Optimizing foliar activity of glyphosate on Bidens frondosa and Panicum maximum with different adjuvant types

Abstract

The in¯uence of non-ionic (X-77) and organosilicone (L-77) adjuvants and of methylated seed oil (MSO) on the uptake, translocation and ecacy of glyphosate was investigated in Bidens frondosa L. and Panicum maximum Jacq. In addition, the physicochemical properties of adjuvants and adjuvant + glyphosate aqueous solutions were determined. Signi®cantly lower surface tension and contact angle values were obtained with aqueous solutions of L-77 alone and with glyphosate. Over a 48-h time course, it was observed that >50% of applied 14 C-glyphosate was absorbed within 15 min in B. frondosa with L-77. At 6 h and thereafter, 14 C glyphosate absorption was signi®cantly higher with MSO compared with X-77 in B. frondosa. In P. maximum, uptake and translocation of 14 C-glyphosate + adjuvant were increased in general up to 48 h after treatment application, except with L-77, which showed no improvement in uptake ± instead there was a signi®cant reduction compared with no treatment with L-77. This indicated its antagonistic eect on this grass species. The lower values of 14 C-glyphosate in P. maximum also con®rmed that adjuvant eects were species speci®c. In the ecacy studies, glyphosate formulated with L-77 achieved signi®cantly higher control of B. frondosa, while there was no control of P. maximum with this treatment. This con®rmed antagonism in glyphosate absorption into P. maximum by L-77. Furthermore, signi®cantly higher control of tested plants was recorded with MSO in comparison to X-77, which con®rms the solubilizing or humectant nature of MSO.

Green nanoemulsion‐laden glyphosate isopropylamine formulation in suppressing creeping foxglove (A. gangetica), slender button weed (D. ocimifolia) and buffalo grass (P. conjugatum)

“…Nanoemulsions have been reported to increase the penetration of incorporated drugs distinctly for oral, topical and intravenous administration . The use of vegetable‐oil‐based adjuvant has been shown to improve the penetration of many herbicides, including glyphosate IPA , . There is evidence that organosilicone wetting agents could enhance the absorption of the herbicide primisulforon into plant tissue, with greater weed control .…”

The Mechanism of Methylated Seed Oil on Enhancing Biological Efficacy of Topramezone on Weeds

“…There is a strong correlation between the translocation and the absorption of a herbicide in the plants [14], [16], [43]. In this study, MSO significantly increased absorption and translocation of topramezone for giant foxtail, but it significantly increased only absorption of this herbicide but not translocation for velvetleaf.…”

“…Xu et al reported that MSO could decrease the surface tension and contact angle and then increase the wetted areas of droplets on both waxy and hairy leaves [7], [8]. Some reports have shown that MSO enhances the efficacy of several herbicides on certain weed species by increasing the absorption of the herbicides by weeds [9], [10], [11], [12], [13], [14], [15], [16]. Topramezone, a hydroxyphenylpyruvate dioxygenase inhibitor, was commercially introduced in the year of 2006 [17].…”

Glyphosate Efficacy of Different Salt Formulations and Adjuvant Additives on Various Weeds

“…In another study, Sharma and Singh [50] evaluated the influence of non-ionic (X-77) and organosilicone (L-77) adjuvants and methylated seed oil (MSO) on the uptake, translocation and efficacy of glyphosate in Bidens frondosa L. and Panicum maximum Jacq. In B. frondosa, all three adjuvants significantly increased the uptake and translocation of glyphosate.…”