SEED BORNE FUNGI OF BASMATI RICE VARIETY AND TREATMENTS FOR THEIR CONTROL

Abstract

Seed samples of Basmati rice variety from Chiang Rai, Mae Tang and Mae Hea were examined by Blotter method to detect for seedborne fungi. Sixteen species in 12 genera of fungi were obtained from the test. The most frequent species found were Aspergillus spp., Trichoconis padwickii and Penicillium spp. respectively. Within the 16 species found, there were some important seedborne pathogens, for instance, Bipolaris oryzae, T. padwicki and Fusariun moniliforme. Hot water and chemical seed treatments were proposed in the test for controlling seedborne fungi. In hot water, there were included of 3 ranges of temperature treatments (50-53, 53-56 and 56-59 °C) and 3 dipping durations (5, 10 and 15 minutes). At 50-56 °C in all dipping durations, no satisfactory results of growth inhibition of important seedborne pathogens were observed. Only one treatment when dipping the seeds in 56-59 °C water for 15 min, resulted in elimination of at least six species of fungi. But hot water in the same treatment did reduce the percent of germination as high as 62%. Four fungicides namely benomyl, captan, MCB + mancozeb and mancozeb with 2 levels of concentrations were used for seed treatment in the study. MBC + mancozeb 0.5% was proved to be the best when compared with the other. All tested chemicals were good for improving the percentage of seed germination.