近年来梨树生产发展很快,但伴随着新品种的引进,出现了一些以前很少出现的病害,其中黄金梨的“黄头病”和水晶梨萼洼黑斑病,就是新近发现影响梨出口质量的两种较难防治的病害。1.黄金梨的“黄头病”(硬头病):发病的果实顶部有一层厚约0.5～1.5毫米,硬度很大,黄白色的环斑,除色 In recent years, pear production has developed rapidly, but with the introduction of new varieties, there have been some diseases rarely seen before, of which the “yellow head” of Golden Pear and Crystal Pear calyx black spot is the newly discovered pear Export quality of the two more difficult to control the disease. 1. Golden pear “yellow head disease” (hard head disease): the incidence of the top of the fruit has a layer of about 0.5 to 1.5 mm thick, yellow and white ring spot, in addition to color