IK Monitor Research (8-3)

Indigenous Knowledge and Development Monitor, November 2000

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Research, projects

Indigenous technical knowledge for controlling pigeonpea pod borer
Pigeonpea is a vital source of protein for the rural and urban poor of India. It is mostly cultivated under rain-fed conditions, either on its own or in combination with other crops such as cotton, sorghum, maize, or green gram. The major constraint in pigeonpea production is the pod borer (Helicoverpa armigera), an insect that causes crop losses of up to 100 per cent in spite of several applications of insecticide. The pod borer has become increasingly difficult to control. Recent surveys of insect pests indicate that prior to 1975 fewer than 20 per cent of pigeonpea farmers used insecticide to get rid of pod borer, but by 1993 the percentage had increased to 100 per cent. This has meant higher costs of cultivation, health hazards, and environmental pollution.

The Centre for World Solidarity, an international NGO working for sustainable development in India, is conducting a programme of integrated pest management (IPM) for the cultivation of pigeonpea and chickpea crops. The programme is sponsored by IFAD (International Fund for Agriculture Development) and ICRISAT (International Crops Research Institute for the Semi-Arid Tropics). During the promotion of IPM, we and other project workers witnessed an indigenous technique that resource-poor farmers have been using for the last 60 years. It involves shaking the plants in order to dislodge and then destroy the pod-borer larvae. We systematically analyzed the results of this technique and found it to be very effective.

During the 1998-1999 growing season, ICRISAT and the Centre for World Solidarity carried out this study of an indigenous practice among pigeon pea farmers in Ranga Reddy and Mehboob Nagar districts of Andhra Pradesh, India. The practice is known as 'shaking and killing'. Two women or men walk on either side of the row of pigeonpea plants and shake each plant. At the same time two children drag a polythene sheet or cloth along the ground to collect the dislodged caterpillars, or pod borer larvae, which are then destroyed by burning or burying. Resource-poor farmers generally involve the whole family in this practice.

It was recorded that in the months October and November, when infestation is at its peak, an average of 10-12 larvae are dislodged from each pigeonpea plant. This means a success rate of 97 per cent, a score impossible to achieve with insecticidal sprays. The effects of manual shaking on pigeonpea flowers and pods were also studied. It is important to note that 70 per cent of all pigeonpea flowers naturally drop off, leaving only 30 per cent to develop into pods. Manual shaking of flowers caused 16 per cent of them to drop off, 20 per cent of which were healthy (not infected). Shaking of pods caused a negligible 3 per cent to drop off, 66 per cent of which were insect-damaged.

The traditional shaking technique has been identified as the most effective component in the integrated pest management programme for pigeonpea. It is known as 'the mechanical control option'. It is also an economical method. Resource-poor farmers usually employ their families, but even if labourers are hired, 10 labourers at a rate of IRS 35 per day cost IRS 350 per hectare, whereas any kind of insecticidal spray costs IRS 700 per hectare. The researchers who conducted this study have recommended that the traditional shaking method for controlling pod borer be promoted in the other pigeonpea-growing areas of India as well.

For more information, please contact: S.M.A. Ali, M.Sc., DCP., CPS, Centre for World Solidarity, H. No. 12-13-438, Street No. 1, Tarnaka, Secunderabad, 500 017 A.P., India.
Tel.: +91-40-701 7735.
Fax: +91-40-701 8257.
E-mail: smaali786@joymail.com

Photos.