Silent Spring was published in 1962. In it Rachel Carson raised an accusing finger at the indiscriminate use (often as an aerial spray) of the insecticide DDT, (dichloro diphenyl trichloroethane). She shook the collective conscious of the society to take note of the environmental deterioration happening around; what the pesticide was doing to the bees and birds. The use of DDT as a pesticide was finally banned in the US in 1972. Half a century later we are still struggling with pesticides; should we or shouldn't we? In 2012 alone over 3500 research papers have been published on the lingering effects of pesticides in the environment. Even so in 2012 the pesticides' sale stood at several billion dollars ( the break up goes like this . Herbicides: 40% , Insecticides: 33%, Fungicides: 10%, Others: 10%)
This is the current state with ~6 billion population. Another three and a half decades and human population will touch the 9 billion mark. Farm lands will shrink to yield space for housing colonies and offices. With limited agricultural land, how to feed the 9 billion? Quite a challenge and many living today will get a chance to witness it, because 2050 is near future. The question is can we repose faith in fertilizers and pesticides alone to double, triple or quadruple the farm output? As facts stand today this will be suicidal. Because fertilizers don't distinguish between crop and weeds and pests have developed resistance to several pesticides. Besides in many places environmental accumulation of pesticides have begun to spell disaster for human beings as well.
This is the current state with ~6 billion population. Another three and a half decades and human population will touch the 9 billion mark. Farm lands will shrink to yield space for housing colonies and offices. With limited agricultural land, how to feed the 9 billion? Quite a challenge and many living today will get a chance to witness it, because 2050 is near future. The question is can we repose faith in fertilizers and pesticides alone to double, triple or quadruple the farm output? As facts stand today this will be suicidal. Because fertilizers don't distinguish between crop and weeds and pests have developed resistance to several pesticides. Besides in many places environmental accumulation of pesticides have begun to spell disaster for human beings as well.
What alternatives do we have? Or do we have alternatives? It is indeed true that science and technology have been our constant companions helping us to improve quality of life in many different ways. However it is necessary that we exercise caution and discretion, or else we land up in greater dangers. August 16th issue of Science has reviewed the current situation with respect to pesticides. Several articles reiterate the need to adopt an Integrated Pest Management Program worldwide .Two reports one is from down under and the other from Vietnam, are eye openers.
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| Ryegrass Courtsey : Wikipedia |
Ryegrass menace has been with us from biblical times.It is a persistent weed which grows alongside wheat crop. And the weed enjoys unhindered growth in Australia. Initially Hoegrass, a herbicide could contain the weed. Then gradually the dosages had to be increased and ultimately the weed developed resistance to the herbicide. Then farmers switched to other herbicides, but to no avail, because continuous use and large doses again led to herbicide resistance. Then AHRI (Australian Herbicide Resistance Initiative), set up by Powles, himself a farmer, took up the responsibility to educate farmers. First of all, the farmers were told that they MUST read the label and follow precisely the directions on the label regarding the usage and dosage. They must not exceed the recommended doses. Second, just like crop rotation, they must keep changing the herbicide every year, so that the weed doesn't get time to develop resistance. These steps together with mechanical destruction of the weed seeds have proved immensely useful.
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| Brown Planthopper Courtsey: RRI supports Thai move to stop insecticide use in Rice |
The other story comes from the lush green rice fields of Mekong delta in Vietnam. With help from the International Rice Research Institute (IRRI, Philippines), farmers here have learned to cut down on pesticides by almost 80% through the practice of Integrated Pest Management Program. Planthoppers (Nilaparvata lugens) is the biggest enemy of rice crop and bees and wasps are its predators. Now along the field dividers, farmers grow a variety of plants including flowering plants. The flowers attract bees and wasps which feast on the planthopper larvae on the rice plants then settle on the flowers for the dessert of nectar.
We may not be able to say NO to pesticides altogether but we can definitely reduce and even eliminate their ill effects by judicious usage.
Reference
1. Silent Spring : Rachel Carson, Penguin Classics ISBN:9780141184944
2.Science 16 August 2013 special section on Pesticides
2.Science 16 August 2013 special section on Pesticides
