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一、甜菜白粉病 甜菜白粉病遍布新疆各甜菜区,是我区甜菜的主要病害之一,甜菜中后期罹病率达80—100％。它除侵染根部外,还侵染叶茎和种球,轻者叶片密布白色粉状霉层,影响光合作用,降低甜菜含糖量和种子产量;重者植株生长缓慢以至停滞,茎叶变黄凋枯,严重降低块根和种子产量。 病原及侵染:甜菜白粉病菌主要以闭囊壳附于甜菜残茎枯叶、母根、种球上越冬。闭囊壳于发病后15—20天开始产生,初为黄色,后变黑色,八月中下旬大量形成,八月下旬卽有子囊孢子。翌年春天,闭囊壳释放子囊孢子,初次侵染采种甜菜,再过5—15天,侵染一年生甜菜,并产生大量分生孢子,分生孢子借气流传播,进行再侵染。
First, beet powdery mildew Powdery mildew throughout Xinjiang sugar beet area, beet is one of the major diseases in our region, beet in the late morbidity rate of 80-100%. In addition to infecting the roots, it also invades the stems and bulbs, the light leaves are densely covered with white powdery mildew layer, affecting photosynthesis and reducing the sugar content and seed yield of sugar beet. In severe cases, the plants grow slowly or even stagnate, Withered yellow, seriously reducing the yield of roots and seeds. Pathogen and infection: beet powdery mildew mainly attached to the shell of the beet stump leaves, mother roots, bulbs overwintering. Closure of the capsule begins 15-20 days after the onset of the disease, initially yellow, then black, a large number of mid to late August formation, asymptomatic ascospores in late August. In the spring of next year, the ascospore was released from the closed shell and the beet was first inoculated. After another 5 to 15 days, the annual beet was infected and a large number of conidia were produced. The conidia were re-infested by air flow.