Integrated management of groundnut aflatoxin contamination through host resistance and native Trichoderma species in East Hararghe, Ethiopia

Groundnut (Arachis hypogaea L., also known as peanut) is a valuable legume and cash crop in arid and semiarid regions, but aflatoxin contamination limits its quality and export value, requiring effective management throughout the value chain. For two cropping seasons this study evaluated the effect of groundnut genotypes and native Trichoderma species on aflatoxin contamination. Thirty-six treatment combinations of 12 groundnut genotypes, two native Trichoderma species, and controls, were arranged in a triple lattice design with three replications. After harvest, groundnut seed samples were analyzed for aflatoxin using high-performance liquid chromatography coupled with a fluorescence detector (HPLC-FLD). Results revealed highly significant (p < 0.0001) differences among treatments in specific aflatoxin (B1, B2, G1, and G2) and total aflatoxin concentrations. Aflatoxin contamination of untreated groundnut genotypes was the lowest in genotype BaHa-gudo (7.3-12.7 µg/kg) and the highest in Werer-961 (167.6-182.6 µg/kg). Treating groundnut genotypes with Trichoderma species reduced aflatoxin accumulation several-fold compared to control plots, and to levels below the EU's tolerable limit (4 µg/kg). Overall, the native Trichoderma species significantly reduced pre-harvest aflatoxin contamination but different groundnut genotypes responded differently. Current results confirm the potential of integrating host genotypes and bio-control for successful and sustainable aflatoxin management.