title: Release behavior and bioefficacy of imazethapyr formulations based on biopolymeric hydrogels.
abstract: Controlled release formulations of imazethapyr herbicide have been developed employing guar gum-g-cl-polyacrylate/bentonite clay hydrogel composite (GG-HG) and guar gum-g-cl-PNIPAm nano hydrogel (GG-NHG) as carriers, to assess the suitability of biopolymeric hydrogels as controlled herbicide release devices. The kinetics of imazethapyr release from the developed formulations was studied in water and it revealed that the developed formulations of imazethapyr behaved as slow release formulations as compared to commercial formulation. The calculated diffusion exponent (n) values showed that Fickian diffusion was the predominant mechanism of imazethapyr release from the developed formulations. Time for release of half of the loaded imazethapyr (t1/2) ranged between 0.06 and 4.8 days in case of GG-NHG and 4.4 and 12.6 days for the GG-HG formulations. Weed control index (WCI) of GG-HG and GG-NHG formulations was similar to that of the commercial formulation and the herbicidal effect was observed for relatively longer period. Guar gum-based biopolymeric hydrogels in both macro and nano particle size range can serve as potential carriers in developing slow release herbicide formulations.
authors.affiliation: a Division of Agricultural Chemicals , ICAR-Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Vikas
authors.initials: V
authors.lastname: Kumar
authors.affiliation: a Division of Agricultural Chemicals , ICAR-Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Anupama
authors.initials: A
authors.lastname: Singh
authors.affiliation: b Division of Agronomy , ICAR-Indian Agricultural Research Institute , New Delhi , India.
authors.forename: T K
authors.initials: TK
authors.lastname: Das
authors.affiliation: a Division of Agricultural Chemicals , ICAR-Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Dhruba Jyoti
authors.initials: DJ
authors.lastname: Sarkar
authors.affiliation: a Division of Agricultural Chemicals , ICAR-Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Shashi Bala
authors.initials: SB
authors.lastname: Singh
authors.affiliation: a Division of Agricultural Chemicals , ICAR-Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Dhaka
authors.affiliation: c Division of Design of Experiments , ICAR-Indian Agricultural Statistics Research Institute , New Delhi , India.
authors.forename: Anil
authors.initials: A
authors.lastname: Kumar
mesh_terms: D000180:Acrylic Resins; D000538:Aluminum Silicates / Q000737:chemistry; D001546:Bentonite / Q000737:chemistry; D000077215:Clay; D004058:Diffusion; D005685:Galactans / Q000737:chemistry; D006540:Herbicides / Q000737:chemistry / Q000493:pharmacokinetics*; D020100:Hydrogels / Q000737:chemistry*; D007194:India; D007700:Kinetics; D008351:Mannans / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry; D009539:Nicotinic Acids / Q000737:chemistry / Q000493:pharmacokinetics*; D010316:Particle Size; D053149:Plant Gums / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D005685:Galactans; D006540:Herbicides; D020100:Hydrogels; D008351:Mannans; D009539:Nicotinic Acids; D053149:Plant Gums; D001546:Bentonite; C052970:poly-N-isopropylacrylamide; C093630:imazethapyr; C007894:guar gum; D000077215:Clay
keywords: Guar gum; hydrogel clay composite; imazethapyr; nano hydrogel; slow release