Hamed K. Abbas
USDA-ARS, USA
Title: Bioplastic formulations for the delivery of beneficial microbes to control agricultural pests
Biography
Biography: Hamed K. Abbas
Abstract
Biocontrol agents are beneficial microbes used to control agricultural pests including fungi, insects, weeds, and bacteria. Their efficacy depends on effective formulations and delivery systems to facilitate production, maintain viability during storage, facilitate field application and enhance effectiveness on crops. Starch-based bioplastics possess a number of unique properties that make them advantageous for biocontrol formulations. They are available in various forms that facilitate delivery and efficacy. In each form used, the starch component of the bioplastic plays key roles. In granule formulations, the starch-based bioplastic component enables adsorption of spore suspensions with good viability retention and provides a nutrient source for the fungus after application. In sprayable liquid formulations, the starch component allows heat-induced gelatinization of finely-divided particles, which can then deform to pass through a sprayer head, and enhance adherence to leaf surfaces, as well as providing the spore suspension adsorption and nutrient provision advantages. In seed coating, spray-coated bioplastic formulations provide a stable, adherent nutrient source with excellent dust-generation resistance and viability retention. Bioplastic granules coated with spores of non-aflatoxigenic Aspergillus flavus spread on maize (corn) field soil reduces levels of aflatoxigenic A. flavus in soil and aflatoxin contamination in harvested kernels by 97%. Biocontrol Trichoderma species in bioplastic granules reduce fungal infection of emerging roots by 85% in tomatoes, impatiens and bluegrass. Coating seeds with bioplastic containing Trichoderma species helps prevent fungal infection of roots of germinating seedlings, preventing root rot. Sprayable liquid bioplastic dispersion formulations of Beauveria bassiana significantly reduced damage caused by European corn borer in maize and tarnished plant bug in cotton, and delivered Bacillus thuringiensisendotoxin crystals to European corn borer larvae, causing 72% mortality. Bioplastic formulations have proven effective delivery vehicles for several microbial biocontrol agents in treating or preventing agriculturally-important plant diseases, but improved methods are being sought to enhance cost-effectiveness.