Perspectives on Crop Protection in India
Introduction
India is an agrarian country with more than 60% of its population directly or indirectly dependent on agriculture which contributes nearly 18% to country’s GDP. Ensuring food security for a population of more than 1.27 billion with diminishing cultivable land resource is a herculean task. The green revolution technologies helped the country to increase food grain production from 82 million tonnes in 1960–61 to 176 million tonnes in 1991–92 and further to 264 million tonnes in 2013–14. This steady increase in production of food grains has been brought about through the introduction of high yielding varieties of wheat and rice with appropriate agronomic and plant protection technologies. According to an estimate, India would require more than 450 million tonnes of food grains to feed 1.65 billion people by 2050 which will be a very difficult task. The substantial increase in food grain production over the years has helped to meet the food security needs of the country, but, on the other hand, it has created a stress on the natural resources in some regions, particularly in te North-Western states, leading to a fall in ground water level and a deterioration in soil health. Likewise, cultivation of crop varieties with a narrow genetic base and loss of on-farm biodiversity over the years has led to the emergence of new insect pests, diseases and weeds which, if left unmanaged, can adversely affect crop productivity.
Plant protection strategies have assumed significance in the overall crop production programmes for sustainable agriculture and aim at minimizing crop losses due to ravages of insect pests, diseases, weeds, nematodes, rodents, etc. Although no exact estimates of total crop loss in India due to insects, diseases and weeds could be found, it is generally believed that on farm yield losses could range between 10–30%. In terms of monitory value, the losses due to these biotic factors account to near US$12 billion. In many regions of India, where adequate postharvest storage facilities are not available, these losses, especially in fruits and vegetables, can be much more.
Biotic stresses in Indian agriculture
wheat crop showing infection of yellow rust
Because of the diversified agro-ecosystems, a large number of crops are grown in India which often serve as the hosts to different kinds of insect pests and pathogens. Most of the Indian regions being sub-tropical to tropical, the agro-climate is more conducive for the development of insect pests than disease causing pathogens. Lepidopteran, coleopteran and dipteran insect pests cause severe yield losses in many of the commercial crops grown all across India. For instance, Helicoverpa armigera infests a variety of crops like cotton, tomato, brinjal, cabbage, cauliflower, okra, red gram, etc. Some insects, like white flies and aphids, also serve as vectors for spreading viral diseases in plants. Fungal diseases in many crops of commercial importance are a problem in India during the rainy season. The genus Phytophthora is the most severe on many crops such as potato, citrus, rubber, black pepper, cardamom, etc. Downy mildew and powdery mildew affect a wide range of crops (cucurbits, grape, wheat). Rusts, espeially stripe rust of wheat (Puccinia striiformis) have emerged as a serious problem in wheat in the North-Western plains of India. Fusarium species are responsible for causing wilt diseases in several field crops. Bacterial diseases also cause huge economical losses, particularly diseases caused by the genus Xanthomonas, which include blights in rice and cotton and canker in citrus. Another genus, Psuedomonas, is responsible for serious bacterial wilts in solanaceous and other crops.
Problems due to soil insect pests and nematodes are also on the rise because of soil climate change. This is true particularly for shallow rooted crops like cardamom and banana, and vegetables grown in poly-net houses. Likewise, certain weeds, if not managed properly, can cause considerable stress on crop plants such as Phalaris (in wheat), Echinochloa (in rice), Trianthema (in maize and cotton), etc. leading to reduction in yields.
This is an extract of the full article published in: Outlooks on Pest Management – June 2015 issue.
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Author: Tarlochan Singh Thind – summarises the state of crop protection in India
Category: Agriculture
