Combined Application Technology Of Avermectin And Two Fumigants Against Sourthern Root-knot Nematodes

Root-knot nematodes, Meloidogyne spp., are one of the main disease of vegetables, and can cause serious economic losses to greenhouse vegetables. Chemical control is still an important means of controlling vegetable root-knot nematodes. Methyl bromide is the most excellent soil fumigant that can control many kinds of soil diseases, but it is going to be phased out in2015because of its depleting to ozone layer. So to explore new high efficiency, low toxicity, low residue, alternative nematicides is the urgent task now. Abamectin is a kind of nerve antibiotic pesticide and possesses significant activity to various species of pests.1.8%AVM emulsifiable concentrate(EC) has been applied successfully to control plant root-knot nematodes. Chloropicrin and dazomet have been commercialized as methyl bromide chemcial substitutes to kill soil root-knot nematodes. This research evaluated control effect of the mixture of avermectin and chloropicrin (AVM+PIC), and the mixture of avermectin and dazomet (AVM+DZ) on root-knot nematodes to provide scientific basis for further exploration and utilization of two group of mixed pesticides.The results were as follows:l.The tested avermectin+chloropicrin in bioassay exhibited excellent control effect on the southern root-knot nematodes by chambers fumigation and concave slide fumigation. Four tested AVM+PIC possessed positive synergistic activity against root-knot nematodes with the corrected mortality being from85%to92.93%by using the method chambers fumigation. The corrected mortality of the four tested AVM+PIC was from93.81%to95.34%to root-knot nematodes by concave slide fumigation. AVM+DZ (Avermectin+dazomet) displayed positive synergistic activity aganist the root-knot nematodes with the corrected mortality ranging from77.95%to86.72%. These results imply that AVM+PIC and AVM+DZ should be studied to implode as a potential nematicide that replaced chemical nematicides and fumigants.2. Field trials of avermectin+chloropicrin and avermectin+dazomet were carried out to control cucumber root-knot nematodes in shouguang, Shangdong province. The combination of AVM+PIC and AVM+DZ exhibited excellent control effect on soil root-knot nematodes, and had general control efficacy on soil pathogenic fungus. The combination treatments displayed similar results with methyl bromide on plant height, cucumber yield and economic benifits. All of the treatments were significantly better than the non-treated control. In words, the combination of AVM+PIC and AVM+DZ performed good in every aspects, and were.recommended for practical production.In conclusion, combination of AVM+PIC(at0.009+20g a.i./m2) and AVM+DZ(at0.009+25g a.i./m2) performe good in nematodes control, soil pathogenic fungus control, plant height, cucumber yield and economic benifits, the combination treatments are recommended for controlling cucumber soil diseases. The recommended methods are as follws:AVM is appiled by spraying, follwed either by PIC applied by manual injection or by DZ applied by mixing soil, then plowing and mixing soil, finally laying out barrier sheets.