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一、苹果褐斑病:又称绿缘褐斑病,各产区均有发生,是引起早期落叶的主要病害。主要危害叶片,也可危害叶柄和果实。开始发病时,多于树冠下部和内膛的叶片上产生直径0.2~0.5毫米的黑褐色小疱疹,后扩展为同心轮纹型、针芒型和混合型3种不同类型的病斑,边缘不整齐,病健界限不明显,病斑表面有黑褐色纹线和蝇粪状黑点,病部周围及叶背仍保持绿色,后期病叶变黄脱落。叶柄染病,产生黑褐色长圆形病斑,导致叶片枯死。果实发病,表面出
First, apple brown spot disease: also known as the edge of green edge spot disease, all producing areas have occurred, is the main cause of early leaf decay. The main hazard leaves, but also can harm the petiole and fruit. Beginning of onset, more than the lower part of the crown and the inner leaves of the leaf diameter of 0.2 to 0.5 mm dark brown small herpes, and later expanded to concentric round pattern, needle-Mans and mixed three different types of lesions, the edge is not Tidy, ill-health boundaries are not obvious, dark brown lines on the surface of the lesion and fly dung-like black spots, the disease around the leaves and leaves remain green, diseased leaves late yellow off. Petiole disease, resulting in dark brown oval lesions, leading to dead leaves. Fruit disease, the surface out