Side effects of some herbicides to Fusarium moniliforme and its antagonistic microorganisms

Abstract

Forty six isolates of fungi and forty isolate of bacteria were isolated from sugarcane field soil, Kasetsart University, Kamphaengsaen Campus in 1986-88 by spreading soil suspension on selected media, Marin’s medium and Nutrient agar. The dominant isolate of soil microorganisms were Aspergillus spp. And gram negative bacteria. Eight isolates of those fungi showed the antagonistic effect to Fusarrium moniliforme namely A. niger, A. flavus isolate 1 and 2 , A. fumigatus, A. tamarii, Curvalaria sp. Isolate 1 and 2, and Trichoderma sp., where two isolates of gram negative and two isolates of gram positive bacteria were included. The inhibitory effect of herbicides, atrazine, ametryn and paraquat, to F. moniliforme and its antagonists was tested by poisoned food tcchnique on PDA and CO₂ production of herbicide treated soil in anaerobic condition. Ametryn showed the best inhibitory effect to F. moniliforme. All antagonistic fungi were inhibited by atrazine whereas slightly effect was founded in paraquat and ametryn treatment. Highly inhibitory effect to herbicide to all isolates of antagonistic bacteria was observed in paraquat treatment.