Study On Safety Of Eight Herbicides To Scutellaria Baicalensis Georg

In this project the effects of four premergence herbicides roundup、shangge747、S-metolachlor and acetochlor on seeds germination and seedling growth of Scutellariabaicalensis Georg were studied by approach of laboratory, the effects of four postemergenceherbicides nicosulfuron·atrazine、basagran、Haloxyfop-R-methyl and quizalofop-p-ethyl onseedling growth of Scutellaria baicalensis Georg was investigated in pot experiment。The lawof weeds occurrence were summed up in Scutellaria baicalensis Georg fields by fieldexperiments, and to further determine the impact on the growth of Scutellaria baicalensisGeorg and the herbicidal effect of premergence herbicides S-metolachlor、acetochlor andpostemergence herbicides Haloxyfop-R-methyl、nicosulfuron·atrazine that were preliminaryselectioned in laboratory experiments.at the same time, the phytotoxicity symptoms ofScutellaria baicalensis Georg and weeds were recorded in our experiments.The results arebrought forward as following:1、Four premergence herbicides had no effect on seed germination but seedling growthwas inhibited in the laboratory experiment。2、Four postemergence herbicides were safe and harmless to Scutellaria baicalensisGeorg at the laboratoty condition except basagran。3、Field experiment showed that nicosulfuron·atrazine caused injury at the field condition,so it can’t be used as sprays to control weeds in Scutellaria baicalensis Georg.Acetochlor、S-metolachlor and Haloxyfop-R-methyl was safe to Scutellaria baicalensis Georg,they can beused as sprays to control weeds in Scutellaria baicalensis Georg.4、In our experimental field, the dominant weed species in Scutellaria baicalensis Georgwere: Datura stramonium L、Setaria viridis （L）Beauv、Convolvulus arvensis L and soon.The weeds occurred around April16,the weed’s occurrence peak appears around May21，the postemergence herbicidal should be finished by the middle of May.5、Acetochlor had best effect on controlling Veronica didyma Tenore,while the effect was stable on Setaria viridis （L）Beauv、Convolvulus arvensis L and Veronica didymaTenore. S-metolachlor had best effect on controlling Convolvulus arvensis L,while it hadworst effect on controlling Veronica didyma Tenore. Haloxyfop-R-methyl was effective incontrolling grassy weed Setaria viridis （L）Beauv.6、Considering the crop safety and herbicidal effect, acetochlor and S-metolachlor can beused as pre-emergent sprays to control most of grassy weeds and broadleaf weeds,Haloxyfop-R-methyl can be used as post-emergence spray to control grassy weeds.7、The postemergence broadleaf weeds herbicides that can be used in Scutellariabaicalensis Georg have not be determined yet, can not be free to use, so as to avoid theoccurrence of phytotoxicity.8、Phytotoxicity symptoms of Scutellaria baicalensis Georg that caused by someherbicides:In the laboratory experiment,the phytotoxicity symptoms that caused by “747” androundup:rust-colored phytotoxicity spots appear on the leaves of Scutellaria baicalensisGeorg.In pot experiment, the phytotoxicity symptoms that caused by basagran: at fist,the upperleaves of Scutellaria baicalensis Georg seeddlings become drooping and wilting, the leaf tipsbecome soft that like be scalded by boiling water, and then the leaves wrinkle and curl, finallyphytotoxicity appears on the growth points.In field experiment, the phytotoxicity symptoms that caused by nicosulfuron-·atrazine：the phytotoxicity spots appear on the leaf tips and edges fist, which are light green,and then the phytotoxicity area expand, the leaves curl.