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

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

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。

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 L cairica in the field were studied. The results showed that 2,4-D butylate （1.00 mL Lx） could eradicate this weed. The death rate ofL cairica stems and leaves was close to 100% after spraying 2,4-D butylate （1.00 mLLl） 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 Ll） in 40 days, the death rate ofL cairica stems and leaves were 99.0% and 100%, respectively, and the regeneration rate of/. cairica was 10% and 100% after 90 days. A few roots were survival sprayed dicamba （1.00 mL Ll） 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 L1） 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.