Investigation on the efficacy of Glyphosate against amaranthus palmeri S. watson's in different water volume, water quality, application technique and intraday application times conditions

Investigation on the efficacy of glyphosate against Amaranthus palmeri S. Watson in different water volume, water quality, application technique and intraday application times conditions Objective: In this study it was aimed to investigate the effects of water quality, water volume, ammonium-sulphate additive, spray equipment as well as intraday treatment timing on the efficacy of glyphosate herbicide on Amaranthus palmeri. Materials and Methods: In the experiments carried out under greenhouse and field conditions glyphosate was applied in three different water quality, two different water volume, two different spray equipment and under different intraday timings having different climatic conditions. Effects of these treatments were evaluated by visual estimations as well as fresh and dry weights of weed. Results: In pot experiments it was observed that all conditions affected the glyphosate efficacy at lower doses. At the recommended dose however no effect of the factors was observed. Low water volume, high quality water with lower hardness improved the efficacy of glyphosate. Ammonium sulphate additive caused slight increase in the efficacy. As the result of intraday treatment timing highest effect was obtained under high relative humidity or temperature conditions. Conclusion: A. palmeri is an important threat with high invasive capacity. But this weed has not yet distributed most parts of our country. With this reason eradication should be the first measurement which should be immediately taken. Results of these studies showed that glyphosate is not a suitable herbicide even under optimized treatment conditions. Therefore mechanical control and alternative herbicides should be used to control this weed. Key words: Glyphosate, Amaranthus palmeri, treatment conditions, herbicide