Field and greenhouse studies were conducted to investigate the influence of sequence and timing of synthetic auxins and glufosinate on large Palmer amaranth (Amaranthus palmeri) control. Field studies were performed in Henry County, AL where treatments were applied to Palmer amaranth with average heights of 37 and 59 cm in 2018 and 2019, respectively. Sequential applications of 2,4-D/dicamba + glyphosate followed by (fb) glufosinate at labeled rates 3 or 7 days after initial treatment (DAIT) were used in addition to the reverse sequence with a 7-day interval. Time intervals of 3 or 7 days between applications did not influence Palmer amaranth control. Palmer amaranth was controlled 100% by dicamba + glyphosate fb glufosinate and 2,4-D + glufosinate fb glufosinate 7 DAIT in 2018. However, herbicide performance was reduced due to delayed application and taller plants in 2019 with up to 23% less visual injury. To further investigate Palmer amaranth response to dicamba and glufosinate applied sequentially, a greenhouse study was conducted in 2019 where physiological measurements were recorded over a 35-day period. Treatments were applied to Palmer amaranth averaging 38 cm tall and included dicamba + glyphosate fb glufosinate 7 DAIT, the reverse sequence, and a single application of dicamba + glufosinate + glyphosate. Glufosinate severely inhibited mid-day photosynthesis compared to dicamba with up to 90% reductions in CO₂ assimilation 1 DAIT. In general, Palmer amaranth respiration and stomatal conductance were not affected by herbicides in this study. Applications of dicamba + glyphosate fb glufosinate 7 DAIT was the only treatment hindered Palmer amaranth regrowth with 52% reduction in leaf biomass compared to nontreated control. These data suggest Palmer amaranth infested fields are more likely to be rescued with sequential applications of synthetic auxins and glufosinate, but consistent control of large Palmer is not probable.

中文翻译：

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合成生长素和草铵膦在逃脱帕尔默Control菜防治中的顺序应用

进行了田间和温室研究，以研究合成植物生长素和草铵膦的顺序和时间对大Palm菜（Amaranthus palmeri）的影响。） 控制。在阿拉巴马州亨利县进行了实地研究，分别在2018年和2019年对帕玛a菜进行了处理，平均高度分别为37和59厘米。除以7天为间隔的反向序列外，还应在初始治疗（DAIT）后3或7天以标记的速率依次施用2,4-D /麦草畏+草甘膦（fb）草铵膦（fb）。两次施用之间3或7天的时间间隔不影响Palmer mar菜的控制。麦草畏在2018年受到麦草畏和草甘膦fb草铵膦和2,4-D +草铵膦fb草铵膦7 DAIT的控制。但由于除草剂施用延迟和2019年植株较高，除草剂性能下降，视力伤害降低了23％ 。为了进一步研究相继应用麦草畏对麦草畏和草铵膦的反应，2019年进行了温室研究，在35天的时间内记录了生理测量值。对帕玛a菜的平均高度为38 cm，包括麦草畏+草甘膦fb草铵膦7 DAIT的处理，相反的顺序以及麦草畏+草铵膦+草甘膦的单次施用。与麦草畏相比，草铵膦严重抑制了午间的光合作用，CO降低多达90％₂同化1 DAIT。通常，在这项研究中，Palmer mar菜的呼吸作用和气孔导度不受除草剂的影响。麦草畏+草甘膦fb草铵膦7 DAIT的施用是唯一阻止帕默a菜再生的方法，与未处理的对照相比，叶生物量减少了52％。这些数据表明，先后顺序施用合成植物生长素和草铵膦可以挽救Palmer mar菜出没的田地，但不可能对大Palmer进行一致的控制。