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在火电厂周围种植大白菜的农民,常常反映:他们的菜活而不旺、包心不紧。根据科技人员的试验观察,危害大白菜生长的元凶,就是火电厂烧煤时产生的煤烟降尘。大白菜幼苗对烟尘很敏感,即使微小的降尘量——每月每平方公里3吨左右,也就是说1个月内1平方米菜地降落烟尘3克,菜苗也会受到伤害。但是,烟尘对大白菜的主要危害时期,发生在幼苗期和莲座初期,到了莲座后期和结球期影响就不大了。大白菜的受害症状,主要出现在叶形较宽而展开的第一至九片外叶上,表现为叶片显有白色斑点,叶片失绿、枯萎,向上卷缩,有的叶片因局部受害停止生长而发生扭曲。因而植株矮小,结球率低。
Farmers who plant Chinese cabbage around thermal power plants often reflect that their livelihoods are not flourishing and are not tight-lipped. According to scientific and technological personnel of the pilot observation, the culprit endangering the growth of Chinese cabbage, coal-fired power plant coal dust generated when the dust. Chinese cabbage seedlings are very sensitive to smoke and dust, even if the tiny amount of dust - 3 tons per square kilometer per month or so, that is, 1 square meter of vegetable land within 1 month to soot 3 grams, vegetable seedlings will be harmed. However, the main hazards of soot on Chinese cabbage occurred in the early seedling stage and rosette, to the late rosette and the impact of the ball is not significant. Symptoms of Chinese cabbage mainly appeared on the first to the ninth outer leaves which are wide and unfolded, showing white spots on the leaves, green leaves on the leaves, withered, curling upward, and some of the leaves were stopped due to local victims Grow and distorted. Thus plant short, low rate of the ball.