The Mechanism And Effects Of Marigold Spinosad ⅡWater Emulsion To Prevent Watermelon Wilt

The main content of this article is the study of the mechanism and pharmacodynamic of Marigold bactericidin water emulsions Ⅱ,a kind of phytoncide, to prevent and control the watermelon wilt disease. This study provide a theoretical basis for the production of the renewable new pesticides which are broad-spectrum antimicrobial,no obvious vertebrate toxicity or phytotoxicity, rapid degradation and pollution free to environment.This paper demonstrate the results from three aspects:(1)The effect of Marigold spinosad Ⅱ water emulsion to watermelon Fusarium growth indicators and infectivity;(2)The effect of Marigold spinosad Ⅱ water emulsion to watermelon plant photosynthesis, respiration, nitrogen metabolism and resistance indicators;(3)The indoor potted plants and field plot efficacy trials of marigold spinosad Ⅱ water emulsion. The main findings are as follows:(1)Marigold spinosad Ⅱ water emulsions can kill Fusarium oxysporum effectively. While in a relatively high concentration, for example above8.0mg/mL,it is possible to kill the Fusarium oxysporum completely. The pharmacodynamic can last for240h or even longer. Marigold spinosad Ⅱ water emulsions can interfere with their breathing intensity by changing the membrane permeability to inhibit the growth of Fusarium oxysporum mycelium;(2)On the one hand, The Marigold Spinosad Ⅱ water emulsions reduce the infectivity Fusarium oxysporum by lowering the CMC cellulase and β-D-Glucosidase.On the other hand, Marigold Spinosad Ⅱ water emulsions can inhibit or even kill Fusarium oxysporum by affecting breathing intensity, interfering with energy metabolism and changing the cell membrane permeability;(3)Marigold spinosad Ⅱ water emulsions can induce the watermelon seedlings photosynthesis by enhancing performance in the chlorophyll content, increasing the acid invertase and alkaline invertase enzyme; can induce the improvement of the respiration of watermelon seedlings by increasing the activity of ascorbic acid oxidase and polyphenol oxidase; can induce the improvement of watermelon seedling nitrogen metabolism by improving performance in nitrate content and nitrate reductase; can induce the improvement of watermelon seedling resistance by increasing proline and benzenelyase ammonia enzyme levels, thereby Marigold spinosad Ⅱ water emulsions can increasse stability of watermelon membrane structure and function.(4)Through the efficacy trials on indoor potted plants and field plot, we compared marigold spinosad Ⅱ water emulsion with traditional pesticides, biocontrol agents agricultural antibiotic120, and found marigold spinosad Ⅱ water emulsion have better prevention and treatment effect on watermelon wilt and the occurance of watermelon wilt.From the results, we can see that Marigold bactericidin water emulsions Ⅱ can kill Fusarium oxysporum effectively to improve the resistance ability of watermelon seedlings to watermelon wilt. Marigold spinosad water emulsions Ⅱ have great control effect on watermelon wilt that provide a theoretical basis and scientific basis for the development of new watermelon wilt pesticide and its industrial production..