Evaluation of different doses of Glufosinate Ammonium 13.5% SL for broad-spectrum weed control in Tea under Assam condition

Abstract

 Field experiment was conducted at Jorhat, Assam with a view to study the efficacy of Glufosinate Ammonium 13.5% SL in controlling weeds in tea plantation. The major weed florae present in the experimental plots were grasses (Axonopus compressus (Sw.) Beauv., Paspalum conjugatum Berg.), sedge (Kyllinga brevifolia Rottb.) and broad leaf (Borreria hispida (L.) K. Schum., Ageratum conyzoides Linn., Eupatorium odoratum Linn.) weeds. The experiment was laid out in a randomised block design with 3 replications and 7 treatments. Treatment comprised 5 different doses of Glufosinate Ammonium 13.5% SL (1500, 2000, 2500, 3300, 4100 ml ha^-1) compared with Glyphosate 41% SL @ 2500 ml ha^-1 as standard herbicide and one untreated control. Results revealed that among the treatments, application of Glufosinate Ammonium 13.5% SL @ 3300 ml ha^-1 and @ 4100 ml ha^-1 effectively controlled all the weeds in tea upto 60 days after application (DAA) of treatments. Therefore, both the doses of Glufosinate Ammonium 13.5% SL were equally effective and there was no significant difference between two treatments in terms of weed density and dry weight. No weed growth was observed upto 60 DAA of both the doses irrespective of weed species and 100 per cent weed control efficiency (WCE) was observed under these treatments. In case of controlling monocot weeds, Glufosinate Ammonium 13.5% SL @ 3300 ml ha^-1 and @ 4100 ml ha^-1 were statistically at par with Glyphosate 41% SL @ 2500 ml ha^-1 (standard). Considering the requirement of herbicide, its effectiveness against diverse weed florae and phytotoxicity on tea crop, Glufosinate Ammonium 13.5% SL @ 3300 ml ha^-1 is the best dose to manage the weeds in tea plantation.