Boston — Researchers are increasingly convinced they've come up with a way to wean US farmers away from pesticides and still win the battle of the bugs.
Purdue University entomologist Tom Turpin, along with an increasing number of experts in the field, advocates a system he says offers a broad array of both chemical and natural means of pest control--integrated pest management (IPM).
A report by a task force on IPM commissioned by the Council for Agricultural Science and Technology (CAST) defines IPM as a ''strategic mix of methods to control pests which will maintain an economic food and grain production while keeping the bad effects to a minimum.''
The report notes that ''although IPM is a new term to many people, combinations of methods for controlling pests have been used for a long time.'' Farmers, for instance, have long used crop rotation along with other methods, including chemicals.
What is new is the commitment of government and scientists to bring all the technology together into workable systems through the help of computers.
Several IPM experiments are under way across the United States:
* University of Florida scientists are using a computer to handle the integration of pest management systems in their state. They have started with the north Florida soybean crops and hope to go statewide eventually. (IPM computer programs are currently being set up in most US land-grant universities).
* Research to collect information for an IPM program for forest pests was recently begun. Included in the effort are the International Biological Program's study of coniferous bark beetles and the USDA's expanded research on the gypsy moth, Douglas fir moth, and pine beetle.
* Pilot studies on rangeland IPM programs are being done by the Science and Education Administration of the USDA in Nevada and New Mexico.
* At the Georgia Coastal Plain Experiment Station at Tifton, teams from the US Department of Agriculture (USDA) and University of Georgia are studying IPM with intensive cropping sequences (using more than one crop per year on the same land). Crops include corn, peanuts, soybeans, as well as many vegetables from the Southeastern US.
Beyond the new emphasis on scientific integration of techniques, the CAST report notes another development - the interest of the non-farming public in pest management. This is largely attributed to public concern over health hazards associated with chemicals.
IPM methods include the use of chemicals, use of a pest's natural enemies, genetic changes to produce pest-resistant plants or decrease the pest's effectiveness, a variety of tilling practices, and preventive measures such as better sanitation and early detection.
According to Dr. Turpin, attitudes are a major obstacle to reducing the use of chemical pest control.
''People want instant solutions,'' he says. ''The farmer wants to make a profit; the homeowner wants an aesthetic and comfortable environment . . . . Chemical spraying provides that.''
Dr. Turpin, along with many other agricultural specialists, readily give chemicals a place in IPM programs. But they, along with the environmentalists, would like to reduce the level of use as much as possible.
Not all IPM advocates, however, feel this way.
Dr. Gideon Hill, of the E.I. duPont de Nemours chemical company in Wilmington , Del., believes weed control with pesticides is ''the hub'' of IPM. ''If herbicides were not available, almost one-third of the total annual production of our major crops would be lost, at a value of $13 billion,'' he says.
Despite the feeling that chemicals are indispensable to a successful IPM program, experiments are beginning to show otherwise--at least for some crops. An IPM strategy set up in 1976 for cotton crops in the Trans Pecos region of Texas included no chemical pesticides. Within a year the yield had increased, per-acre production costs were cut, and farmers' profits increased.
One of the reasons for blanket applications of chemicals instead of using a combination of methods is that chemical use is constantly reinforced by the pesticide industry, says Dr. Turpin.
''For instance, the February 20 issue of the semi-monthly Indiana Prairie Farmer contained 12 pages of full-color ads promoting rootworm insecticides and nothing on alternative strategies and tactics,'' notes Dr. Turpin. Why this imbalance? ''Because there are dollars to be made from pesticides and nothing to be made from simple crop rotation (if that's all that's required)--to anyone other than the farmer,'' he says.
The main need, on which Dr. Hill and Dr. Turpin agree, is education. People need to be aware of both the problems and the alternatives, they say. Observes Dr. Turpin: ''IPM is really a philosophy, a whole way of thinking. It's not a set program all ready to go. It depends on what's involved. It's easier and more profitable to market a bag of pesticides than it is a new approach.''