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一、发生情况甜菜白粉病(Erysiphe communis Grev.fbetae poteb)是本区甜菜主要病害之一.自一九五九年大面积种植甜菜以来,年年普遍严重发生,其中一九六○年严重发病者三万余亩(发病率80—100%、发病指数50%以上),占播种面积的43%,对甜菜产量和质量的影响很大.甜菜白粉病于六月底至七月中旬首先在採种甜菜上发生,至七月分始于一年生甜菜上出现.发病后蔓延极快,10—20天便可漫布全田.八月上、中旬发病率是直线上升,而达发病盛期.此时严重发病的叶片提早衰老死亡.八月下旬以后病势逐渐转缓.
I. Occurrence Erysiphe communis Gref.fbetae poteb is one of the major diseases of beet in this area, which has been widespread and serious annually since it was planted in beet in 1959. In 1960, More than 30,000 mu (incidence rate of 80-100%, disease index of more than 50%), accounting for 43% of sown area, the yield and quality of beet have a great influence on beet powdery mildew in the end of June to mid July first mining A variety of beet occurs on the annual beet until July, which is extremely rapid after the onset of the disease, spreading over the entire field in 10-20 days. The incidence in August and mid-August was plummeting and reached its peak. At this time the serious onset of the leaves premature aging death later in August after the disease gradually slowed down.