在培育山茶花时,有时会遇到这样的现象:地上部既没有发现害虫为害,又没有什么病害症状,但植株生长衰弱,继而叶、茎全株枯黄而死亡。如果把植株拔起,用放大镜细看,根部有大小不等的瘤状物(虫瘿),小的如菜籽,大的似黄豆,有的根瘤腐烂破裂,病根颜色变深褐色,主根膨大无须根,有的主侧根呈畸形,末端比前端粗,这就是根结线虫病。 In the cultivation of camellia, sometimes encountered such a phenomenon: the ground has found neither pest damage, but also no symptoms of disease, but plant growth and weakness, followed by leaves, stems and whole plants yellow and died. If the plant uprooted with a magnifying glass, the root size ranging from the tumor (insect), small, such as rapeseed, big like soybeans, some rupture of root nodules, roots dark brown color, the main root swollen No root, and some main lateral root deformity, the end is thicker than the front, which is the root knot nematode disease.