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close this bookBiodiversity in the Western Ghats: An Information Kit (IIRR, 1994, 224 p.)
close this folder5. Agriculture
View the document5.1 Rice diversity and conservation in the Konkan
View the document5.2 Conservation of traditional vegetables in the backyard
View the document5.3 Genetic diversity in mango and cashew
View the document5.4 Floriculture and arboriculture
View the document5.5 Enriched biodiversity by plant introductions
View the document5.6 Impact of introduced plants
View the document5.7 Effects of pesticides on biodiversity
View the document5.8 Khazan (saline) lands

5.1 Rice diversity and conservation in the Konkan

The spread of high-yielding varieties means that in 15 years just 10 varieties may cover as much as 75% of the total rice area. The country's rich genetic diversity in rice is being destroyed.

Some 50,000 rice varieties are grown in India. This is a very rich source of genetic variety, of great value for plant breeding.

But government officials and industry have promoted only a very few "modern" rice varieties. The spread of high-yielding varieties means that in 15 years just 10 varieties may cover as much as 75% of the total rice area. The country's rich genetic diversity in rice is being destroyed.

This diversity is a result of centuries of selection by farmers, adaptation to various environments, breeding with wild relatives and local varieties, and the evolutionary process over centuries.

In the Konkan region of Maharashtra, hundreds of indigenous cultivars were cultivated. The sophistication and stability of rice farming can be judged from the fact that even the smallest tribal farmer, with a land holding of less than a hectare, had six to eight varieties of traditional seeds suited to local microclimates and soils.

But farmers are replacing these hundreds of cultivars with just six or seven high-yielding varieties. This is reducing the genetic background of rice varieties over wide areas in the Konkan. This genetic erosion poses a danger to the long term food security of the region.

Conservation

Now efforts are on to conserve these valuable rice varieties. ADS, the Academy of Development Sciences in Karjat is painstakingly collecting samples of rice varieties which have been grown in this country over generations.

While many of the old varieties have disappeared, many still survive. Some "orthodox" and "stubborn" farmers still stick to planting traditional varieties of paddy, Around 300-400 traditional varieties of rice are currently grown in the Konkan, according to an ADS study.

ADS has a three-acre field gene bank and seeks to encourage the use of traditional seeds by farmers. ADS workers meet farmers and seek their help to identify farmers who still have traditional rice-varieties in their fields. They ask for a few panicles of the rice, which are then taken back and replicated at ADS. They can then be once again promoted among farmers for cultivation.


A rice field

Amazing diversity

Rice has amazing diversity. In colour alone, the grain varies from white to red, brown and black. This diversity is a result of selection by farmers. adaptation to various environments, breeding with wild relatives and local varieties, and the evolutionary process over centuries. Rice of different types can be differentiated one from another on the basis of various characters.

For instance, there is the yield and duration of the crop. Rice varieties also vary in terms of their ability to withstand excess or shortage of water, their ability to grow in acid, alkaline or saline conditions, and their resistance to pests and diseases.

Rice varieties also differ from one another in terms of habitat; plant height; leaf shape, size and colour; ligule and auricle; grain shape, size and colour; features of the panicle; sterile/fertile lemma; and the awn.

Dangers of uniformity

Going in for genetic uniformity is fraught with dangers, warns ADS.

Industrial monocultural agriculture and its high-yielding varieties favour genetic uniformity. Vast areas are planted to a single variety, requiring expensive inputs such as irrigation, chemical fertilizers and pesticides to maximize production. In the process, not only traditional crop varieties, but long-established farming ecosystems are obliterated.

Genetic uniformity invites disaster because it makes a crop vulnerable to attack. A pest or disease that strikes one plant can spread quickly throughout the crop. In some regions, the risk is considerable: Some 62% of the rice varieties in Bangladesh, 74% in Indonesia and 75% in Sri Lanka are derived from one maternal plant.

Farming the Konkan

Agriculture in the Konkan-the narrow strip of land along the Bombay-Goa belt-is mainly rainfed. Lands in the Maharashtra part of this region are divided into Garva lands (with good water), Neem-Garva lands (with medium water holdings), and Halva lands (with poor soil).

Indigenous vs modern rices

Modern rice varieties have high yields, but they lose to indigenous varieties when it comes to other characteristics.


Indigenous varieties

Modern varieties

Ability to withstand water stress

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Ability to withstand adverse soil conditions

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Resistance to pests and disease

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+/-

Conservation of gene banks

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-

Cost of inputs

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Genetic uniformity invites disaster because it makes a crop vulnerable to attack.