1大豆霜霉病为害程度霜霉病除为害大豆幼苗和叶片外,更重要的是种子带菌。病种子的发病率为10%～50%。百粒重减轻4%～16%重者可达30%。病种子发芽率下降10%以上,含油量减少0.6%～1.2%,出油率降低2.7%～7.6%。由于霜霉病的为害,病叶早落,大豆产量和品质下降,可减产8.0%～15.2%。 1 soybean downy mildew degree Downy mildew in addition to damage soybean seedlings and leaves, the more important is the seed carrier. The incidence of diseased seeds is 10% ~ 50%. 100 weight loss 4% to 16% weight up to 30%. Seed germination rate of the disease decreased by more than 10%, oil content decreased by 0.6% to 1.2%, the oil yield decreased by 2.7% to 7.6%. Due to downy mildew damage, sick leaves early fall, soybean yield and quality decline, can cut 8.0% to 15.2%.