Kouame Koffi Badou-Jeremie, Thrash Benjamin C, Bateman Nick R, Lorenz Gus M, Butts Thomas R
Department of Agronomy, Agricultural Research Center, Kansas State University, 1232 240th Ave, Hays, KS, 67601, USA.
Department of Entomology and Plant Pathology, University of Arkansas, Lonoke, USA.
Sci Rep. 2025 Aug 4;15(1):28448. doi: 10.1038/s41598-025-14066-0.
Auxin mimic herbicide off-target movement is a major environmental concern; it can affect crop yield, endangered species, and pollinator foraging sources. For the first time, the effects of sublethal rates of four auxin mimic herbicides (2,4-D, dicamba, florpyrauxifen-benzyl, and quinclorac) were evaluated to improves our understanding of how these herbicides negatively impact a pollinator nutritional source of pollinators. Dicamba and florpyrauxifen-benzyl applied at 1/100x of the labeled rate (5.60 g ae ha dicamba and 0.30 g ha florpyrauxifen-benzyl) reduced the total number of soybean reproductive organs (flowers and pods) by 31% and 27%, respectively, compared to the nontreated control (n = 373). Exposure to the same rates reduced pollen grains per anther by 25% and 18%, respectively, compared to the nontreated control (n = 338). The maximum reproductive per plant biomass accumulated was reduced by 30% from sublethal rates of dicamba and florpyrauxifen-benzyl applications at 1/100x compared to the nontreated control (23 g plant-1). An application of dicamba and florpyrauxifen-benzyl at 1/100x resulted in a 24% and 11% reduction in grain yield, respectively, compared to the nontreated control (3063 kg ha-1). While soybean reproductive organs, pollen grains, and yield were reduced from dicamba and florpyrauxifen-benzyl, 2,4-D and quinclorac had no impact on soybean physiological responses in this study. These results reinforce the idea that exposure to auxin mimic herbicides could reduce the quantity of pollen which could negatively affect pollinators' foraging sources. Albeit, this relationship is highly dependent on the specific herbicide active ingredient and rate. This trend could have major implications for commercial bee keepers regarding the health of their bees near soybean fields that had drift damage. Proactive mitigation strategies are required when using auxin mimic herbicides to prevent off-target movement and subsequent negative consequences for pollinator foraging sources.
生长素类似物除草剂的非靶标移动是一个重大的环境问题；它会影响作物产量、濒危物种和传粉者的觅食来源。首次评估了四种生长素类似物除草剂（2,4-滴、麦草畏、氟吡草酮苄酯和二氯喹啉酸）亚致死剂量的影响，以增进我们对这些除草剂如何对传粉者的营养来源产生负面影响的理解。与未处理对照相比（n = 373），以标签剂量的1/100（5.60克酸等效物/公顷麦草畏和0.30克/公顷氟吡草酮苄酯）施用麦草畏和氟吡草酮苄酯，分别使大豆生殖器官（花和荚）的总数减少了31%和27%。与未处理对照相比（n = 338），暴露于相同剂量下，每个花药的花粉粒数量分别减少了25%和18%。与未处理对照（23克/株）相比，麦草畏和氟吡草酮苄酯以1/100x的亚致死剂量施用使每株植物积累的最大生殖生物量减少了30%。与未处理对照（3063千克/公顷）相比，以1/100x施用麦草畏和氟吡草酮苄酯分别使谷物产量降低了24%和11%。虽然麦草畏和氟吡草酮苄酯使大豆生殖器官、花粉粒和产量减少，但在本研究中，2,4-滴和二氯喹啉酸对大豆生理反应没有影响。这些结果强化了这样一种观点，即暴露于生长素类似物除草剂可能会减少花粉数量，这可能会对传粉者的觅食来源产生负面影响。尽管如此，这种关系高度依赖于特定的除草剂活性成分和剂量。这种趋势可能会对商业养蜂人在其靠近遭受漂移损害的大豆田的蜜蜂健康方面产生重大影响。在使用生长素类似物除草剂时，需要采取积极的缓解策略，以防止非靶标移动以及随后对传粉者觅食来源产生的负面后果。
