Effect of water volume and water quality on the efficacy of glyphosate on some important weed species in Turkey

Abstract

The effect of spray water volume and water quality on the performance of three Roundup formulations were investigated in pot experiments to observe whether these factors influence the efficacy of herbicide on three important weed species occurring in Turkey. Sorghum halepense, Cyperus rotundus and Portulaca oleracea were used in the experiments. All Roundup formulations were applied at three different doses with two water volume rates (200 and 600 l/ha) and three different water qualities (clean water, clean water + CaCl2 to simulate hard water and water of Büyük Menderes River). Experiments were carried out at the research station of Adnan Menderes University in the Aydin province of Turkey and replicated twice. Results of the studies showed that the performance of Roundup on weeds was not influenced by herbicide formulation, but significantly affected by water volume as well as water quality. However, the effect of these factors was variable depending on the weed species and the applied herbicide dose. Significant differences were observed mostly at reduced doses more apparently in the case of more sensitive weed species such as P. oleracea and S. halepense. C. rotundus was more tolerant against herbicide so that an influence of investigated factors on the efficacy was observed even with the recommended dose. In general, low volume treatments (200 l/ha) provided significantly higher weed control. Similarly, clean water improved the effectiveness of the herbicide on weeds. These results suggest that using clean spray water and low volume treatments improve the efficacy of glyphosate at the recommended and reduced rates depending on the sensitivities of weed species.

Keywords

• Cyperus rotundus
• Formulierung
• Portulaca oleracea
• Sorghum halepense
• formulation