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.