Field Weed Investigation And Effect Of Agents Stress On Active Components Of Astragalus Membranaceus

Astragalus is one of the major Chinese medicinal materials.With the rapid increase of standardized planting area,diseases,insect,pest and weeds have become one of the important factors restricting the high quality green production of Astragalus membranaceus.The application of chemical pesticides will not only lead to excessive pesticide residues,but also cause problems in the safety of chinese medicine.This experiment was conducted to investigate the occurrence of weeds in the fields of Astragalus membranaceus in Liupanshan of Ningxia,and chemical control of major diseases,insect pests,and the effects of chemical pesticides on their growth and active ingredients.The results as follows:(1)The test of investigation of weeds in the field of Astragalus membranaceus showed:The dominant species of weeds in the field were herba cirsll,field bindweed,sonchus brachyotus and plumed thistle root and chenopodium glaucum 1.Calystegin hederacea,chenopodium glaucum 1,plumed thistle root and ixeris chinensis has more serious harm for the growth of the Astragalus membranaceus.(2)The test of soil chemical properties showed:In the harvest period of Astragalus membranaceus,alkali-hydrolyzed nitrogen,organic matter,calcium and magnesium was decreased in the soil,organic matter decreased most,calcium second.(3)The test of effects of herbicides on the growth of Astragalus seedlings showed:1/2 dimethylpentalin+1/2 oxyfluorfen agent treatment had little effect on seedling growth and high safety.(4)Pest control experiments show that:After treatment of different agents,disease leaf number of powdery mildew in general trend decreased,the incidence rate,the disease index decreased,the control effect reached 100%after treatment with low and high concentrations of symclosene;The control effect of aphids reached more than 95%.(5)The test of effect of agent on growth and active ingredients of Astragalus membranaceus showed:In agents for control aphids,the treatment of high-efficiency cypermethrin with low concentration has little effect on the growth of Astragalus membranaceus and high safety,the content of astragaloside IV and ononin was highest after treatment with low concentration of imidacloprid,astragaloside IV increased by 0.067 mg·g-1,ononin decreased by 0.021 mg·g-1;the content of calycosin-7-glucoside was highest after treatment with low concentration of matrine,decreased by 0.352 mg·g-1.In agents for control powdery mildew,the treatment of thiophonate-methyl with low concentration has little effect on the growth of Astragalus membranaceus and high safety,the highest content of calycosin-7-glucoside and ononin,increased by 0.043 mg·g-1 and 0.079 mg·g-1,the content of astragaloside IV was the highest after treatment with low concentration of nitrobenzene ester,increased by 0.140 mg·g-1.In agents for control downy mildew,the treatment of propamocarb with high concentration has little effect on the growth of Astragalus membranaceus and high safety,the content of astragaloside IV was highest after treatment with the medium concentration of propamocarb,increased by 0.310 mg·g-1;the content of calycosin-7-glucoside was highest after treatment with the high concentration of chlorothalonil,decreased by 0.260 mg·g-1;the content of ononin was highest after treatment with the medium concentration of bordeaux mixture,decreased by 0.040 mg·g-1.