In a popular TV show in India, advice was given not to use pesticides and go for organic farming. Most of the villagers in earlier times were engaged in organic farming alone as they had no access to pesticides or fertilizers due to remoteness, lack of knowledge or paucity of funds. No doubt the government of India has spread the knowledge about agriculture to villages and now its quite common that villagers use both. However, more so in the case of cash crops like cotton, sugarcane or vegetables.
GM food could be one answer to the problem of pests and productivity, and several countries use GM crops in millions of hectares but in Europe, Japan and the Indian subcontinent they face stiff opposition. The introduction of genetically modified cotton - Bt Cotton - has been a boon to cotton growers of Gujrat and elsewhere. The use of GM plants for non-food items would not attract much criticism as one is not eating the plants or plant products.
However, not going into this controversy I wish to say that if the farmers follow advice of Mr. Amir Khan in his TV show, not to use pesticides and fertilizers, we are turning the wheel in the other direction. It is a retrogressive step. The correct approach would be use of bio-pesticides like Neem cake, Neem leaves, Calotropis latex, and other bio pesticides studied in our lab. My colleague Professor P.C. Trivedi currently VC of Gorakhpur University or Professor Manoharchari of Usmania University Hyderabad have extensively worked and advocated the use of biopesticides. Early sowing , early maturing crops, use of sanitation, improved cultural practices or use of resistant varieties could be another option.
Mustard, which used to suffer from white rusts and pests this year gave excellent yield in Rajasthan mainly due to use of improved cultivars. Wheat rust, which played havoc some decades ago, is now difficult to find in plains. However this is a highly technical matter and needs detailed analysis but just to advise farmers not to use pesticides at all is not wise.
What one should suggest is:
1. Do not use pesticides when the crop is in ripening stage and is about to come to market. The worst part of chemicals is when farmers or middle men use heavy doses of pesticides on crop plants, vegetables so that all vegetables looks so fresh and shiny. Cauliflower is marble white and free from insects. What the middleman or farmers do is to dip the cauliflower in the pesticide solution that is why it appears insect free and marble white.
2. Use biodegradable pesticides i.e. simple pesticides based on sulphur, or copper or even organo metallic substances may not do as much harm as the systemic fungicides which are taken up by plants and transported across the plants. They remain in plant body for around 15 days hence no systemic fungicide should be sprayed in this period when the vegetable is about to reach market.
3. Plants generally take minerals in ionic form. The organic fertilizers are basically used to bind the soil but the nitrogen or for that matter most of macro and micro nutrients are taken up in inorganic form and in ionic form. Plants are not animals who can take up and digest proteins, or organic compounds from nature. Plants have to synthesize their food from inorganic carbon, nitrogen and minerals, although this again varies with the plant species.
Hence, the concept of organic farming needs to be understood in the right perspective. A suitable combination of organic farming and cultural practices could help prevent disease in the field but once it appears the use of pesticides is a must, choice is very limited - unless we use genetically modified plants.