番茄根部常结砣一般是由番茄根结线虫病为害所致。该病在温室、大棚和露地等番茄上均都有发生,温室栽培可四季发病,一般发病的温室可造成损失20%~30%,严重的损失达60%~70%,甚至绝收。除危害番茄外,还能危害茄子、黄瓜、莴苣、菜豆、芹菜、辣椒、甘蓝、大白菜等。一般土温25~30℃,土壤持水量40%~70%,病原线虫发育非常快。地势高燥、土质疏松,湿度适当,盐份低及连作地发病重。温室重于露地。一、发病症状根部:幼虫在根内刺激幼根膨大成瘤状, Tomato root knot usually caused by tomato root knot nematode disease. The disease occurs in greenhouses, greenhouses and open-field tomatoes. Greenhouse cultivation can occur in all seasons. Generally, greenhouse diseases can cause losses of 20% to 30% and severe losses of up to 60% to 70%. In addition to endangering tomatoes, but also endanger eggplant, cucumber, lettuce, beans, celery, pepper, cabbage, cabbage and so on. General soil temperature 25 ~ 30 ℃, soil water content of 40% to 70%, pathogenic nematode development is very fast. High terrain, loose soil, appropriate humidity, salt and even low incidence of severe disease. The greenhouse is heavier than the open field. First, the onset symptoms root: larvae in the root to stimulate the root enlargement into the tumor,