Effects of Seed Coating Agents on the Occurrence of Main Pests and Maize Yield in Corn Field

Abstract

In order to clarify the influence of major neonicotinoid seed coating agents on the occurrence of important pests and plant yield in maize field,and select safe and effective seed coating agents that are suitable for controling main pests in maize field and increase maize yield,this study evaluated the effects of four flowable concentrate seed coating agents (600 g/L imidacloprid, 30% thiamethoxam,200 g/L clothianidin and 48% clothianidin·imidacloprid) on maize emergence rate,occurrence of target pests and non-target pests,and maize yield under field conditions. The results indicated that the test neonicotinoid seed coating agents had no significant effects on maize seedling emergence rate and showed a good control effect on target pests like Laodelphax striatellus,Rhopalosiphum maidis and Aphis gossypii. Furthermore, 48% clothianidin·imidacloprid FSC had the best control effect against target pests among the four test neonicotinoid seed coating agents and its control efficacies to target pests such as R. maidis and A. gossypii were still more than 90% at the later growing stage of maize. The population density of Pseudaletia separate in 30% thiamethoxam FSC treated plot at maize late filling stage and mature stage was remarkably higher than control（treated by clean water）plot,while the population density of non-target lepidopteran pests in other seed coating areas was equivalent or significantly lower than that in control plot.For the maize yield, the seed coating treated plots all increased to a certain extent when compared with the control area,and the 48% clothianidin·imidacloprid FSC treated plot increased largest with an increase rate of 10.03%. All the above results indicated that 48% clothianidin·imidacloprid FSC could be used to treat maize seeds in maize production since it not only had significant control efficacy to piercing-sucking pests through the whole growth period of maize,but also could increase the corn yield.