Susceptibility of California almond cultivars to aflatoxigenic Aspergillus flavus

Colonization and sporulation of aflatoxigenic Aspergillus flavus Link on intact and injured seed was evaluated for a selection of almond (Prunus dulcis (Mill.) D.A. Webb) cultivars. Barriers to fungal development were identified at the intact seedcoat and at the seed cotyledon tissue. The seedcoat barrier was expressed as a delay in fungal colonization for up to 3 days following the inoculation of intact seed. Seedcoat resistance was uniformly high for all cultivars tested. Cotyledon resistance, which was expressed as a lower rate of disease development was identified only in the cultivars Ne Plus Ultra, Ruby, and Carrion.