Occurrence and Interaction ofAspergillus flavuswith Other Fungi on Almonds

Abstract

The occurrence of the aflatoxin-producing fungi of the A. flavus group (AF) on samples from 89 locations in California USA was influenced by other fungi on the kernels. The influence of these other fungi on AF was evaluated in 1975 and 1976 in field plots. Fruit of almond cultivars. ''Milo'', ''Nonpareil'' and ''Ne Plus'' were inoculated before hull dehiscence with dry conidia of aflatoxin-producing aspergilli alone or in combination with groups of fungi (1975) or individual isolates (1976). Fungi used included yeasts, Monilinia fructicola, Ulocladium atrum, U. chartarum, Drechslera spicifera, Fusarium roseum, Rhizopus stolonifer, Cladosporium cladosporioides, Penicillium funiculosum and A. ficuum. The presence of other fungi with A. flavus or A. parasiticus generally reduced the number of isolates of AF that were recovered from hulls and kernels. Fungi requiring high moisture appeared antagonistic to AF in colonizing almond kernels. U. chartarum reduced the isolation of A. flavus most significantly.