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黄頂病在广州地区发生已有30—40年,过去只是零星发生,为害不大。但自1959年开始則发生普遍,1959年发病率为5—7％,1960年为9—17％,1961年为30—50％,1962年减少至2—3％,1963年又較严重发生,大面积的番茄也几乎全部感染,而且发病早,損失很大。本病在各种品种上的病状特点是:感病后植株顶叶叶色褪綠乃至黄化,叶片变小,叶面皺縮,中部稍凸起,边緣多向下或向上卷曲;严重时,整个叶片呈“棒状”,病株矮化,不定枝丛生。但在薯叶型的品种如“Karlik”上的病状特点則是:顶部
It has been 30-40 years since the occurrence of the disease in Guangzhou. In the past, it was only sporadic and not very harmful. But prevailed since 1959, with a prevalence of 5-7% in 1959, 9-17% in 1960, 30-50% in 1961, 2-3% in 1962 and more severe in 1963 Large areas of tomatoes are almost all infected, but the incidence of early, great loss. Pathological features of the disease in a variety of varieties are: sick plants after the top leaf color chlorotic and yellow, leaves smaller, folds shrink, the central slightly raised, the edge more downward or upward curly; serious When the entire leaves were “sticks”, diseased plants dwarfed, not branchlets clustered. However, in the potato leaf type such as “Karlik” the symptoms are: Top