Efficient Herbicide Delivery through a Conjugate Gel Formulation for the Mortality of Broad Leaf Weeds

Abstract

Carfentrazone-ethyl is embedded in guar gum to prepare a polymer–herbicide conjugate gel formulation for a sustained release of the active ingredient (a.i.). The sprayable gel formulation was optimized at 0.5% (w/v) concentration. Strong interactions of the prepared composition of the polymer–herbicide conjugate system are shown through spectroscopic techniques, depicting the peak broadening of hydrophilic −OH bonds in the herbicide at 1743 cm –1 , shifting to 1730 cm –1 in the polymer–herbicide sample. There is a broadening and shifting of the peak at 329 nm for the n → π* transition at 335 nm in the polymer–herbicide conjugate system in UV spectra. Differential scanning calorimetric measurements show a lowering of endothermic melting peaks to 242 and 303 °C in the polymer–herbicide conjugate. X-ray diffraction studies showed a sharp diffraction peak of the pure polymer at a 2θ of ∼20.3°, while broadening and shifting of the peak position to a 2θ of ∼20.8° were observed after adding the herbicide. Diffusion of the active ingredient in the polymer–herbicide conjugate resulted in much greater coverage (most of the weed leaf stomata (>95%)) than conventional spraying. The efficacy of both the polymer–herbicide formulation and herbicide at different doses in weed nurseries showed significantly higher weed mortality in Anagallis arvensis (95.4%), Chenopodium album (∼97%), and Ageratum conyzoides (93.16%) treated with the polymer–herbicide formulation @ 20 g a.i. ha –1 . Narrow SPAD readings range of A. arvensis (0.1–30.6) and that of C. album (0–5) were observed in the polymer–herbicide formulation @ 20 g a.i. ha –1 was at par with the conventional formulation @ 30 g a.i. ha –1 . Less regeneration in a weed nursery of A. arvensis (27%), C. album (77%), and A. conyzoides (49%) treated with gel formulations @ 20 g a.i. ha –1 was observed, which was significantly lower than those in conventional herbicides.

Weed Management in Wheat: A Review

“…Results have shown that injury is often caused to nearby broad leaf crops by the use of 2,4-D butyl ester because of its drifting and volatilization (Li et al, 2002). Recent studies have recommended the use of carfentrazone for controlling broad leaf weeds because of its fast action (Bhardwaj et al, 2022). Sometimes an herbicide is less effective against some weeds but has good efficacy for others.…”

Research Progress of a Pesticide Polymer-Controlled Release System Based on Polysaccharides

“…Diffusion of the active ingredient in the polymer-herbicide conjugate resulted in greater coverage (most weed leaf stomata (>95%)) compared to conventional spraying. In addition, the weed mortality of Anagallis arvensis (95.4%), Chenopodium album (~97%), and Ageratum conyzoides (93.16%) treated with the polymer was significantly increased [67]. Using a guar gum-g-cl-polyacrylate/bentonite hydrogel composite (GG-HG) and a guar gum-g-cl-PNIPAm nanohydrogel (GG-NHG) as carriers, imidazo-controlled release formulations of tobacco herbicides had a relatively long-term herbicidal effect [68].…”

Induced Piezoelectricity in Cotton-Based Composites for Energy-Harvesting Applications

“…The major demerit of these ceramic materials is their brittle nature and toxicity, which restricts its usage in biocompatible applications . Polymers have evolved as a remarkable material and are continuously growing as one of the most sustainable materials in various applications. − Piezoelectric polymers are one of the most effective and efficient materials for the PEH due to their enhanced mechanical properties, durability, and biological viability . Poly­(vinylidene fluoride) (PVDF) is one of most the remarkable polymers in terms of piezoelectric applications.…”