DEVELOPMENT OF ASPERGILLUS MOLDS IN LITTER FROM PISTACHIO TREES

Aspergillus molds frequently infested, infested, and sporulated on pis tachio litter such as fallen pistachio fruit and male inflorescences t hroughout summer in commercial pistachio orchards in California. A. ni ger was isolated much more frequently from pistachio litter than any o ther species, but the aflatoxin producers, A. flavus and A. parasiticu s, also developed in pistachio litter. Two distinct strains of A. flav us were isolated: strain L (a few large sclerotia) and strain S (abund ant small sclerotia). Strain L occurred substantially more often than strain S. All isolates of strain S and A. parasiticus were aflatoxin p roduces, but only 43% of the isolates of strain L produced aflatoxins. Other species isolated in the subgenus Circumdati were A. tamarii, A. melleus, A. ochraceus, A. japonicus, and A. wentii. The development o f Aspergillus molds in pistachio litter could increase the amount of A spergillus inoculum in the orchard, resulting in greater numbers of mo ldy and mycotoxin-contaminated pistachio nuts.