Weed Community Composition And Control Measures In Oat Field Of Qinghai Province

In this paper,field experiments and indoor bioassay experiments were combined to carry out the comparative analysis of weed community composition in Qinghai oat field and its similarity with other crop fields.The chemical herbicides,their mixed combinations and biocontrol bacteria were screened for the dominant weeds in oat field,and the synergistic effect of weed control additives and biocontrol strains on the reduction of chemical herbicides was explored.The main results were as follows :1.Galium spurium L.,Elsholtzia densa Benth,Lepyrodiclis holosteoides(C.A.Mey.)Fisch.et Mey,Chenopodium album L.,Daucus carota L.,and Bromus tectorum L.are the dominant weeds in oat at present.The comparative analysis of weed community similarity in different crop habitats showed that the species richness of weed community in oat field was higher than that in highland barley field.The weed communities of oat and cabbage rape,highland barley,wheat and cabbage rape were highly similar.2.Two test combinations were selected to control the dominant weeds such as Elsholtzia densa Benth,Galium spurium L.,Lepyrodiclis holosteoides(C.A.Mey.)Fisch.et Mey and Chenopodium album L.in oat field,and were safe to oats.Strains 12 – 6,16 – 8,and 10 – 7 were screened from 12 biocontrol strains,and the fresh weight inhibitory effects of them on Galium spurium L.,Elsholtzia densa Benth,and Chenopodium album L.were good,indicating that they had the potential for further development.3.NF-100,film-forming additive and Dixiao were selected from the six additives to improve the control effect of 20 % bensulfuron-methyl·chlorofluoropyroxyacetic acid WP on broadleaf weeds in oat field.Under the same control effect,the by about 30 % under the same control effect.The mixture of biocontrol strain 12-6 and 20 % chlorofluoropyroxyacetic acid EC could effectively improve the control effect of herbicides on C.sojae and reduce the dosage of the herbicide by20 % – 30 %.