| The root knot disease caused by Meloidogyne incognita is one the most important disease that have effect on the agricultural production. To the greenhouse vegetable, the lost is particularly serious. Summer squash and muskmelon are two important melon and fruit crops in greenhouse which is also the main host of M. Incognita in Shandong province. Abamectin is now the registered pesticide for control of nematodes. But its efficacies were ranged in different areas, which make the application rate and the cost often was higher. Misuse and incorrect method also caused the phytotoxicity and soil pollution. In the former study we found the nematicide and its formulation, the physico-chemical properties of soil affecting their activities. In this paper, we tested the toxicity of nematicides to 2nd-instar juvenile of M. incognita and the safety to summer squash. By the orthogonal design optimize method,the best combination of application rate of abamectin, formulation and water consumption. The main results were as follows:1. The dipping method was used to determine the lethal activity of nematicides to M. incognita J2.The LC50 of abamectin was 6.5207 mg/L, of emamectin benzoate was 3.9253 mg/Land of fosthiazate was 14.1425 mg/L.2. The treatments by abamectin all formulation and fluopyram suspension were safe to summer squash. These treatments germination rate was over 88%. But the highest germination rate of fosthiazate was not exceed 80%, its lowest germination rate is less than 50%. All the physiological indexes of plant in fosthiazate treatment were significantly lower than that of control. But the indesxes of plant in abamectin and fluopyram treatment were not significant difference with that of control. So abamectin and fluopyram are safe to summer squash. Fosthiazate inhibits the plant growth. Being use of fosthiazate to control M. incognita disease should pay attention to the dosage and application methods, the hole application is not recommended.3. The trial was carried to evaluate the variety of nematicide, formulation and application method in field in summer squash.20,40,60 days after transplanting, the number of nematode juviniles in soil of 10% fosthiazate GR,5% abamectin EC and CS treatment were significantly lower than that of control. The root knot levels of 10% fosthiazate GR treatment 5% abamectin EC and CS treatment were not significant difference. The plant height and plant vigor of 10% fosthiazate GR treatment were significantly lower than that of 5% abamectin CS and 2% Emamectin benzoate EC treatment. In the treatments by 5% abamectin EC and CS, the yield was the highest. There difference were not significant but their yields were significantly higher than that of other treatments. Control treatment had the lowest yield of weight being 4.32±0.07kg per plant.4. For optimization the application dosage, formulation of abamectin and water consumption, the the orthogonal design experiment was carried in muskmelon field. The dosage was significantly influence of the root knot level and yield. The order of the influences was dosage>water consumption>formulation. The impact on muskmelon production order were dosage>formulation= water consumption. From the main effect diagram, along with the increase in dosage of active ingredients, root knot level was becoming more and more low. The root knot level of 2000 mL of water consumption was lower than that of 1000 mL. The efficacy of 5% SC treatment was slightly below than that of 5% CS treatment. Along with the increasing in dosage of active ingredients, the muskmelon production was gradually increasing. Production at the same time, increased along with the increase in water consumption. The production of 5% abamectin CS treatment was slightly less than that of 5% abamectin SC treatment.5. The orthogonal design experiment of the factors of application dosage, formulation of abamectin and water consumption was carried in summer squash field and their economic benefit of control were also calculated. Considering cost,5% abamectin SC application of 0.03 g a.i./plant, with 2000 mL water consumption was higher than that of 0.04 g a.i./plant which of the profit was nearly 50 yuan/667m2. From the point of production,5% abamectin SC application of 0.03,0.04 g a.i./plant, with 2000 mL water consumption,5% abamectin CS application of 0.03,0.04 g a.i./plant, with 1000 mL water consumption. The production in fluopyram and abamectin EC treatment had not significantly differences. There were not significantly difference in production of the treatment by farmers, the treatment of 5% abamectin SC application of 0.02 g a.i.with 2000 mL water per plant and 5% abamectin CS application of 0.02 g a.i.with 2000 mL water per plant. But only from the point of view of input-output, that of farmers treatment was between 5% abamectin SC application of 0.01 g a.i. with 2000 mL water per plant and 5% abamectin CS application of 0.02 g a.i. with 2000 mL water per plant. Farmer’s application of abamectin diluted in the irrigation water cause the waste of pesticide.From the above results, increasing the dosage of active ingredients, increasing water consumption and using suspension were helpful to improve the control effect of abamectin in field. But take into consideration the economic benefit that when used with 5% abamectin SC, application of 0.03 g a.i./plant, with 2000 mL water consumption will have the best profit. |
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