Management of Aflatoxigenic Fungi in Groundnut Production in Eastern Ethiopia

Aflatoxigenic fungal invasion and aflatoxin contamination of groundnut can occur during pre-harvest as well as post-harvest stages of production. Therefore, a field experiment was conducted in the 2010 cropping season with the objective of evaluating the effect of biofumigation and soil solarization on the population of Aspergillus spp. in treated soil, and to determine the effect of combined use of biofumigation and/or soil solarization and fungicide seed treatment on invasion of the crop by the fungus and its yield. The treatments consisted of solarization, biofumigation, solarization+ biofumigation and untreated control as a main plot and carbendazim, mancozeb, carbendazim + mancozeb fungicide seed treatment and untreated control as a sub-plot. The experiment was laid out as a split-plot design with three replications near Babile and Dire Dawa towns in eastern Ethiopia. Seeds of the Shulamit groundnut variety were used for the experiment The results revealed that fungal population densities in the soil were reduced drastically due to soil solarization. Integration of soil solarization + biofumigation with mancozeb + carbendazim seed treatment significantly reduced infections by A. flavus and A. parasiticus, and increased seed yield by 42.1% and 70.9% over the control treatments at Babile and Dire Dawa, respectively. Soil solarization + biofumigation in combination with fungicide seed treatments increased seed yield by up to 19.4- 42.1% at Babile and by 53-70.9% at Dire Dawa with decreased A. flavus and A. parasiticus seed infections. It could be concluded that seed treatment using carbendazim at the rate of 2 g kg-1 seed and mancozeb + carbendazim at the rate of (1+2) g kg-1 seed could be recommended as the best management option for controlling invasion of groundnut by A. flavus and for increasing the yield and quality of the crop in the region.