Reaction of Peanut Genotypes under Drought Stress to Aspergillus flavus and A. parasiticus1

Abstract

Abstract Seven peanut genotypes (Arachis hypogaea L.) were tested in greenhouse and microplot experiments during two consecutive years to determine peanut peg colonization by Aspergillus flavus and to determine the effect of two drought stress treatments on the susceptibility of peanut shells and kernels to Aspergillus colonization and aflatoxin contamination. Moisture tensions within the soil and temperatures of the soil and air were monitored during these experiments. Colonization of peanut pegs was inconsistent among genotypes and between years. In general, low soil moisture tension enhanced colonization of peanut shells and kernels. Shells of most genotypes were highly colonized after harvest from each moisture regime. Kernels of all genotypes were more susceptible to A. flavus and A. parasiticus colonization under both long and short drought stress conditions compared to non-stressed conditions. However, no significant differences were obtained in the degree of Aspergillus infestation of kernels from PI 337409, Starr, and J-11 in the greenhouse experiments. Under microplot conditions, acomparison of several genotypes revealed that kernels from plants of genotypes TX811956 and TX798736 (short stress treatments) contained significantly lower Aspergillus infestation and kernels from the genotypes PI 337409 and TX811956 and TX798736 contained significantly less aflatoxin.