At first, blast disease was known as one of the main problems in upland rice, but since the late 1980s, this disease has also been found in irrigated rice. The disease which can reduce the yield huge is caused by the pathogenic fungus Pyricularia grisae.
Blast disease causes two characteristic symptoms, namely leaf blast and neck blast. Leaf blast is a blackish-brown spot with a white center spot, rhombic in shape. In contrast, the neck blast is a blackish-brown spot at the base of the neck, which can cause the panicle neck to be unable to support the panicle and break. The ability of pathogens to form strains quickly makes controlling this disease very difficult.
This disease is controlled by alternately planting resistant varieties to anticipate rapid changes in the blast race and proper NPK fertilization. Planting at the right time and seed treatment can also be pursued. If necessary, use a fungicide with the active ingredient methyl thiofanate, fosdifen, or kasugamycin.
Source: Putra, R. (2018). Hama dan penyakit tanaman padi dan deskripsi padi sawah. Balai Pengkajian Teknologi Pertanian Kepulauan Riau.