Study On Absorption Difference And Mechism Of Different Pesticide In Soil By Leafy Vegetables

Leaf vegetables have vulnerable to a variety of plant diseases and pests and short growth cycle.In order to ensure the demand of vegetables,The large use of pesticides on vegetables have caused a serious problem about pesticide residues.In this paper,thiamethoxam,clothianidin,thiacloprid,acetamiprid,dinotefuran,imidacloprid and its metabolites olefinic imidacloprid,6-chloropyridine acid,5-hydroxy imidacloprid,difenoconazole was chosed as the test pesticide.The paper studied the uptake,accumulation and metabolic regularity of different in different vegetables.It can provide some references of pesticide safety application in the vegetables.The main results were as follows:The research of the difference of absorption and transfer on five new neonicotinoid insecticides in komatsu vegetables:based on indoor potted experiment,The experiment studied different degradation and residue rules of 5 different kinds of new neonicotinoid on the same vegetables komatsu.Five drug can enter into the plants through roots and transferred the shoot.Acetamiprid is the most easy to accumulate in komatsu,and thiamethoxam is the least.In addition,the metabolite of thiamethoxam is clothianidin in shoot,especially in root.The study about the absorption and metabolism of imidacloprid and its metabolites in two kinds of vegetables:through indoor potted experiment,the experiment compared the absorption,accumulation and metabolism of imidacloprid and its metabolites in garden chrysanthemum and komatsu.It was found that chrysanthemum had more concentration of drugs in root,shoot and soil.Imidacloprid and its metabolites were transferred from the soil to the root in komatsu,which was easier than chrysanthemum.The rule that Imidacloprid and its metabolites were transferred from the root to the shoot was opposite.In addition,the metabolism of imidacloprid had little difference between two vegetables,but it was easier to degrade in the komatsu than in the chrysanthemum.Effects of root exudates on bound pesticides:the experiment compared six root exudates of oxalic acid,citric acid,glycine,alanine,glucose and fructose on the effects on bound pesticides.Organic acids had the most effects and sugars had a little of effect on the activation of bound pesticides.In the experiment on the differences of five different kinds of vegetables:komatsu,chrysanthemum,high stem white,Shanghai green,dwarf yellow absorbed and activatied bound pesticides.The results was that the easiest absorption of difenoconazole and imidacloprid was komatsu and chrysanthemum.