Studies Of Weed Community Characteristics And Herbicide Screening In A.sinensis Field Based On Various Crop Residues

As an important authentic medicinal material in Gansu,Angelica sinensis plays an important role in the local economic development.With the development of the industrialized production,the mechanized production will become the future trend in the plant production development.However,due to the special environment in the local production area,the weeds in the plant fields have become more serious,resulting in yield reduction.Artificial weeding increases the cost of cultivation,hindering the industrialized development of the Angelica.The Angelica were cultivated in different local crop residues and the weeds were measured in timely in this study in order to explore the weed community and the differences in Angelica fields under different crop residues,and finally to screen out the highly efficient herbicides without harmness so that providing scientific and technical basis for the standardized cultivation.The results are summarized as follows:1.The study on the weed communities in the Angelica nursery fields under different residue showed that Gentiana and bean residue were beneficial to the Angelica seedlings.Medicinal plant residue as Gentiana and crop residue as bean both have the same advantage weed communities,which were Malva sinensis,Senecio vulgaris,Hypecoum leptocarpum,Fagopyrum gilesii,Chenopodium glaucum and Sonchus oleraceus.It is showed that the weed community in Angelica nursery fields in the same agro-ecological area is relatively stable,which did not varied with the residues but change their relative advantage abundance.2.The study on the weed communities in the Angelica fields under different residues showed that Gentiana,Bean and Cole residue were beneficial to the Angelica cultivation.The weed advantage communities in different residue is the same,but the relative abundance was different from the residues.M.sinensis,S.vulgaris,Cirsium setosum,S.oleraceus and Stellaria media were the common advantage weeds in each residue.Different composition of dvantage weed community in cultivated field and nursery field.S.vulgaris and S.oleraceus were vicious weeds in Angelica nursery and cultivation field.C.setosum and S.media are vicious weeds in Angelica cultivation field.H.leptocarpum,C.album and F.gilesii were vicious weeds in Angelica nursery field.Due to the fact that Angelica plants had various tolerance to weeds,the adult medical plants had more tolerance to weeds compared with the seedlings.3.Eight kinds of pre-emergence and post-emergence herbicides were selected bycomparing the injury extent to the Angelica seedlings in Lab.The result showed that Oxyfluorfen,Clopyralid,Bentazone and Fluroxypyr had serious damage to the Angelica seedlings.However,the hazard is not obvious when using Pendimethalin,Trifluralin,Sethoxydim and Haloxyfop-R-methy.4.Based on Lab screening of Angelica herbicides,the effect of herbicides on the weed communities were studied in the medical plant cultivated fields in Shichuan township,Zhang county.The result showed that they were 6 advantage weeds,such as V.verecunda,S.media,T.arvense,C.setosum,G.aparine and F.gilesii under no weeding conditions.The herbicides had influence on the weed control effect,resulting in difference in quality and yield of Angelica,finding Trifluralin and Pendimethalin had residues both in the medical materies and soils,however,Quizalofop-p-ethyl(15%)and Sethoxydim treatmen exhibited the best control effect for the weeds and high security for the Angelica.