容县从1960年开始栽培稻底绿肥,据这几年观察,红花草以白粉病为害的面积最大,损失也最严重。在生长期中罹病的,植株矮小,鲜苗一般减产20—30%,严重的达50%左右;在生育后期罹病的,荚果少,秕粒多,种子一般减产25—30%,严重的减产60%左右。白粉病初起时,先在田垌中个别田块形成一窝窝的发病中心,象在叶面上撒上一层 Yung County from the beginning of cultivation of rice at the end of 1960 green manure, it has been observed in recent years, safflower grass powdery mildew damage the largest area, the loss is also the most serious. Diseases in the growing season, the plant is short, the general reduction of 20-30% of fresh seedlings, a serious problem of up to about 50%; in the late growth of disease, less pods, more grains, the seeds generally 25-30% reduction in production, serious yield About 60%. When the powdery mildew begins, the center of the disease is formed in a few litters in the fields. As a sprinkle on the leaves,