Why are high yielding varieties needed?

Answer 1

The core of the green revolution was the development and propagation of High

Yielding Varieties (HYV) of seeds, particularly rice and wheat, adaptable to local

ecologies. The new HYVs are designed to be high yielding in response to high levels

of inputs. These sturdy, short-stemmed plant types are capable of carrying the heavy

growth of grains.

HYV technology comes in a package of HYV seeds - water - fertilisers. All these

are needed together, in correct proportions and at various stages of growth and yields can be increased by 50 to 200 percent. You may note that HYV seeds are landsaving and labour-using innovations. They are also neutral to scale of operations and therefore usable by all farmers regardless of farm size.

Sensitivity to Water

Performance of HYV seeds would depend upon adequate control of weeds and

pests. However, water control is the most critical factor. Even in irrigated areas minor laterals are often insufficient and drainages are rarely built. Thus the exact water control required for HYVs can hardly be expected. As mentioned earlier, the HYVs were developed according to the prototypes in the temperate zone. The prototype had been developed within the favourable environmental conditions with irrigation systems that allowed precise water control. Both inadequacy and excessive water are harmful to the HYVs. Not only water should be available in desired quantity, its use has to be tailored to the needs of the plant at different stages of its growth.

Sensitivity to Fertiliser and Pesticides

The HYV seeds have the technical capacity of turning soil nutrients into larger

amounts of grains than leaf growth. Hence any increase over and above that is

possible with the existing natural nutrients of the soil can be brought about by application of chemical fertilisers. Higher the amount of such inorganic fertilisers, larger is the output of grains.

Use of fertilisers gives rise to the growth of weeds on a large scale. These seeds

being new to the soil and non-acclimatized to the region these are prone to local pests and diseases, which is not the case with indigenous traditional varieties. Hence there is a greater need for application of germicides and pesticides.

Short-duration Maturity

These seeds mature into plants in a shorter period of time and these are nonphotosensitive, i..e., their period of maturity is independent of the length of exposure to the sunlight. Moreover, these plants are dwarf in size, i.e., the plants are of much shorter stature as compared to the indigenous variety. But HYVs are laden with abundant grains. For these reasons it becomes necessary that harvesting is done over a short period.

Two consequences follow from the above.

a) Because of short-duration and photo-insensitivity there is a possibility of multiple

cropping in a year. In this respect, new technology is land-saving. Since each

crop requires lesser time to mature, land is available for more than one crop.

b) The quick maturing requires the protection of harvested crops. As a result,

drying and storage are also important.

The initial results of HYV in terms of production yields were dramatic in the ideal

conditions causing observers to call this development nothing short of revolution

though green variety. Since such prerequisites for introduction of HYVs was present

in only North West region of the country (consisting of Punjab, Haryana and Western UP) and the South Eastern regions, (consisting of coastal Andhra, Tanjore district in Tamil Nadu) these were introduced first in those regions. Since the results in terms of improved yields and profits were good, the existing regional inequalities between these regions and other regions increased further. Adoption of this technology helped in realisation of the immediate objectives such as: i) boosting production, ii) doing away with imports, and iii) feeding millions of people.

As we discussed in Unit 11 India has much variations in terms of climatic condition

across regions. These regions differ in terms of climate, soils, irrigation systems,

farming systems and historical developments. Keeping this in view the country is

divided into agro-climatic zones. Basically we have the following major types:

1) Alluvial Plains (North Western) consisting of Punjab, Haryana and Western UP.

2) South East Deltas (Krishna, Godavari and Kaveri deltas consisting of coastal

Andhra, Tanjore in Tamil Nadu).

3) Poor but potentially rich areas (Middle and lower Gangetic basin consisting of

Eastern Uttar Pradesh, Bihar, Bengal, Assam and Orissa).

4) Peninsular India / semi aid areas: consisting of Maharashtra, parts of Gujarat,

Andhra pradesh and Karnataka)

5) Arid Areas (Rajasthan and parts of Gujarat)

In terms of economic development, these agro-climatic zones can be divided into

three groups: (a) advanced area, consisting of (1) and (2); (b) potentially rich but still

very poor zones consisting of (3); and (c) Peninsular India consisting of (4) and (5)

which face severe natural constraints.

All the ingredients for introducing HYVs were present in alluvial plains and South

Eastern deltas, viz., rich irrigation sources (tube wells in North West and canal

irrigation in South East); (ii) developed infrastructure (with roads and electrified

villages); (iii) resourceful and dynamic farming communities eager to welcome new

innovations with a view to get richer; and (iv) political stability and more responsive

government machinery. Government provided inputs such as seeds, fertilisers and

pesticides. In addition, institutional credit to facilitate easier purchase of these inputs

was also emphasised. This led to immediate spurt in growth, providing cushion to the government.