Biokinetic Analysis and Metabolic Fate of 2,4-D in 2,4-D-Resistant Soybean (Glycine max)

Abstract

The Enlist weed control system allows the use of 2,4-D in soybean but slight necrosis in treated leaves may be observed in the field. The objectives of this research were to measure and compare uptake, translocation, and metabolism of 2,4-D in Enlist (E, resistant) and non-AAD-12 transformed (NT, sensitive) soybeans. The adjuvant from the Enlist Duo herbicide formulation (ADJ) increased 2,4-D uptake (36%) and displayed the fastest rate of uptake (U= 0.2 h) among treatments. E soybean demonstrated a faster rate of 2,4-D metabolism (M= 0.2 h) compared to NT soybean, but glyphosate did not affect 2,4-D metabolism. Metabolites of 2,4-D in E soybean were qualitatively different than NT. Applying 2,4-D-ethylhexyl ester instead of 2,4-D choline (a quaternary ammonium salt) eliminated visual injury to E soybean, likely due to the time required for initial de-esterification and bioactivation. Excessive 2,4-D acid concentrations in E soybean resulting from ADJ-increased uptake may significantly contribute to foliar injury.

Physiological attributes of Enlist E3™ soybean seed submitted to herbicides application

“…Enlist E3™ cultivars are tolerant to 2,4-D, glyphosate and glufosinate herbicides, which contributes to the efficient management of weeds, especially those resistant to glyphosate. Soybean tolerance to 2,4-D herbicide was achieved by inserting a gene from Delfia acidovorans bacterium, which codes for the arylokyalkanoate dioxygenase isoenzyme (AAD), which metabolizes the 2,4-D to the non-herbicidal dichlorophenol metabolite (DCP) (Skelton et al, 2017). Considering the introduction of the herbicide tolerance the Enlist™ Duo Colex-D™ and Enlist™ Colex-D™ herbicides was also launched, which corresponds to the 2,4-D choline salta and mixture of glyphosate and 2,4-D choline, respectively.…”

Enlist volunteer corn affects the crop development and seed quality of Enlist soybean

“…Enlist TM technology is a new tool available for farmers in several countries to control glyphosate-resistant broadleaf weeds, conferring tolerance to 2,4-dichlorophenoxyacetic acid (2,4-D choline), glyphosate, and ammonium-glufosinate herbicides (Wright et al 2010;Skelton et al 2017). The tolerance to 2,4-D choline was obtained by the insertion of the aryloxyalkanoate dioxygenase (AAD-12 V1) coding-gene.…”

Selectivity of 2,4-D salts to barley plants applied at distinct phenological crop stages

“…However, the use of 2,4-D for weed control can cause injury to cereal crops such as barley. These effects are mainly related to the formulation and dose of the product, in addition to the crop development stage and soil and climate conditions at the time of application (Kumar & Singh, 2010;Peterson et al, 2016;Skelton et al, 2017).…”