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Biopesticides' Potential Aided by U.S.-Mexico TeamworkBy Ben Hardin
June 5, 1998
New technology could help viruses, bacteria and other environmentally friendly biopesticides compete with traditional chemical pesticides. Agricultural Research Service scientists and cooperators in Mexico have produced improved formulations that feature economy, reliability and user-friendliness.
Called microencapsulation, the technology involves mixing microbes with a matrix-forming material, such as cornstarch that has been heated, or partially gelatinized, to enable water absorption. When the mixture is added to water and dried, the microbes become entrapped in tiny protective particles. Resuspended in water, the particles can be applied to crops using conventional spray equipment.
The bacterium Bacillus thuringiensis (Bt) and baculoviruses--a group of viruses that cause disease in caterpillars--are microbes that were microencapsulated at the National Center for Agricultural Utilization Research, Peoria, Ill. The latest research may help establish alternatives to relying on chemical insecticides or transgenic insect toxins that are now in a few crops.
Until now it's been difficult to market encapsulated biopesticides because there was no single formulation appropriate for different crops and field-spraying equipment. The amount of ingredients such as sun protectants added to boost a formulation's effectiveness depended on how much water was needed for the mix.
With the new technology, these ingredients--called adjuvants--are mixed into formulations as they are manufactured. The adjuvants are uniformly bonded with starch and the biopesticide, remaining stable throughout conventional tank mixing and application.
The research was an outgrowth of participation of ARS scientists in biotechnology workshops for Mexican academia and industry. More details can be found in the June issue of Agricultural Research magazine. The story also is on the World Wide Web at:
Scientific contact: Michael R. McGuire, ARS, National Center for Agricultural Utilization Research, Peoria, Ill., phone (309) 681-6595, fax (309) 681-6693, email@example.com.