根结线虫病是烟草的主要病害,常年产量损失10％,重病年损失20％,重病因植株矮化,叶片变黄至枯焦,几乎无收。该病在四川年发生5—8代,每代20—30天,雄虫极少、孤雌生殖,1个雌虫可产卵2000粒,释放入土壤10—20厘米土层。因此,该线虫繁殖快,防治极为因难。若普遍采用药剂防治,必然加大投入和严重污染农田。若在大田期发现烟叶褪绿变黄,则已成为不治之症。为此,利用指示植物预测土中有无根结线虫,有虫数量多少,可有的放矢指导防治。一、应用原理根结线虫浸入植物幼根后,使受害幼根细 Root-knot nematode disease is the main disease of tobacco, perennial production loss of 10%, severe illness, 20% loss, severe disease due to dwarf plants, leaves yellow to dry coke, almost no income. The disease occurred in Sichuan in 5-8 generations, each generation 20-30 days, very few male, parthenogenesis, a female can spawn 2000, released into the soil 10-20 cm soil layer. Therefore, the nematode multiply fast, prevention is extremely difficult. If the general use of chemical control, will inevitably increase investment and serious pollution of farmland. If found in the field of tobacco leaf fade yellow, it has become incurable disease. To this end, the use of indicator plants in the soil to predict whether there is no root-knot nematode, the number of insects, there may be targeted guidance and prevention. First, the application principle root knot nematode immersed in plant roots, the victims of fine root fine