Effects of Imidacloprid Seed Dressing on the Seed Activity and the Seedling Growth of Maize

By the sand bioassay experiment,the effects of imidacloprid seed dressing on the seed germination and seedling growth of maize were studied.The results indicated that,compared with the contrast experiment(treatment without pesticides),all the treatments ware safe to the maize seed germination and seedling growth in the temperature of 28,5∶10 000 ratio seed coating agent increased the seedling height,primary root length,secondary root numbers, leaf numbers,area of primary leaf,fresh mass,dry mass,shoot ratio and chlorophyll content by 1.18 cm,2.85 cm, 0.35,0.28,0.74 cm2,0.41 g,0.055 g,0.220 and 11.1%,respectively.The effect was better than that tested on other treatment.In seed vigor study it showed that 5∶10 000 ratio seed coating agent increased the germination,germination rate,germination index,vigor index by 38.9%,6.4%,27.6% and 76.2%,respectively.The change was similar to activity of α-amylase after treated by different treatment in the process of maize seed germination,activity of α-amylase can still maintain a high level after 7 days treated by high pesticide and seed mass ratio,while the low ratio and the contrast decreased.With the germination days,the content of soluble reducing sugar increased,and it reduced after 7 days,but the content remain at a high level after seed dressing treatment.