苦豆子总碱光分解特性和防治菜青虫及对蔬菜品质的影响

Photolysis of total alkaloids of Sophora alopecuroides and the effects on imported cabbageworm and vegetable quality

研究了苦豆子总碱(Total alkaloids ofSophora alopecuroides)在太阳光及紫外光照射下的光分解现象,发现其属于光易分解物质,其光分解半衰期不超过1 h。用4种不同浓度苦豆子总碱防治菜青虫,并与40%氧乐果比较,结果表明苦豆子总碱浓度1 g/kg防治效果最好,杀虫效果平均达80.6%。以清水为对照,采用间接萃取比色法,在喷药1、4、71、0 d后采集样品,测定其残留,4种处理的残留均未检出;进行蔬菜生理指数的测定,结果显示喷药后叶绿素的含量显著增加,亚硝酸盐和维生素C含量亦变化明显。

The photolysis of total alkaloids of Sophora alopecuroides under sunlight and ultraviolet light was studied. The results showed that the total alkaloids of S. alopecuroides decomposed easily under the lights and their half-lifes were less than one hour. The experiments of controlling imported cabbageworm with four different concentrations of total alkaloids were conducted and 40 % omethoate was used as a control. The experimental results showed that when the concentration of total alkaloids was 1 g/kg, the control efficiency was best and averagely 80.6%. The residue analysis showed that no residue of total alkaloids was found in the samples collected at 1, 4, 7 and 10 days after application. The tests for physiological indexes of samples showed that the chlorophyll content increased significantly and the contents of vitamin C and nitrite changed obviously.