【摘要】 针对高寒草地毒害草瑞香狼毒Stellera chamaejasme L.的防控需求及农药减量增效目标，本研究结合校正株防效和地上生物量鲜重防效(下文简称鲜重防效)双效评价体系，动态监测施药后15～45 d的剂量效应与助剂协同作用，解析了三氯吡氧乙酸、2,4-滴异辛酯和苯磺隆的防效机制及时效动态规律。结果表明：高剂量处理(三氯吡氧乙酸450 g/hm~2、2,4-滴异辛酯1 650 mL/hm~2和苯磺隆360 g/hm~2)防效始终显著优于各自中(三氯吡氧乙酸225 g/hm~2、2,4-滴异辛酯825 mL/hm~2和苯磺隆180 g/hm~2)、低剂量(三氯吡氧乙酸112.5 g/hm~2、2,4-滴异辛酯412.5 mL/hm~2和苯磺隆90 g/hm~2)(P<0.05),施药后45 d,三氯吡氧乙酸、2,4-滴异辛酯和苯磺隆的株防效分别为93.13%、96.27%和82.12%,但也造成了珠芽蓼Polygonum viviparum、高原毛茛Ranunculus tanguticus等草地植物幼苗1.35%～7.41%的死亡率，表现出一定程度的药害。添加0.1%有机硅助剂可使低剂量三氯吡氧乙酸实现90.64%株防效，与中剂量处理无显著差异(P>0.05),同时减少50%药剂用量。由于三氯吡氧乙酸存在维管束运输滞后效应，其起效相对较缓，高剂量处理45 d株防效和鲜重防效分别为93.13%和85.72%,高效抑制瑞香狼毒的生长，相比之下，除草剂作用动力学显示，2,4-滴异辛酯表现出更佳的速效性。苯磺隆各处理45 d株防效介于54.98%～82.12%,与其他2种除草剂相比，防效较差。基于天然草地狼毒危害等级差异，提出分级防控策略：重度危害区(密度>15株/m~2)采用1 650 mL/hm~2的2,4-滴异辛酯快速压制种群数量；中度危害区(5～15株/m~2)应用112.5 g/hm~2三氯吡氧乙酸+有机硅助剂方案，在保证较高防效的同时降低除草剂用量，并结合补播牧草提高草地生产力。更多还原

【Abstract】 Addressing the control demand of the poisonous weed Stellera chamaejasme L. in alpine grasslands and aiming at pesticide reduction and efficiency improvement, this study employed a dual-evaluation system of corrected plant control efficacy and above-ground fresh weight control efficacy(hereinafter referred to as fresh weight efficacy). Over a 15-45 day period after application, we dynamically monitored dose-response relationships and the synergistic effects of adjuvants, systematically elucidating the mechanisms of action and temporal dynamics of triclopyr, 2,4-D ethylhexyl, and tribenuron-methyl. The results showed that high-dose treatments(triclopyr 450 g/hm~2, 2,4-D ethylhexyl 1 650 mL/hm~2, and tribenuron-methyl 360 g/hm~2) consistently outperformed the corresponding medium(triclopyr 225 g/hm~2, 2,4-D ethylhexyl 825 mL/hm~2, tribenuron-methyl 180 g/hm~2) and low doses(triclopyr 112.5 g/hm~2, 2,4-D ethylhexyl 412.5 mL/hm~2, tribenuron-methyl 90 g/hm~2)(P<0.05). Plant control efficacies were 93.13% for triclopyr, 96.27% for 2,4-D ethylhexyl, and 82.12% for tribenuron-methyl, respectively. However, non-target meadow species such as Polygonum viviparum and Ranunculus tanguticus experienced seedling mortality rates of 1.35%-7.41%, indicating a certain degree of phytotoxicity. Adding 0.1% organosilicon adjuvant enabled the low dose of triclopyr to achieve a 90.64% plant control efficacy, which was not significantly different from that of the medium dose(P>0.05), while reducing the herbicide amount by 50%. Kinetic analysis revealed that 2,4-D ethylhexyl reached its efficacy inflection point at 30 days(plant control efficacy>90%). In contrast, triclopyr exhibited a delayed vascular transport effect; at the high dose, its plant and fresh weight efficacies at 45 days were 93.13% and 85.72%, respectively, strongly suppressing S.chamaejasme growth. Plant control efficacy of tribenuron-methyl at 45 days ranged from 54.98% to 82.12%, showing poorer efficacy than the other two herbicides. Based on the varying damage levels of S.chamaejasme in natural grasslands, a graded control strategy was proposed. For severe damage areas(density>15 plants/m~2), 2,4-D ethylhexyl at 1 650 mL/hm~2 is recommended to rapidly suppress the population. For moderate damage areas(5-15 plants/m~2), the combined application of 112.5 g/hm~2 triclopyr and organosilicon adjuvant is suggested, which ensures high control efficacy and reduces herbicide dosage. Meanwhile, grassland productivity can be improved by supplementary forage sowing.更多还原