Effects Of Herbicides On Weed Control And Growth Of Three Medicinal And Edible Wild Vegetables

Astragalus membranaceus,perilla and dandelion,as a kind of medicinal and edible wild vegetables,are favored by people because of their rich nutritional value and high medicinal value.With the gradual increase of planting area and scale,the difficulty of weeding is increasing.At present,artificial weeding cannot meet the demand of large-scale planting of medicinal and edible homologous wild vegetables.Weeding problem has become one of the key problems limiting the large-scale industrialization development of medicinal and edible homologous wild vegetables.Wild vegetables are seriously harmed by weeds at seedling stage,which promotes the spread and spread of diseases and pests.Mixed with weeds during harvest will increase the difficulty of processing and reduce the quality.Although the use of chemical herbicides can effectively control weeds,improper use of chemical herbicides will lead to drug damage,resulting in crop yield and quality.This study took Astragalus membranaceus,Perilla and dandelion as the test materials.By studying the effects of pre-seedling and post-seedling herbicide types,application amounts and application periods on weed control effects,safety,growth and quality of the three kinds of wild vegetables,it is expected to provide theoretical basis for the establishment of chemical control system for the field weeds of the three wild vegetables.Provide reference for production.The following results are obtained through the experiment:(1)The suitable pre-seedling herbicides for astragalus membranaceus,perilla and dandelion were selected as pendimethalin,napropamide and s-metolachlor respectively.The plant control efficiency of2 gramineous weeds,2 broad-leaved weeds and total weeds increased with the increase of the dosage.The plant control effects of astragalus membranaceus treated with 0.23L/hm~2of pendimethalin,perilla treated with 0.15kg/hm~2of napropamide and dandelion treated with 0.75L/hm~2of s-metolachlor on 2kinds of gramineous weeds,2 kinds of broad-leaf weeds and total weeds were 90%,80%and 85%,respectively.The seedling protection rate of astragalus membranaceus,perilla and dandelion reached the highest at 30d after emergence and the plant height at 90d after emergence.3 treatments at 90d after emergence,the drug damage levels of astragalus membranaceus,perilla and dandelion were 0.94,1.20and 0.86,respectively.All treatments effectively increased the yield,and the herbicide residues in the leaves did not exceed the standard.(2)The suitable post-seedling herbicide for astragalus membranaceus and perilla was screened as quizalofop-p-ethyl,and the suitable post-seedling herbicide for dandelion was haloxyfop-p.The two post-seedling herbicides had the best safety and weed control effect on astragalus membranaceus,perilla and dandelion when 50%of weeds grew to 3-4 leaf stage.The plant control efficiency of two gramineous weeds,two broad-leaved weeds and total weeds of astragalus membranaceus,perilla and dandelion increased with the increase of the dosage.Among the suitable post-seedling herbicide treatments with different dosage,the control efficiency of astragalus membranaceus under 0.6L/hm~2quizalofop-p-ethyl treatment,perilla under 0.9L/hm~2quizalofop-p-ethyl treatment and dandelion under0.75L/hm~2haloxyfop-p treatment on two kinds of gramineous weeds and the total weeds reached 90%and 85%,respectively.The seedling protection rate of astragalus membranaceus,perilla and dandelion reached the highest at 30d after emergence and the plant height at 90d after emergence of astragalus membranaceus,perilla and dandelion reached 0.93,1.29 and 1.11 at 90d after emergence of astragalus membranaceus,perilla and dandelion.Three treatments effectively increased the yield,and the herbicide residues in the leaves did not exceed the standard.(3)The contents of soluble protein in astragalus membranaceus,perilla and dandelion,total saponins in astragalus membranaceus,flavonoids in perilla and chlorogenic acid in dandelion were significantly increased by different doses of pre-emergence and post-emergence herbicides.Astragalus membranaceus treated with 0.23L/hm~2pendimethalin or 0.6L/hm~2quizalofop-p-ethyl,perilla treated with 0.15kg/hm~2napropamide or 0.9L/hm~2quizalofop-p-ethyl,and dandelion treated with 0.75L/hm~2s-metolachlor or 0.6L/hm~2haloxyfop-p,The contents of soluble protein and three specific components of astragalus membranaceus,perilla and dandelion were the highest,respectively.(4)The improvement of SOD(superoxide dismutase),POD(peroxidase)and CAT(catalase)activities was conducive to alleviating the harm caused by herbicide on astragalus membranaceus,,perilla and dandelion.The SOD,POD and CAT activities in the leaves of three kinds of wild vegetables were increased to a certain extent by the application of both pre-emergence and post-emergence herbicides,and the activities of these three enzymes were all at a high level for the treatment with good herbicidal effect and light drug damage.