瓜类蔬菜如黄瓜、南瓜、苦瓜,豆类蔬菜如豇豆、菜豆,茄果类蔬菜如番茄、茄子、辣椒等在生长期闻,叶片上经常生有白粉。这些白粉开始时在叶片的正面或背面产生白色近圆形的小粉斑,随后小粉斑逐渐扩大,小粉斑也可以连成片,甚至覆盖整个叶面。这种白色粉状物就是白粉茵。白粉茵侵入叶片吸取营养,并不断地破坏菜叶内 Melons vegetables such as cucumber, pumpkin, bitter gourd, legumes such as cowpea, beans, solanaceous vegetables such as tomatoes, eggplant, peppers and other growth in the smell, the leaves are often born with white powder. These white powders initially give rise to white, almost round, small speckles on the front or back of the leaves, and then the small speckles gradually expand. Small speckles can also be lined and even cover the entire foliage. This white powder is white powder. White powder invasion of leaves absorb nutrients, and continue to destroy the leaves inside