怎样防治苹果锈病苹果锈病又名赤星病，寄主有苹果、海棠、花红等。可为害叶片、果实和嫩枝。叶片被害，先产生黄绿色小斑，后扩大呈中央杏黄色外围黄色的圆斑，发病１—２周后病斑表面长出先为黄色后变为黑色的小粒点，并能分泌汁液，后期病斑背面稍隆起，并长出土黄色的... How to control apple rust Apple rust, also known as brown spot disease, the host of apples, begonia, bonuses and so on. Can damage leaves, fruits and twigs. The leaves were killed, the first to produce small yellowish green spots, followed by the expansion of the central yellow apricot peripheral yellow spots 1-2 weeks after the onset of lesion surface grew yellow after turning into small black particles, and secretion of juice, late disease Spot slightly bulging back and grow yellowish ...