| Diseases caused by root-knot nematode is serious on vegetable, especially in northern China, Meloidogyne incognita is one of the most pathogenic, prevalent serotypes. It's necessary to develop scientific application techniques for the improvement of nematicide utilization because of the limited nematicide. In this paper, to determent the indoor toxicity of abamectin and fosthiazate to M. incognita J2 in Tai'an's surrounding rigion and provide feasibility evidence for scientific application of abamectin in drip irrigation area, the control effect of different abamectin formulations were compared by bioassy in different applying way, also, the adsorption, leaching and distribution after drip irrigation of different formulation abamectin in soil was studied. The main results are as following:1. The sensibility of M. incognita J2 in Tai'an surrounding area to abamectin and fosthiazate was tested on the method of immersing the insects. The LC50 of abamectin to J2 in five areas were 1.7032 mg/L-4.758 mg/L after being treated for 24 h, and there was no significant difference in the sensitivity to abamectin. The LC50 of fosthiazate to J2 in five areas were 3.0277 mg/L-21.535 mg/L after being treated for 24 h, and there were little significant difference in the sensitivity to fosthiazate.2. The control effect of different abamectin formulations in different application way was tested in pot experiment, and the influence to growth targets of tomato was also tested. In the same applying way and dose, the EC has the best control effect, and the efficiency was 68.75% in the dose of 0.5 g/plant. In the same formulation and dose, the apply way of blending of soil has the best control effect. In all treatment, the lowest efficiency treatment was applying SC 0.05 g/plant by drip irrigation, it was only 11.31%. There was some influence to growth targets of tomato. The EC at high dose was inhibition of root growth, the root length of high dose treatment was inferior to the middle-dose and low dose. In addition to this, the control effect was higher and the growth targets were better.3. The adsorption, leaching and distribution after drip irrigation of different formulation abamectin in soil was studied by oscillation equilibrium experiment, column leaching, soil thin layer chromatography and indoor simulation of drip irrigation. The adsorption of different formulation abamectin in soil were well fitted by Freundlich equation, and the EC, SC, CS adsorption constants (Kd) were 177.88,76.01,55.50, and they were belong to the level of easy adsorption. On leaching properties, CS>SO?EC, but there was more than 40% abamectin concentrated in the 0-5 cm soil layer, three formulations avermectin were all belong to the difficult leaching level. On mobility performance, the CS belonged to medium level of mobile, but the EC and SC belonged to the more difficult to move. The distribution of abamectin after drip irrigation was influenced by the adsorption, leaching and moving in soil, and in addition to this, the distribution also was influenced by the formulation, water consumption, volume-weight. There was correlation between moisture diffusion and the spread of the potion, but abamectin diffusion was lag the moisture diffusion significantly. Form ANOVA of orthogonal design, the formulation, water consumption, volume-weight all has different influence to the distribution. In horizontal maximum diffusion distance, the water consumption has a greater impact, but in vertical, it was volume-weight; In horizontal effective diffusion distance, the formulation has a greater impact, but in vertical, it was volume-weight; In diffusion area, water consumption has a greater impact to maximum diffusion area, but in effective diffusion area, it was volume-weight. Therefore, to increase the diffusion area of abamectin, when applying abamectin by drip irrigation, it should be appropriate to increase the irrigation water, loose soil, choose CS or SC.4. The control effect of abamectin by drip irrigation against tomato root-knot nematode was evaluated in field. The results showed that the effect in the way of drip irrigation was lower than that of root-irrigation per plant, but in some conditions, the way of applying abamectin by drip irrigation could also achieve a certain control effect. The abamectin of EC, SC, CS formulation could achieve the effect 61.77%,64.04%,62.06% by root-irrigation per plant. The treatment 8 (formulation:EC, water consumption:1.5 L, flow rate:0.1 Mpa) and treatment 3 (formulation:EC, water consumption:2.0 L, flow rate:0.075 Mpa) could achieve the effect more than 60%. From the distribution of abamectin after applying, we could see that the distribution of abamectin by the way of root-irrigation per plant were more better than drip irrigation, and the water consumption has greater influence to effective diffusion area, and, the next was flow rate, an the formulation was the last. |
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