Investigation On Weed In Spring Sowing Foxtail Millet Field And Chemical Control Technique In Jinzhong City

Jinzhong city is one of the important grain-producing areas in Shanxi Province,foxtail millet,as a typical representative of minor grain crops plays an important role in organic dry farming.However,the problem of grass damage has always been an important factor restricting the development of foxtail millet industrialization.Manual weeding is time-consuming and inefficient,which is not suitable for the current situation of labor shortage in rural areas.While the chemical weeding technology in millet fields is still not perfect.Except that a few herbicides can be applied in foxtail millet fields,there are few safe herbicides in conventional foxtail millet fields.Therefore,it is necessary to define the weed community structure in valley to control weeds effectively.This experiment was conducted in the spring sowing period of 2019,and different points were selected from four spring sowing foxtail millet field planting areas in Jinzhong city of Shanxi Province.In this study,the inverted "w" nine-spot sampling method was used to investigate the species and community composition of weeds in foxtail millet fields,and the effects of five herbicides on the control of weeds in foxtail millet fields were studied,so as to provide theoretical basis and practical guidance for the effective control of weeds in foxtail millet production.The results of the study are as following:1.There were 31 species,30 genera and 14 families of weeds in spring sowing millet field in Jinzhong city.The species of weeds in Gramineae,Compositae and Chenopodiaceae were the most,with 7 species,6species and 4 species respectively,accounting for 22.58%,19.35% and 12.90% of all weed species,respectively.Broad-leaved weeds were more common,and the weed life type was mainly annual.Echinochloa crusgalli,Amaranthus retroflexus,Chenopodium album and Setaria viridis were the dominant weeds in Jinzhong city,which will seriously affect the production of foxtail millet.2.The dominant weeds in different areas were different,and the dominant weeds of Taigu County were Amaranthus retroflexus and Chenopodium album;The dominant weeds in Yuci district were Amaranthus retroflexus,Chenopodium album,Kochia scoparia and Echinochloa crusgalli;The dominant weeds in Zuoquan county were Chenopodium album,Kochia scoparia and Echinochloa crusgalli;The dominant weeds in Shouyang county were Cirsium setosum and Calystegia hederacea.Zuoquan county had the highest species richness,with 21 species of weeds,while Shitie town had the lowest species richness,with 10 species of weeds.The distribution of weeds in Shouyang county was relatively uniform,while the distribution of weeds in Zuoquan county was uneven,and the dominant population was more prominent.3.Under the recommended dosage,five kinds of herbicides treated by stem and leaf had different effects on the control of weeds in foxtail millet fields.Tribenuron-methyl and Starane had better control effect on broad-leaved weeds;Sethoxydim had a good effect on the control of gramineous weeds;Mesotrione could control both broad-leaved weeds and gramineous weeds in foxtail millet fields,but its control effect on broad-leaved weeds was higher than that of gramineous weeds;Bensulfuron-methyl had a poor control effect on weeds in foxtail millet fields,and its control effect on gramineous weeds and broad-leaved weeds was significantly lower than that of other 4 herbicides.