Airborne fungal load in agricultural environment during threshing operations.

The effect of threshing operations on the fungal spora of farm air, has been studied with the culture plate method. Air samples were taken before, during and after the threshing of paddy and wheat grains, at the end of the respective crop seasons. An immediate local increase in the airborne fungal load was observed during threshing operations. In case of wheat the high rise was due to Alternaria tenuissima, followed by Drechslera sp. and Cladosporium herbarum. In 'Boro' variety of paddy, the high count was contributed by Alternaria humicola and A. tenuissima, while in 'Aman' variety, Helminthosporium oryzae was the dominant type followed by C. herbarum and unidentified yeasts. Aspergillus spp. were observed in significant numbers before the operation started; their occurrence was negligible during threshing. A considerable number of yeast was observed, particularly during threshing and after threshing operations.