The fungal disease blast caused by Pyricularia oryzae and sheath blight disease caused by Rhizoctonia solani are major diseases of rice in Thailand. Recently emerging of dirty panicle disease is contributing to an additional challenge to the rice disease panorama. Dependence on fungicidal sprays for disease control adds expense to farmers and contributes to non-target damage from fungicides employed. No single rice variety has high levels of genetic resistance to all major rice diseases. Because of these challenges and gaps in the disease management strategy, integrated disease management that employs biological control measure is becoming increasingly attractive for rice producers. Biological control product formulated based upon Bacillus megaterium has been produced and tested in the rice field for its ability to control blast and sheath blight. During off season rice testing in Uttaradit province, Thailand, water-soluble
granules showed a high level of disease efficacy for controlling sheath blight, rice blast and dirty panicle disease. Applications were made as a seed treatment once (at 1 g formulation/100 g seed), followed by 3 sprays at the seedling, tillering and flowering stages. The application rate was 200 g formulation/20 L water/rai application rate. The water-soluble granules of B. megaterium show potential to increase yield of rice when weed populations are kept under control thresholds and recommended amount of N-fertilizer was applied. Besides the results with the 3 aforementioned diseases, this biological control option has selected to be tested for neck blast (P. oryzae) efficacy. Testing results are being disseminated to local and regional farmers who are interested to produce rice organically and reduce their fungicide use.