1大豆紫斑病主要为害豆荚和豆粒,也为害叶和茎。苗期染病,子叶上产生褐色至赤褐色圆形斑,云纹状。真叶染病初生紫色圆形小点,散生,扩展后形成多角形褐色或浅灰色斑。茎秆染病形成长条状或梭形红褐色斑,严重的整个茎秆变成黑紫色,上生稀疏的灰黑色霉层。1.1危害症状豆荚染病病斑圆形或不规则形,病斑较大,灰黑色,边缘不明显,干后变黑,病荚内层生不规则形紫色斑,内浅外深。豆粒染病形状不定,大小不一,仅限于种皮,不深入内 1 soybean purple spot disease mainly pods and beans, but also damage leaves and stems. Seedling disease, cotyledons produce brown to brownish brown spot, moire. True leaf disease purple new round dots, loose, expanded to form polygonal brown or light gray spots. Stems grow into strips or fusca-like brownish-brown spots, and the entire severely stalk becomes dark-purple and sparse gray-black moldy. 1.1 Harmful symptoms pods infected spots circular or irregular shape, lesion larger, gray-black, the edge is not obvious, dry black, sick pods irregularly shaped inner purple spots, the shallow depth. Pea ill shape, size, limited to the seed coat, not deep inside