03011nas a2200181 4500008004100000245011000041210006900151260000800220300001600228490000600244520233800250100002402588700001902612700001702631700001802648700003102666856013202697 2025 eng d00aDouble-encapsulated controlled release system for the staged delivery of a growth stimulant and herbicide0 aDoubleencapsulated controlled release system for the staged deli cAPR a1047–10560 v53 a

Weed control remains a critical challenge in agriculture, especially with parasitic weeds such as Orobanche spp., Striga spp., and Cuscuta spp., which significantly reduce crop yield. Although herbicides are effective against common weeds, they are less effective against parasitic weeds due to their unique germination mechanisms and close association with host plants. Growth regulators can stimulate the germination of parasitic weeds (suicidal germination) in the absence of host plants, providing a potential opportunity for controlling parasitic weeds, especially Striga sps. We report here a double-encapsulated staged delivery system, wherein herbicide (atrazine) is encapsulated in the inner polyurea shell and a growth stimulant (Gibberellic acid, GA3) in the outer alginate matrix. In vitro release study conducted in an aqueous medium showed that the time required for 50% release of atrazine from this double-encapsulated system is 96 h against 3 h for GA3. The quick release of GA3, followed by a slow and sustained release of atrazine, is expected to first induce the germination of parasitic weed seeds using GA3 and subsequently exterminate them upon exposure to atrazine. Interpretation of release data using the Weibull model led to the conclusion that the release of atrazine and GA3 is primarily governed by Fickian diffusion. Soil breakthrough profile shows that double encapsulation of atrazine helps to control the overleaching of atrazine into the soil.

1 aAher, Yogeshwar, P.1 aAdhikari, Benu1 aShukla, Ravi1 aMarimuthu, S.1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/double-encapsulated-controlled-release-system-staged-delivery-growth-stimulant-and-herbicide03949nas a2200217 4500008004100000245015000041210006900191260000800260300001100268490000700279520315700286100002003443700001803463700001603481700002303497700001903520700002203539700002003561700002103581856012903602 2025 eng d00aMoisture- responsive controlled-release herbicide system using guar gum and nano cellulose for sustainable weed management in rainfed agriculture0 aMoisture responsive controlledrelease herbicide system using gua cSEP a1065760 v273 a

Weed management poses a significant challenge in rainfed agricultural system, with chemical control being the predominant strategy due to its expeditious nature. However, the efficacy of herbicides in these systems is heavily dependent on optimal soil moisture, making the application of pre-emergence herbicides difficult due to erratic rainfall patterns. Sudden rainfall events post-sowing can result in sticky or muddy fields, complicating the application process and leading to infrequent use of pre-emergence herbicides in rainfed agriculture. To address these challenges, an innovative approach was developed involving the herbicide molecules entrapment in hydrogel matrices synthesized from biopolymers. This study focuses on the design and preparation of atrazine-loaded hydrogel using guar gum and nanocellulose, aimed at managing weeds in maize crops, which are prevalent in rainfed regions. The paper details the protocol for synthesizing the hydrogels and entrapment of atrazine, characterizing the formulations, and conducting pot validation trials to assess phytotoxicity and weed control efficacy compared to commercial atrazine application. The results demonstrated high water retention capacities and entrapment efficiency of the hydrogel for preferable application. FTIR analysis confirmed the presence of atrazine at 802 cm-1 and other excipients in the encapsulated formulations, while XRD analysis verified the presence of nanocellulose. The release pattern indicated a sustained and controlled release of atrazine from the hydrogels over 40 h in-vitro studies, compared to the complete dissolution of pure atrazine within three hours. Screening trial further validated the crop safety and improved weed control efficiency of the entrapped formulations relative to commercial atrazine. The encapsulated formulations using biopolymer-based hydrogels show promise as a viable alternative for weed management in rainfed agriculture, offering controlled herbicide release and improved application efficiency under variable moisture conditions.

1 aPrasanna, Jakku1 aMarimuthu, S.1 aGowtham, G.1 aShanmuganathan, K.1 aLakshmanan, A.1 aChandana, Pebbeti1 aKarthikeyan, S.1 aSomasundaram, E. uhttps://library.ncl.res.in/content/moisture-responsive-controlled-release-herbicide-system-using-guar-gum-and-nano-cellulose