近年来,国家为改善生态环境,有计划的实施退耕还牧政策,草地畜牧业和草产业得到较快发展,苜蓿的种植面积不断扩大。但苜蓿病害问题越来越突出,严重影响苜蓿产量和饲料品质。在苜蓿病害中,目前尤以苜蓿立枯病发生最重。锐角分枝,分枝处有缢缩,离分枝不远处有隔膜。病菌培养至第 In recent years, in order to improve the ecological environment, the state has implemented the policy of returning farmland to grazing land in a planned way, the livestock husbandry and grass industry in grassland have been developed rapidly, and the planted area of ​​alfalfa has been constantly expanded. However, the problem of alfalfa diseases is more and more prominent, seriously affecting the yield and feed quality of alfalfa. In the alfalfa disease, especially the most serious alfalfa blight occurs. Acute angle branches, branches shrink, not far from the branches at the diaphragm. Germs were cultured to the first