嘧菌酯在大豆中的沉积、降解规律及最低有效防控剂量研究

Study on the deposition,degradation and minimum effective dose of azoxystrobin in soybean

嘧菌酯是防治大豆锈病的重要杀菌剂,明确嘧菌酯在大豆上的残留规律是一项亟待开展的课题。本研究采用超高效液相色谱-串联质谱(UPLC-MS/MS)技术,建立了大豆种植体系中茎、叶、籽粒及土壤中嘧菌酯的残留分析方法,定量限达0.005 mg/kg。在田间试验点基础上,明确了安徽、山东和吉林3个试验点嘧菌酯在大豆上的沉积与降解规律,发现250 g/L嘧菌酯悬浮剂在施用后主要沉积在大豆叶片中,沉积量由北向南呈逐渐降低趋势,嘧菌酯在上部茎叶中降解速率较快,地区间无明显差异;比较了不同剂量嘧菌酯与大豆锈病防效之间的关系,同时给出了残留量,得到了嘧菌酯的最低有效防控剂量为225 g/hm^(2)。本研究成果对指导嘧菌酯在大豆生产中的科学使用以及对大豆上农药减量实践具有重要意义。

Azoxystrobin is an important fungicide to control soybean rust.It is an urgent task to clarify the residue characteristic of azoxystrobin in soybean.In this study,ultra performance liquid chromatography tandem mass spectrometry was used to establish a method for the determination of azoxystrobin residues in stems,leaves,pods and soil in soybean planting system.The limit of quantification(LOQ)was 0.005 mg/kg.The results of field experiments in Anhui,Shandong,and Jilin showed that azoxystrobin 250 g/L SC was mainly deposited in soybean leaves after application and the deposition concentration decreased gradually from north to south.The degradation rates were faster in the upper stems and leaves,and there was no significant difference between regions.The relationship between the control effect of azoxystrobin on soybean rust was compared under different doses,and the residues were provided.The minimum effective dose of azoxystrobin was 225 g a.i./hm^(2).The research results of this paper are of great significance to guide the scientific application of azoxystrobin in soybean production and the practice of pesticide reduction on soybean.