Evaluation of Bio - Efficacy and Phytotoxicity of Glyphosate 41% SL against Weed Flora in Grape Vineyards

The study was evaluated for the bio- efficacy and phytotoxicity of Glyphosate 41% SL against the complex weed flora in grapevines. The experiment was carried out at ICAR- NRC Grapes, Pune with seven treatments replicated thrice. The treatments were imposed at 3-4 leaf stage of weeds in vineyards. All the weed population were niformly distributed in vineyards.  All the treatments significantly reduced weed density over untreated control. The highest weed density was recorded with untreated control while, the negligible weed density was recorded in hand weeding followed by Glyphosate 41 % SL @ 4000 ml/ha at 15th, 30th, 45th Days after application. Least dry weight (g/m2) as recorded with Glyphosate 41 % SL @ 4000 ml/ha followed by Glyphosate 41 % SL @ 3000 ml/ha whereas, the maximum dry weight of weed (g/m2) was recorded with untreated control at 45th Days after application.  Highest weed control efficacy (%) was recorded with Glyphosate 41 % SL @ 4000 ml/ha followed by Glyphosate 41 % SL @ 3000 ml/ha whereas, negligible weed control efficacy (%) Was recorded with untreated control. The highest yield (kg/vines) was recorded with hand weeding treatments followed by Glyphosate 41 % SL @ 4000. The highest benefit: cost ratio was recorded in the treatment Glyphosate 41 % SL (4000 ml/ha) (1:1.99), while least in control treatment (1:1.77). Applications of Glyphosate 41 % SL @ 4000 ml/ha in grapevines showed highest weed control efficacy (%) and yield per vine (kg/vine) in this investigation.