Interaction of 2,4-D or Dicamba with Glufosinate for Control of Glyphosate-Resistant Giant Ragweed (Ambrosia trifida L.) in Glufosinate-Resistant Maize (Zea mays L.)

Abstract

Glyphosate-resistant (GR) giant ragweed is a problematic broadleaf weed in crops including maize and soybean in the Midwestern United States. Commercialization of crops with 2,4-D or dicamba and glufosinate resistance will allow post-emergence (POST) applications of these herbicides. Therefore, information is needed on how 2,4-D/dicamba will interact with glufosinate in various rate combinations. The objectives of this study were to evaluate the interaction of glufosinate plus 2,4-D and/or dicamba for control of GR giant ragweed, and to determine their effect on GR giant ragweed density, biomass, maize injury, and yield. Field experiments were conducted in 2013 and 2014 in a field infested with GR giant ragweed in Nebraska, United States. The treatments included POST applications of glufosinate (450 or 590 g ai ha-1), 2,4-D, or dicamba at 280 or 560 g ae ha-1 applied alone and in tank-mixtures in glufosinate-resistant maize. The results showed that dicamba applied alone resulted in 56 to 62% and 73 to 83% control at 14 and 28 days after treatment (DAT), respectively, and ≥95% control at 60 DAT or at harvest compared to 17 to 30% and 57 to 73% control with 2,4-D applied alone at 280 and 560 g ai ha-1, respectively. Glufosinate tank-mixed with 2,4-D and/or dicamba consistently provided ≥89% control of GR giant ragweed, except that control with glufosinate plus 2,4-D varied from 80 to 92% at 60 DAT and at harvest. The comparison between the observed and expected control (determined by Colby’s equation) suggested an additive interaction between glufosinate and 2,4-D or dicamba for control of GR giant ragweed. Contrast analysis also indicated that GR giant ragweed control with glufosinate plus 2,4-D or dicamba was either consistently higher or comparable with individual herbicides excluding 2,4-D applied alone. Herbicide programs, excluding 2,4-D at 280 g ae ha-1, resulted in ≥80% reduction in GR giant ragweed density. Tank-mixing glufosinate with 2,4-D or dicamba showed an additive effect and will be an additional tool with two effective modes of action for the management of GR giant ragweed in maize.

Overlapping Residual Herbicides for Control of Photosystem (PS) II- and 4-Hydroxyphenylpyruvate Dioxygenase (HPPD)-Inhibitor-Resistant Palmer amaranth (Amaranthus palmeri S. Watson) in Glyphosate-Resistant Maize

“…Likewise, Crow et al ( 2016 ) reported >87% control of >20 cm tall Palmer amaranth with dicamba plus diflufenzopyr applied alone or in tank-mixture with glyphosate, mesotrione, tembotrione, mesotrione plus rimsulfuron, or tembotrione plus thiencarbazone at 4 WAPOST. Nonetheless, the dependence on POST herbicides with a single site of action must be avoided to prevent the evolution of HR weeds (Chahal and Jhala, 2015 ; Chahal et al, 2017 ; Ganie and Jhala, 2017b ). Furthermore, the confirmation of GR Palmer amaranth in a GR soybean/maize production field in south-central Nebraska signifies that dependence on a single POST herbicide program is not a reliable option (Chahal et al, 2017 ).…”

“…More recently, GR Palmer amaranth has also been confirmed in Nebraska (Chahal et al, 2017 ). In view of the widespread occurrence of six GR broadleaf weeds in Nebraska, tank-mixing glyphosate with other site of action herbicides and rotation of GR maize with other HR crop traits has become important to diversify the number of herbicide options for management of HR weeds such as Palmer amaranth (Ganie et al, 2017 ; Ganie and Jhala, 2017b ).…”

Effectiveness of alternative herbicides on three Conyza species from Europe with and without glyphosate resistance

“…The rapid resistance evolution to glyphosate highlights the relevance of implementing different weed management strategies (Ganie and Jhala, 2017). In general, the mixtures of the alternative herbicide with glyphosate showed additive effects, because synergistic interactions between agrochemicals are rare (Cedergreen, 2014), and it is more common to observe antagonistic effects of glyphosate mixed with herbicides, such as atrazine, cloransulam, dicamba, lactofen, and topramezone (Vidal et al, 2003;Harre et al, 2018).…”

“…The herbicide combinations with different modes of action, either in sequential application or tank-mix, can contribute to improve the control of resistant weeds (Tornisielo et al, 2013), and additionally, may also avoid or delay evolution of resistance (Ganie and Jhala, 2017). Improvements in weed control have been observed in glyphosate-resistant species by applying glyphosate tank-mix combinations (Riley and Bradley, 2014), in some cases, the control was improved by 25-30% compared to glyphosate alone (Eubank et al, 2008).…”

Multiple Resistance Evolution in Bipyridylium-Resistant Epilobium ciliatum After Recurrent Selection

“…The occurrence of bipyridylium resistance has led to an increase in the use of the herbicides glyphosate [5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibitor], glufosinate [glutamine synthetase (GS) inhibitor], 2,4-D (synthetic auxin), flazasulfuron [acetolactate synthase (ALS) inhibitor], and pyraflufen-ethyl [protoporphyrinogen oxidase (PPO) inhibitor] among others. Using numerous herbicides allows a broad herbicidal spectrum that includes activity against monocotyledonous and dicotyledonous weeds, and rapid onset of action and long persistence of some herbicides (Ganie and Jhala, 2017 ).…”