Tolerance Levels of Peanut Varieties against Aspergillus flavus Infection

Peanuts (Arachis hypogaea L.) are usually infected by Aspergillus flavus and A. parasiticus during pre and post-harvest periods subsequently resulting in aflatoxin contamination. Thirteen peanut varieties were evaluated for kernel and pod colonization and infection by A. flavus in this study. The pods and kernels were examined under a microscope for A. flavus infection levels. Differences in mean ratings of infected peanut kernels and pods were observed after 10 days of artificial inoculation and incubation. More differences were observed among the mean ratings of peanut kernels and pods with invisible mycelial surface coverage. However, these mean differences were not statistically significant P ≥ 5. Peanut varieties with the biggest mean ratings of kernels and pods with invisible mycelia or no visible sign of infection and smallest mean ratings of infected pods and kernels could be considered tolerant to A. flavus colonization and infection in this study. Therefore, there is a need to promote the cultivation of these varieties by farmers as they have low levels of infection and subsequently low level of aflatoxin contamination. The peanut varieties with the lowest mean ratings of kernels and pods with invisible mycelia which are considered to have good attributes warrant improvement through selection and breeding. This is because most farmers in Uganda store their peanuts in pod form which offers some protection against infection. In addition, peanut varieties with biggest mean ratings of kernels with invisible mycelia need to be promoted among traders since they are considered to have lower levels of A. flavus infection.