桃苗圃适用除草剂的筛选、混配与安全性评价OA北大核心CSTPCD

[Objective]Weed control is an important step for fruit tree production.To investigate the safety of different herbicides,suitable herbicides for peach nurseries and orchards were screened in peach production,which can provide theoretical basis for the application of chemical herbicides in the peach industry.[Method]To preliminarily screen the safety of 13 herbicides,the peach seedlings combined with Lolium perenne,Cynodon dactylon,Alternanthera philoxeroides,Trifolium repens and Medicago falcata were evaluated in pot.Based on the results of the phytotoxicity index of each herbicide,10%quizalofop-p-ethyl and 60%quinclorac were mixed.According to the effective doses of 25,50,and 75 mL·hm-2 of quizalofop-p-ethyl and 150,300,450 g·hm-2 of quinclorac,a total of 9 herbicide mixtures were established.After 7,14,and 21 d of stem and leaf spraying treatment,the weed inhibition rate was investigated.After 30 d of the treatment,the plant height,stem diameter,aboveground and underground biomass,electrolyte permeability of the leaf and root tip cells,total root length,total root surface area,root volume and root tip number of peach seedlings were also measured.Based on principal component analysis,the safety of different treatments was comprehensively evaluated.[Result]After spraying on the stems and leaves of peach seedlings,11 herbicides caused phytotoxicity in peach seedlings,resulting in varying degrees of symptoms such as chlorosis,wilting,and withering.However,quizalofop-p-ethyl and quinclorac had no significant effect on the growth of peach seedlings.After spraying weeds with a single agent of quizalofop-p-ethyl for 21 d,the inhibition rate of quizalofop-p-ethyl on gramineous weeds was 100%.However,it had no effect on broad-leaved weeds.On the contrary,the inhibition rate of spraying quinclorac on gramineous weeds was 0,and the inhibition rate range of M.falcata,T.repens and A.philoxeroides was 80%to 100%.After being mixed with quizalofop-p-ethyl and quinclorac,the total weed inhibition rate under 9 compound preparations could reach over 90%after 21 d.Meanwhile,each formulation had no significant effect on the height of peach seedlings,aboveground and underground biomass,electrolyte permeability of the leaf and root tip cells.The comprehensive analysis showed that the effective dose of quizalofop-p-ethyl had a significant impact on the comprehensive evaluation D value of the mixed formulation.When the effective dose of quizalofop-p-ethyl increased to 75 mL·hm-2,the comprehensive evaluation D value of the mixed formulation exceeded 0.563,but there was no trend between the increasing D value and the increase of the effective dose of quinclorac.[Conclusion]Peach seedlings are sensitive to most herbicides,and mixing is an effective measure to improve the comprehensive weed inhibition rate of quizalofop-p-ethyl and quinclorac.After mixing an effective dose of 75 mL·hm-2 quizalofop-p-ethyl with 300 g·hm-2 quinclorac,the comprehensive evaluation D value of the formulation is the highest,which can achieve the best weed inhibition rate while ensuring the safety of peach seedlings.