多年米,哈密地区梨树普遍发生一种黑斑病,其危害日趋严重。1975年,红星三场一队60亩小梨树因此病而全部死亡,100余亩人梨树也因此病而不断死枝枯叶。为此,我们于1984—1986年对此病进行了一些研究和防治试验。 1.症状 梨树地上各部位均可发病,以叶片和新梢受害最重。病初叶片上出现极小 Years of rice, pear trees in Hami area a black spot disease, the increasingly serious harm. In 1975, the Red Star three teams of 60 acres of pear so sick and all died, more than 100 acres of pear are also sick and dead leaves. To this end, we carried out some research and prevention and control trials on the disease in 1984-1986. 1. Symptoms Pear all parts of the ground disease can occur, with leaves and shoots the most affected. Very early leaves appear on the disease