替代物种与除草剂对紫茎泽兰的防效及其互作效应

Control effects of alternative species and herbicides on Ageratina adenophora and their interaction

【目的】研究替代物种与选择性除草剂,以实现对紫茎泽兰安全、高效和绿色的防控。【方法】采用植物间竞争试验法测定替代物种(高丹草、非洲狼尾草和黑麦草)和除草剂对紫茎泽兰的防效及其互作效应。【结果】高丹草、非洲狼尾草和黑麦草的竞争力依次强于紫茎泽兰。随着3种替代物种密度比例增加,紫茎泽兰的株高、分枝、根冠比、叶面积比均受到显著抑制,当替代物种与紫茎泽兰密度比为5∶1时,高丹草、非洲狼尾草和黑麦草对紫茎泽兰的替代控制效果分别为55.1%、46.9%和40.3%。除草剂氨氯吡啶酸、三氯吡氧乙酸、氯氟吡氧乙酸和二氯吡啶酸的毒力测定表明,二氯吡啶酸相对最高,LC_(90)为902.1 g·hm^(-2),但三氯吡氧乙酸对替代物种的安全性相对最好,对高丹草、非洲狼尾草和黑麦草选择性指数分别为3.75、2.79和2.67。高丹草和非洲狼尾草与紫茎泽兰种植密度比例为3∶1时,结合二氯吡啶酸和三氯吡氧乙酸,非洲狼尾草和二氯吡啶酸结合表现拮抗作用,与三氯吡氧乙酸结合表现加成作用;高丹草和二氯吡啶酸结合表现加成作用,与三氯吡氧乙酸结合表现增效作用,在同等取得90%防效的情况下,可减少三氯吡氧乙酸用量20.0%~35.0%(即210.0~370.0 g·hm^(-2))。【结论】合理的替代物种结合除草剂应用可实现互作增效,可作为紫茎泽兰综合防控的重要措施。

【Aim】To explore the ecological management of Ageratina adenophora through combinations of alternative species and herbicide applications.【Method】The control effects of competitive species(such as Sorghum bicolor×S.sudanense,Pennisetum squamulatum,and Lolium perenne)and herbicides(such as aminopyralid,triclopyr,fluroxypyr,and clopyralid)on A.adenophora and their interaction effects were determined using competition experiments.Three ratios of these competitive species and the invasive species were utilized(1∶1,3∶1,5∶1)in a complete randomized design with 4 replicates.【Result】The competitive balance index of S.bicolor×S.sudanense,P.squamulatum and L.perenne was greater than zero for most ratios,except for the 1∶1 ratio of L.perenne and A.adenophora.Plant height,branch,root shoot ratio,and leaf area ratio of A.adenophora were significantly reduced with increasing proportions of the three alternative species.The replacement control effects of S.bicolor×S.sudanense,P.squamulatum and L.perenne on A.adenophora were 55.1%,46.9%and 40.3%at the highest ratio of three alternative species∶A.adenophora(5∶1),respectively.Toxicity test showed that among the four herbicides analyzed,the clopyralid had the highest bioactivity(LC_(90)=902.1 g·hm^(-2))in A.adenophora.However,triclopyr had higher safety to three alternative species,with the selectivity index of 3.75,2.79 and 2.67 to S.bicolor×S.sudanense,P.squamulatum,and L.perenne,respectively.For a ratio of S.bicolor×S.sudanense and P.squamulatum to A.adenophora of 3∶1 plus triclopyr and clopyralid application,P.squamulatum showed an antagonistic effect with clopyralid and an additive effect with triclopyr.S.bicolor×S.sudanense had an additive effect with clopyralid and synergistic effect with triclopyr,respectively.Compared to triclopyr application alone over 90%of the control rate,the use dosage of triclopyr was reduced by 20.0%-35.0%(i.e.,210.0-370.0 g·hm^(-2))when S.bicolor×S.sudanense and triclopyr combination.【Conclusion】These results suggest that alternative species competition and herbicide combinations can achieve a more secure,sustainable,and long-term control of A.adenophora.