The control of the diamond black moth in cabbage crops has long been a challenge for scientists and farmers. Over the last three-four decades, many chemical pesticides have made spectacular promises to take on the bug, only to be defeated by the amazing ability of the insect to adapt to new chemical molecules for its survival.Now, it seems, a solution may be finally at hand. Botanicals, or Integrated Pest Management — essentially, the use of natural products to control pests — may be the answer that has long eluded scientists.The guinea pig in this case are the cabbage fields of farmers in the Bangalore rural district. Normally, they sprayed each cycle of their crops 10-15 times with chemical pesticides and fungicides at a cost of Rs 16,000-Rs 18,000 Then, scientists of the Indian Institute of Horticulture Research (IIHR) introduced the integrated pest management technique — a spray of home-made 4 per cent neem seed kernel — at intervals of 20, 30, 40 and 50 days after the transplantation of the cabbage.Though farmers found the spray effective, they thumbed it down because of the tedious preparations involved. The IIHR scientists then refined the process by powdering the whole neem seed and then spraying it on the crop. Further, to cope with the non-availability of the neem seeds in summer, the scientists thought up a semi-solid soap comprising neem and pongamia oil. Both methods have found popularity with farmers in the entire rural Bangalore district, more so because it slashes their pesticide costs to Rs 4,000Apart from its pesticide value, the soap — a salt of potassium — has been found to add to the potassium status of the cabbage, increase crop resistance and thereby increase yield. Farmers are now able to control pests in an effective and sustainable way. Even if the market price of cabbage falls, farmers are still able to rake in profits because of Rs 12,000/hectare savings in the cost of pesticide.
