纹枯病是我省水稻上主要病害之一,一般在早栽、密植及氮肥过剩的条件下易发病。发病重的稻田。叶片、稻穗、谷粒均被害,稻根逐渐变黑,导致茎叶腐烂,倒伏。受害严重的减产可达五成以上。防治水稻纹枯病的方法很多,如铲除田边杂草;加强水肥管理、重施基肥,及早追肥;避免偏施过量氮肥和未腐熟的有机肥料;前期浅水勤灌;中期及时硒田;后期干干湿湿,这些都是贫下中农从实践中总结出来的预防纹枯病的好办法。但如一旦发生了纹枯病,尤其当发病株率达5～15％时必须用药物治疗,否则就会蔓延开来,导致严重减产。防治纹枯病的药物以前常用稻脚青、稻宁粉等化学农药。这些化学农药虽然效果较好,但稻脚 Sheath blight is one of the major diseases on rice in our province. It is easy to get disease under the conditions of early planting, close planting and excess nitrogen fertilizer. The incidence of heavy rice fields. Leaves, rice, grain are killed, rice roots gradually black, resulting in stems and leaves rot, lodging. Seriously reduced yield up to 50%. Prevention and control of rice sheath blight many ways, such as the eradication of weeds in the fields; strengthen the management of water and fertilizer, heavy basal fertilizer, top dressing and early; to avoid excessive partial nitrogen fertilizer and organic fertilizer is not decomposed; shallow shallow droughts; Dry and wet, these are poor middle and lower peasants summed up from practice to prevent sheath blight a good way. However, once the sheath blight occurs, especially when the incidence rate of 5-15% of the plants must be treated with drugs, otherwise it will spread, resulting in serious yield reduction. Preventing sheath blight drugs used in the past, black rice, rice noodles and other chemical pesticides. Although these chemical pesticides better, but rice feet