三种除草剂对五爪金龙的防除作用及2,4-D丁酯对环境的影响

用3种除草剂(2,4-D丁酯、麦草畏和塔隆)对五爪金龙(Ipomoea cairica L.Sweet)进行化学防除试验。结果表明:1.00 mL L-1的2,4-D丁酯可以彻底杀灭五爪金龙。喷施1.00 mL L-12,4-D丁酯20 d后,五爪金龙茎叶枯死率接近100%;60 d后五爪金龙的总生物量显著低于其它处理及对照;90 d后未出现生长恢复,最终盖度防效为99.8%。而喷施1.00 mL L-1的麦草畏40 d后,五爪金龙的茎叶枯死率为99.0%,但仍有少量存活的根,90 d后再次萌生率为10.0%;喷施1.00 mL L-1塔隆40 d后,五爪金龙的茎叶枯死率为100%,90 d后再次萌生率为100%。土壤残留分析表明:在有机质含量较高(10.14±1.01)g kg-1]的土壤中2,4-D丁酯降解速率较快,半衰期为14 d,施药后80 d的土壤中已检测不到2,4-D丁酯。此外,在野外喷洒1.0 mL L-1的2,4-D丁酯对其它植物是安全的,施药1年后,样地内的植物均能恢复生长。因此,实践中可用1.00 mL L-1的2,4-D丁酯来防除五爪金龙。

Chemical Control of Ipomoea cairica with Three Herbicides and Effect of 2,4-D Butylate on the Environment

Ipomoea cairica is a notorious weed which has serious harm to the environment in South China. The effects of three chemical herbicides, such as 2,4-D butylate, dicamba and fluroxypyr, on control of I. cairica in the field were studied. The results showed that 2,4-D butylate (1.00 mL L^-1) could eradicate this weed. The death rate of I. cairica stems and leaves was close to 100% after spraying 2,4-D butylate (1.00 mL L^-1) in 20 days. The total biomass also decreased significantly in 60 days (P<0.05), and the growth did not recovery after 90 days. The final control effect of 2,4-D butylate (1.00 mL L^-1) on Ipomoea cairica was 99.8%. After spraying dicamba (1.00 mL L^-1) and fluroxypyr (1.00 mL L^-1) in 40 days, the death rate of I. cairica stems and leaves were 99.0% and 100%, respectively, and the regeneration rate of I. cairica was 10% and 100% after 90 days. A few roots were survival sprayed dicamba (1.00 mL L^-1) after 40 days. The herbicide residue analysis showed that 2,4-D butylate could degrade quickly with half-life for 14 days, and it could not be detected in the soil after 80 days. Furthermore, 2,4-D butylate (1.00 mL L^-1) was relatively safe to other plants, which could regenerate after spraying 2,4-D butylate in 1 year. Therefore, it suggested that the Ipomoea cairica growth could be good control treated with 1.00 mL L^-1 2,4-D butylate.