ASPERGILLUS-PARASITICUS GROWTH AND AFLATOXIN SYNTHESIS ON FLORUNNER PEANUTS GROWN IN GYPSUM-SUPPLEMENTED SOIL

Five levels of gypsum supplementation (0, 550, 1100, 2200, and 4400 kg ha-1) were applied to peanut fields 35 d after planting. After the gr owing season, peanuts were harvested, ground, and inoculated with 1 x 10(7) Aspergillus parasiticus (NRRL 5139) conidia. After 14 d at 25-de grees-C, aflatoxin was extracted and quantified by thin-layer chromato graphy. Fungal growth was assayed using a modified chitin assay. Peanu ts from gypsum-supplemented fields at each level of supplementation su pported significantly less aflatoxin production when compared to contr ol peanuts (no calcium supplementation). Results from the chitin assay showed a decrease in fungal biomass which correlated with the decreas ed aflatoxin synthesis.