生物熏蒸用于治理蔬菜根结线虫病的研究

将甘蓝(Brassica oleracea)、芥菜(B.juncea)和雪里蕻(B.junceavar.multiceps)的叶及芥菜疙瘩(B.napifor-mis)的块根组织以3.5 kg/m²的量分别施入密封于棉纱缸中的严重感染根结线虫(Meloidogyne incognita)的土壤中,在25℃和32℃下熏蒸6 d后对活体线虫的测定结果表明,在25℃下用上述4种材料熏蒸后活体线虫数量分别比对照减少80%、85%、87%和91%。32℃下的熏蒸效果明显优于25℃下的熏蒸效果,各处理土壤中均未发现活体线虫,而无处理对照土壤中的活体线虫数量为1 540条/kg土壤。对各类添加物增效作用的调查结果表明,添加麦麸的增效作用最明显。田间试验结果表明,植物材料单独或与添加物混合使用对根结线虫病的防效均显著高于太阳能和土壤还原消毒法的防效。其中芥菜添加麦麸在开花期和盛果期的防效分别为65.2%和66.0%,与对照药剂98%棉隆可湿性粉剂的防效无显著差异;各植物材料熏蒸效果大小依次为芥菜>雪里蕻>芥菜疙瘩>甘蓝。

Soil biofumigation for management of vegetable root-knot nematode disease

It is of great significance to develop soil biofumigation technique for management of vegetable root-knot nematode disease(Meloidogyne incognita) occurring seriously in China and therefore reduction of methyl bromide usage.Leaf materials of Brassica oleracea,B.juncea and B.juncea var.multiceps,and root tissue of B.napiformis were applied at 3.5 kg/m² separately into seriously nematode-infested soil contained in cotton yarn jars.After 6 days of incubation of the mixture at 25 ℃ and 32 ℃,living nematodes remained in the incubated soil were accounted.The results indicated that fumigation with these 4 plant materials at 25 ℃ could reduce nematode population by 80%,85%,87% and 91%,respectively,in comparison with control.Fumigation at 32 ℃ with all of the materials tested resulted in death of all nematodes in soil,versus 1 540 nematode/kg of soil survived in untreated soil,indicating a higher effect at 32 ℃ than at 25 ℃.Investigation of fumigation improvement by various amendments showed that wheat bran could significantly increase the effect of fumigation.Field trials demonstrated that fumigation with brassica materials and mixture of the materials with amendments reduced tomato root-knot disease by 65.2% and 66.0% at blossom and fruiting periods,respectively,which was higher than that by solarization and reducing rodex potential of soil,and not significantly different from that by fumigation with dazomet,a widely used chemical fumigant in China.The most effective fumigation brassica source was B.juncea,followed by B.juncea var.multiceps,B.napiformis and B.oleracea.