梨树黑星病是梨树上发生最严重的一种病害。梢、叶、花、果都能感染。尤其果实被感染后,果型变小,呈畸形,味苦,有黑疤。严重时,失去食用价值。梨黑星病症状是:被害芽鳞片不易脱落,芽基先变黄白色,接着出现墨绿色霉状物。嫩叶感病后,生霉很快,叶部病斑多发生于背面叶脉部位,叶脉的一小段枯死并有黑霉,病斑过多时,叶片脱落。结果,大树往往因病重,早期落叶而引 Pear scab is the most serious disease in pear trees. Tips, leaves, flowers, fruit can be infected. In particular, the fruit is infected, the fruit smaller, was deformed, bitter, with black scars. In serious cases, loss of food value. Pear scytacosis symptoms are: the victim bud scales is not easy to fall off, the first yellow-white bud, then dark green mildew. Young leaves susceptible, mold quickly, leaf lesions occur in the back of the venous part of the veins a small dead and with black mold, excessive lesions, the leaves fall off. As a result, trees tend to lead to sickness and early deciduous leaves