Goosegrass is one of the worst agricultural weeds on a worldwide basis. Understanding of its interference impact in crop ifeld wil provide useful information for weed control programs. Field experiments were conducted...Goosegrass is one of the worst agricultural weeds on a worldwide basis. Understanding of its interference impact in crop ifeld wil provide useful information for weed control programs. Field experiments were conducted during 2010–2012 to determine the inlfuence of goosegrass density on cotton growth at the weed densities of 0, 0.125, 0.25, 0.5, 1, 2, and 4 plants m–1 of row. Seed cotton yield tended to decrease with the increase in weed density, and goosegrass at a density of 4 plants m–1 of row signiifcantly reduced cotton yields by 20 to 27%. A density of 11.6–19.2 goosegrass plant m–1 of row would result in a 50%cotton yield loss from the maximum yield according to the hyperbolic decay regression model. Bol production was not affected in the early growing season. But bol numbers per plant were reduced about 25%at the den-sity of 4 plants m–1 of row in the late growing season. Both cotton bol weight and seed numbers per bol were signiifcantly reduced (8%) at 4 goosegrass plants m–1 of row. Cotton plant height, stem diameter and sympodial branch number were not affected as much as cotton yields by goosegrass competition. Seed index, lint percentage and lint ifber properties were unaffected by weed competition. Intraspeciifc competition resulted in density-dependent effects on weed biomass per plant, 142–387 g dry weight by harvest. Goosegrass biomass m–2 tended to increase with increasing weed density as indicated by a quadratic response. The adverse impact of goosegrass on cotton yield identiifed in this study has indicated the need of effective goosegrass management.展开更多
Field studies were conducted in 2012 and 2013 to evaluate weed and insect control efficacy with glyphosate at 1 230 g ai（active ingredient） ha^（-1） and the insecticides acephate（728 g ai ha^（-1））,carbosulfan（...Field studies were conducted in 2012 and 2013 to evaluate weed and insect control efficacy with glyphosate at 1 230 g ai（active ingredient） ha^（-1） and the insecticides acephate（728 g ai ha^（-1））,carbosulfan（135 g ai ha^（-1））,endosulfan（683 g ai ha^（-1））,imidacloprid（32 g ai ha^（-1））,or lambda-cyhalothrin（23 g ai ha^（-1））,as well as glyphosate tank-mixed with these insecticides.Four of the most common weeds in cotton,common purslane,false daisy,goosegrass,and lambsquarters,were manually sown in the cotton field and treated with glyphosate alone or in combination with insecticides.Glyphosate efficacy,based on visual estimates of control and weed fresh weight at 21 d after treatment（DAT）,was unaffected by the addition of insecticides.Four weeds were controlled by 93-97%and 86-100%（visual rating） and reduced weed fresh biomass by98-99%and 96-100%with glyphosate alone and its combination with insecticides,respectively.Addition of glyphosate to acephate improved cotton aphid control compared with acephate alone.However,addition of glyphosate to carbosulfan,endosulfan,imidacloprid,or lambda-cyhalothrin did not affect the aphid control when compared with the insecticide alone treatments.These results indicate that cotton producers could potentially integrate weed and insect management strategies by choosing suitable insecticide mixing partners with glyphosate,thereby reducing the application costs without sacrificing the efficacy of the glyphosate or the insecticides.展开更多
基金funded by grants from the National Key Technology R&D Program of China (2012BAD19B05)the Fundamental Research Funds for Central Public Welfare Research Institutes, China (SJB1005)
文摘Goosegrass is one of the worst agricultural weeds on a worldwide basis. Understanding of its interference impact in crop ifeld wil provide useful information for weed control programs. Field experiments were conducted during 2010–2012 to determine the inlfuence of goosegrass density on cotton growth at the weed densities of 0, 0.125, 0.25, 0.5, 1, 2, and 4 plants m–1 of row. Seed cotton yield tended to decrease with the increase in weed density, and goosegrass at a density of 4 plants m–1 of row signiifcantly reduced cotton yields by 20 to 27%. A density of 11.6–19.2 goosegrass plant m–1 of row would result in a 50%cotton yield loss from the maximum yield according to the hyperbolic decay regression model. Bol production was not affected in the early growing season. But bol numbers per plant were reduced about 25%at the den-sity of 4 plants m–1 of row in the late growing season. Both cotton bol weight and seed numbers per bol were signiifcantly reduced (8%) at 4 goosegrass plants m–1 of row. Cotton plant height, stem diameter and sympodial branch number were not affected as much as cotton yields by goosegrass competition. Seed index, lint percentage and lint ifber properties were unaffected by weed competition. Intraspeciifc competition resulted in density-dependent effects on weed biomass per plant, 142–387 g dry weight by harvest. Goosegrass biomass m–2 tended to increase with increasing weed density as indicated by a quadratic response. The adverse impact of goosegrass on cotton yield identiifed in this study has indicated the need of effective goosegrass management.
基金provided by the Fundamental Research Funds for Central Public Welfare Research Institutes,China(SJB1202)
文摘Field studies were conducted in 2012 and 2013 to evaluate weed and insect control efficacy with glyphosate at 1 230 g ai（active ingredient） ha^（-1） and the insecticides acephate（728 g ai ha^（-1））,carbosulfan（135 g ai ha^（-1））,endosulfan（683 g ai ha^（-1））,imidacloprid（32 g ai ha^（-1））,or lambda-cyhalothrin（23 g ai ha^（-1））,as well as glyphosate tank-mixed with these insecticides.Four of the most common weeds in cotton,common purslane,false daisy,goosegrass,and lambsquarters,were manually sown in the cotton field and treated with glyphosate alone or in combination with insecticides.Glyphosate efficacy,based on visual estimates of control and weed fresh weight at 21 d after treatment（DAT）,was unaffected by the addition of insecticides.Four weeds were controlled by 93-97%and 86-100%（visual rating） and reduced weed fresh biomass by98-99%and 96-100%with glyphosate alone and its combination with insecticides,respectively.Addition of glyphosate to acephate improved cotton aphid control compared with acephate alone.However,addition of glyphosate to carbosulfan,endosulfan,imidacloprid,or lambda-cyhalothrin did not affect the aphid control when compared with the insecticide alone treatments.These results indicate that cotton producers could potentially integrate weed and insect management strategies by choosing suitable insecticide mixing partners with glyphosate,thereby reducing the application costs without sacrificing the efficacy of the glyphosate or the insecticides.
