Rice blast disease is one of the most devastating diseases in India that causes major grain yield losses in farm fields. It is a fungal disease caused by Pyricularia oryzae (sexual stage is Magnaporthe grisea). The disease occurs worldwide where paddy is grown but the severity varies based on the location and environmental conditions. The disease infects all parts of the plant except roots but the severity is high on leaves, nodes and panicles (neck). Leaf blast fungus produces spindle shaped lesions with grey centre and dark brown margins that further reduces the net photosynthetic rate of individual leaf. In infected nodes, irregular black areas encircle the nodes breaking up all the plant parts above the infected nodes. In neck blast, fungus attacks the peduncle during the flower emergence stage and the lesions turns to brownish black resulting in poor or low grain filling. India is reported to encounter 5 to 10% yield losses only due to neck blast.
To control the blast disease, there are lot of synthetic and organic fungicides available
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