title: Interaction of water with three granular biopesticide formulations.
abstract: Two obstacles for biopesticide commercialization, long shelf life and reliable efficacy, are both affected by moisture availability. Three biopesticide delivery systems, TRE-G, PEC-G, and PESTA, were analyzed by dynamic vapor sorption analysis. The objective was to investigate the moisture sorption profile of each system in air at 25 degrees C and a relative humidity (RH) ranging from 0 to 90%. The formulations sorbed up to 12.7% moisture. In rehydrating from 0.00 to 90% RH, TRE-G and PEC-G were >or=63% and >or=58% faster than Pesta, respectively. In losing moisture from 90 to 0.00% RH, Pesta was 3.4 and 2.3 times slower than TRE-G and PEC-G, respectively. The GAB model was inadequate for describing moisture sorption, but the Young and Nelson model showed good correlation (r > 0.990) for all three formulations. Moisture distribution for all formulations was obtained. The implications of the findings as they relate to shelf life and dew period requirements of biopesticides are discussed.
authors.affiliation: Application and Production Technology and Biological Control of Pests Research Units, Agricultural Research Service, US Department of Agriculture, Stoneville, Mississippi 38776, USA. Margaret.Lyn@ars.usda.gov
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Lyn
authors.forename: Dan
authors.initials: D
authors.lastname: Burnett
authors.forename: Armando R
authors.initials: AR
authors.lastname: Garcia
authors.forename: Ron
authors.initials: R
authors.lastname: Gray
mesh_terms: D000327:Adsorption; D002626:Chemistry, Pharmaceutical; D004304:Dosage Forms; D004355:Drug Stability; D010575:Pesticides / Q000737:chemistry*; D014867:Water / Q000032:analysis*
chemical_list: D004304:Dosage Forms; D010575:Pesticides; D014867:Water