Combination Of Nitenpyram And Pymetrozine To Protect Tomato From Bemisia Tabaci

In recent years, vegetables, cotton and other crops acreage expanded rapidly, so that thestructure of a single planting, irrational industrial structure is not conducive to the control ofpests and diseases outbreaks. Especially Bt cotton in large scale, also contributed to theoccurrence of whitefly. Annual crop cultivation and cropping provide rich diets as whitefly,greenhouse whitefly provided in the temperate and boreal ideal place to escape the cold, LiuShusheng et al (2007) research pointed out that the long-term, a large, one-sided use of asingle chemical pesticides, leading to rapid population whitefly resistance to the formationand development, and ultimately difficult to control outbreaks.In order to effectively control whitefly, ease resistance, this article on these two agentswith a single agent and complex pharmaceutical tomato greenhouse whitefly control effectswere studied. And further on the optimal spraying conditions were optimized sexualexploration.The results showed that:1Nitenpyram10%agent LD50of2.98g, while Pymetrozine was0.713g. Both agentshave shown a strong toxic effect on whitefly.2assay performed using interactive Nitenpyram and Pymetrozine different proportionsof toxic effect on whitefly mortality ratio is the highest Nitenpyram and Pymetrozine60:40compound, death rate reached68.5%of total toxicity factor of44.4, synergy is obvious.3selection of2.1%nitenpyram-EC filter pymetrozine best spraying conditions, theresults show that regardless of how the application time, the higher the temperature, thelower the relative humidity, the higher control effect. This result may be due to Bemisiatabaci and dried under high temperature environment becomes active, thereby increasing thearea of contact with the medicament. Morning spraying can play in promoting the role ofagents. This result may be related with the illumination. During the day, the light cycleimpact whitefly become more active at night, so that in the morning than in the eveningspraying pesticide control efficiency is higher. The theoretical prediction (Table3-4), theoptimal solution is35degrees Celsius, most air drying, spraying in the morning, reached 104.388%control efficiency theory. However, since the temperature suitable for the growthof tomato was25degrees Celsius, and therefore, at this temperature is actually sprayedreasonable. Fixed temperature parameter is25, solve for the optimal solution for the relativeair humidity of45%, spraying in the morning, the theoretical efficiency of82.03percentanti.4under the best conditions and reasonable spraying of anti-mix effect between the agentand other agents to compare. As can be seen from the test results,2.1%Nitenpyram-Pymetrozine EC control efficiency (81.95%) is higher than the two agents (thiamethoxam25%WDG75.6%avermectin1.8%EC is70.85%).Taking these results it can be seen, nitenpyram and pymetrozine compound can increaseefficacy, thereby reducing costs. The study for the prevention of greenhouse tomato whiteflyprovide valuable information theory and practice.