplement farmyard and other

organic manures and is more cost effective.

• Green manures add nitrogen and organic matter to the soil for improving crop productivity.

• They also improve soil aeration and drainage conditions.

• Both leguminous and non-leguminous plants are grown for making green manure.

• Vermicompost -Vermicompost is a type of compost made by earthworms The soil thus produced is

mainly worm excreta and finely ground soil.


Chemical Fertilizers

• These are nutrient supplements for plants manufactured in fertilizer factories from chemicals.

• They are nutrient specific i.e., they may provide only nitrogen, only phosphorus or only potassium to the

soil

• Chemical fertilizers contain a higher amount of nutrients as against manures and so are used in very

small quantities.

• Based on the availability of nutrients in them chemical fertilizers are divided into four groups

1. Nitrogenous Fertilisers -Fertilisers that contain the macronutrient nitrogen Example: Ammonium

sulphate, ammonium nitrate, sodium nitrate, urea.

2. Phosphatic Fertilisers -Fertilisers that contain phosphorus Example: Superphosphate, ammonium

phosphate, calcium phosphate (bone meal)

3. Potassic Fertilisers -Fertilisers that contain potassium Example: Potassium chloride, potassium

sulphate, potassium nitrate

4. Complex Fertilisers - When a fertilizer contains two or more nutrients Example: NPK ( Nitrogen,

Phosphouous and Potassium) Nitrophosphate, Ammonium phosphate, and urea ammonium phosphate

• Although chemical fertilizers do increase crop yield, their chemicals get washed away through irrigation,

rainfall and drainage and reach rivers, lakes and streams.

• They pollute water bodies and disturb the ecosystem.

• Therefore chemical fertilizers should not be used indiscriminately.

Water

• In India Agriculture mainly depends on Monsoons

• The monsoons bring in lot of rainfall. More than 55% of our cultivated land does not have irrigation

facilities and depends on rainfall.

• To increase food production the water resources of the country should be managed.

• India has 12 major river basins and 8 composite river basins that form the surface water resource.

• Besides, the ground water also adds to the total water resource.

The following steps could be adopted to use water resource effectively :

• Selecting appropriate crop and cropping system

• Application of optimum quantity of water at the right time

• Controlling weeds ( weeds will also absorb water)

• Controlling pests

• Avoiding wastage of water

Different types of irrigation systems are essential for better water management.

Irrigation System


- The process of supplying water to crops in the fields by means of canals, reservoirs, wells, river valley

systems and river lift systems is known as irrigation.

Canal System

- This system receives water from one or more reservoirs or from rivers.

- It consists of a main canal which distributes water into branch canals and branch canals have further

distributaries or channels which serve water to individual fields.

Reservoirs (Tanks)

- There are small storage tanks which intercept and store the overflow of smaller catchment areas.

Wells

- Wells are dug wherever underground water is present.

- Wells are of two types open wells and tube wells.

Protection of Crops

• Certain preventive measures can be adopted to protect crops from weeds, insects, mites, rodents and

fungi.

• They are:

- Use of resistant varieties

- Optimum time of sowing the crops

- Crop rotation and cropping system

- Clean cultivation

- Summer ploughing

Pest Control

• Plants often get infected with disease causing pathogens. The entire crop can be destroyed if they are not

controlled in time.

• Pathogens are transmitted by: seed , soil , water and air

• Pesticides like malathion, aldrin, phosphate granules are used

Weed Control

• Weeds are unwanted plants that grow in the fields where crops grow.

• The growth of weeds in fields has an adverse affect on crops because they compete with the crops for

space, light, nutrients and water.

• The yield becomes poor and so also the quality of the crop.

Methods For Controlling Weeds

1. Mechanical Methods

- pulling them out (uprooting) with hand

- removal by using a hoe or trowel

- ploughing

- burning

- flooding


2. Cultural Methods

- proper seed bed preparation

- timely sowing of seeds

- intercropping and

- crop rotation

3. Chemical Methods

- Spraying of special chemicals called weedicides or herbicides Example: atrazine; 2, 4-D, fluchloralin;

isoproturon

4. Biological Method

- The biological method involves the use of some appropriate insects or some other organisms on the crop

field having weeds.

- They selectively destroy the weed plants but do not harm the crop plants. Example: Cochneal insects are

used to eradicate opuntia (a weed, commonly called prickly pear).

- Aquatic weeds are controlled by grass carp (a kind of fish).

Scientific Storage of Grains

• Besides crop production, good crop management involves storage of grains

• During storage, grains and seeds are subjected to spoilage by various agencies. These agencies are

either biotic or abiotic.

- Biotic(living) - insects, rodents, birds, fungi, mites, bacteria - Abiotic (non living) - moisture and

temperature

Measures to Prevent Loss during Storage

• Drying

- At the time of harvesting the moisture content in grains and seeds varies from 15-35%.

- Grains have a tendency to absorb moisture from the atmosphere.

- If the moisture content is high, seeds are prone to be infested with pests and this in turn will decrease

their quality.

- Hence moisture content in grains and seeds must be reduced to below 9% for their safe storage.

- To maintain the desired moisture content in the seeds they are dried in sun

• Hygiene - Granaries, godowns and stores should be well cleaned before stacking fresh grains.

• Prophylactic (preventive)Treatment -As a preventive measure godowns should be treated with

insecticides and pesticides.


• Gunny bags should also be sprayed with pesticides. Grains that have to be used for seed purpose must

be mixed with fungicide and insecticide.

Modern Storage Structures

• Research organizations have developed improved storage structures which have proved comparatively

safe for the storage of grains.

• In these structures, temperature, moisture, oxygen and carbon dioxide can be adjusted to protect the

grains.

• The structures are airtight, moisture proof, thermally insulated and rodent proof.

Changes in outside temperature do not affect the grains stored in these structures.

• Some of these storage structures are Pusa Bin, Pusa Cubicle, Pusa Kothar and Pant Kuthla.

Pest Control

• It is not safe to mix insecticides and pesticides with grains meant for human or animal consumption. If any

of these are used they should be within safety norms.

• Chemical Control - Spraying of BHC , pyrethrum and malathion

• Many of these chemicals are contact poisons and care should be taken while

using them. Gloves and masks should be used by the person spraying the

chemical.

• Fumigation - Fumigants are chemicals that can exist in sufficient concentration

to be lethal to pests Eg - Aluminum phosphide tablets (black poison)

• Plant Products -Often a small quantity of vegetable oil or mineral oil is added to grains of legumes to

protect them from insects. Some of the plant products used for this purpose are clove oil, neem oil or

leaves, kernel powder, crushed pepper etc.

Sustainable Agriculture

• Sustainability means keeping an effort going continuously, or the ability to last out and keep from falling.

• So sustainable agriculture means successful management of resources for agriculture to satisfy the

changing human needs, while maintaining or enhancing the quality of environment and conserving natural

resources.

Importance of Sustainable Agriculture

Sustainable agriculture is an agricultural production and distribution system that

- Achieves the integration of natural biological cycles and controls

- Protects and renews soil fertility and the natural resource base

- Optimizes the management and use of on-farm resources

- Reduces the use of non-renewable resources

- Provides an adequate and dependable source of income


- Promotes opportunity in farming

Sustainable agriculture can be achieved by adapting:

- Mixed farming

- Mixed cropping

- Crop rotation

- Crop selection

- Variety improvement

Mixed Farming

• Mixed farming includes crop production, raising of livestock, poultry, fish and bee keeping and piggery

together .

• Modern day farmers specialize in one agricultural sector, either dairy or growing potatoes

• But their ancestors used to keep a variety of farm animals and planted many different kinds of field crops.

• Their farms were remarkably self sufficient, producing eggs, meat, milk, vegetables and grains for the

family and all the fodder and hay for the farm animals.

• They could get sufficient for their fields.

• The oxen were used to draw water from the well and help plough the fields.

• In this system of farming products and even waste from one place are put to good use at another place.

• Food-fodder Farming System -Growing food grains like rice, maize, wheat and fodder crops like

sorghum, oat and berseem

• Agro-forestry System -Raising crops along with trees like silver oak with pepper, silver oak with coffee

etc.

• Horti-pastoral System -Growing fodder grasses with fruit trees

Mixed Cropping

• Mixed cropping is growing of two or more crops simultaneously on the same piece of land.

• It is also known as multiple cropping.

• This type of cropping leads to an improvement in the fertility of the soil and hence, increase in crop yield

because

• Mixed cropping is an insurance against crop failure due to abnormal weather conditions.

• Some successful mixed crops are:

Soyabean + Pigeon pea . Maize + udad dal (Black gram)

Pigeon pea + Mung dal (Green gram) Groundnut + Sunflower

Sorghum + Pigeon pea Wheat + Chickpea

Barley + Chickpea Wheat + Mustard

Cotton + Groundnut

• Mixed cropping has proved successful because of the right selection of crops.


Advantages of Mixed Cropping

• No Risk of Crop Failure -The risk of total crop failure due to uncertain monsoon is reduced if two crops

of different nature are grown simultaneously as a mixed crop.

• Variety of Produce - A variety of produce could be obtained from a single crop to meet the requirements

of the family like cereals, pulses, vegetables etc.

• Increase in Yield – One crop may help in increasing the production of the other crop. For example,

legume crops have a beneficial effect on cereal or non-legume crops as they help in fixing nitrogen in the

soil.

• Improvement in Soil Fertility -The growth of cereal crops depletes the soil of nutrients. Growing

legumes will help increase the nitrogen content in the soil.

• Minimizing Pest Damage – a particular type of crop is more prone to a particular type of pest infection.

When different types of crops are grown together chances of pest infections are minimized

Crop Rotation

• The growing of different kinds of crops on a piece of land in a preplanned succession (interval) is known

as crop rotation.

• In the rotation of crops, leguminous crops like pulses, beans, peas, groundnut and Bengal gram are sown

in-between the seasons of cereal crops like wheat, maize etc.

• The leguminous plants are grown alternately with non-leguminous plants to restore the fertility of the soil.

• When the cereal crops like rice, wheat, maize are grown in the soil, it uses up a lot of nitrogenous salts

from the soil. If another crop of cereal is grown in the same soil, the soil becomes nitrogen deficient.

• So by rotation, a leguminous crop is grown.

• Leguminous plants have symbiotic bacteria (Rhizobium) in their roots which convert nitrogen compounds

in to usable form for the plants.

Advantages of Crop Rotation

• Rotation of crops improves the fertility of the soil and hence, brings about an increase in the production.

• Rotation of crops helps in saving on nitrogenous fertilizers

• Rotation of crops help in weed control and pest control.

Variety Improvement

• The yield of wheat and rice which stood at 668 kg and 663 kg per hectare respectively in 1952 increased

to 1851 and 1468 kg per hectare in eighties.

• The production has tripled in thirty years.

• This increase in food production has marked a turning point in Indian agriculture, which has led to

Green Revolution in our country.

• The revolution is called green because it led to unprecedented greenery of crops everywhere.

• It is because of the green revolution that our country has become self sufficient in food production and has

a large stock of food grains for use in the times of natural calamities like drought, floods and famine.

• The various factors, which collectively led to the green revolution in our country, are:


- Introduction of HYV (high yielding varieties) of Mexican wheat

- Proper irrigation

- Increased use of fertilizers, weedicides and pesticides

- More land under cultivation

- Improved soil practices and agricultural techniques

Need For Variety Improvement

• Population grows in geometrical proportions but food production grows in only arithmetical proportion.

• With the ever increasing demand for food grains, fodder, fibre, vegetables, fruit, sugar and oil, there is an

urgent need to increase crop production, as our land resources are limited.

• So there is an urgent need for improvement in variety of crop plants.

• The variety developed should be superior in quantity as well as quality.

Plant variety can be improved by any of the following method

Plant Breeding

• The main aim of plant breeding is to produce new crops superior to the existing ones.

• To improve the breed, plants are crossed ( reproduced) with their wild relatives

• By this method new varieties of crops, having higher yield, resistant to pests and disease can be grown.

• Hence, plant breeding can be defined as a science as well as art of improving genetic make-up of plants

in relation to their economic use

Selection

• It involves picking the healthiest and the best ones out of the entire crop and reproducing them under

controlled conditions.

Hybridisation

• It is the technique of introducing characters of two desirable plants into a single offspring (hybrid) by

means of artificial pollination.

• This involves crossing of genetically dissimilar plants.

• Raphonobrassica (Rabbage) is a cross between cabbage and radish,

• Triticale is a cross between wheat and rye,

• Pomato is a cross between potato and Tomato

Apiculture or Bee keeping

• It is an age old industry

• Bees are cultured for Honey and wax

• Bees live in a colony known as „Hive‟

• Colony of Bees is well organized and shows „Division of labour‟

• A colony of bees comprise of 3 casts

- one Queen bee ( fertile, diploid female)

- many workers ( sterile , diploid females)

- many drones ( haploid males)


• Queen bee is largest of all and her job is to lay eggs.

• Eggs are of two types, fertilized and unfertilized

• Unfertilized eggs develop in to Drones, which are males.

• The process of development of Unfertilized eggs in to drones is called „Parthenogenesis‟.

• Fertilized eggs which are fed with „Royal Jelley‟ develop in to Queen and the ones fed with „bee bread‟

develop in to workers.

• Workers are smaller sterile females.

• Worker bees perform various functions like building and cleaning of hive, taking care of young ones,

collection of pollen etc.

• Drones are small and fertilize the eggs.

• Bees show metamorphosis ( various stages of development) .

• Indigenous breeds are –Apis indica, Apis dorsata (Rock bee), Apis florae (little bee)

• Exotic breed is Apis mellifera .(Italian bee)

• We obtain honey and wax from bees.

• Honey has medicinal value and is a good substitute of sugar.

• Bee wax is used in batique printing..

• Pasturage – the plants from which the bees collect pollen and nectar.

Class IX Science (Biology) Improvement in Food...

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