
Biopesticides' Potential Aided by
U.S.-Mexico TeamworkBy Ben Hardin June 5, 1998New 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: http://www.ars.usda.gov/is/AR/archive/jun98/team0698.htm.
Scientific contact: Michael R. McGuire, ARS,
National Center for Agricultural
Utilization Research, Peoria, Ill., phone (309) 681-6595, fax (309)
681-6693, [email protected]. U.S. Department of Agriculture | |