University of Tabriz Journal of Agricultural Science and Sustainable Production 2476-4310 36 1 2026 04 20 Water Use Efficiency of Three Potato Cultivars (Solanum tuberosum L.) Under Weed Competition and Drought Stress Water Use Efficiency of Three Potato Cultivars (Solanum tuberosum L.) Under Weed Competition and Drought Stress 183 195 21431 10.22034/saps.2024.61424.3214 FA Ali Babazadeh Anari Plant Genetics and Production Engineering, Faculty of Agriculture and Natural Resources, Mohaghegh Ardabili University, Ardabil, Iran Hamid Reza Mohammaddoust Department of Agronomy, Faculty of Agriculture and natural resources, University of Mohaghegh Ardabili Davoud Hassanpanah Horticulture Crops Research Department, Ardabil Agricultural and Natural Resources Research Centre, AREEO, Ardabil, Iran. Yusef Jahani - Instructor at the Agricultural Research Center (Potato Station) of the Ardabil Agricultural Jihad Organization Journal Article 2024 04 29 <strong>Background and </strong><strong>Objectives: </strong>Potato is one of the important crops, which water deficit and weed competition   are two important challenges. Weeds can potentially extract a comparable or even greater amount of water from deeper soil layers than potato and intensify drought stress. The purpose of this research was to investigate the ability of potato cultivars to tolerate moisture stress and evaluate the efficiency of water use in the conditions of competition with weeds.<br /> <br /><strong>Materials and Methods: </strong>This research was conducted in 2023 in research center of Ardabil, as split factorial on a randomized complete block design in three replications. The studied factors were three levels of drought stress (0, 25 and 50% stress) as the main factor, two levels with and without weeds and three potato varieties (Agria, Rona and Tekta) as sub factors. Potato cover and potato height were mastered at flowering stage, and yield components were mastered at end season.<br /> <br /><strong>Results</strong><strong>: </strong>The results showed that Tekta and Agria varieties had the highest cover and height in flowering stage, respectively. In no drought stress, the Rona variety had the highest tuber number per plant, on the contrary, in drought stress condition, the Agria variety had more tuber number. In 50 stress conditions, weed competition reduced potato yield more than 2 times compared to no stress conditions. The results showed that the Agria cultivar had the highest WUE with 11.8 and 10.1 in the conditions of no competition and weed competition, respectively.<br /> <br /><strong>Conclusion: </strong>The results of this study showed that different potato cultivars have different tolerance to drought stress and the effect of weed competition on them is different under drought stress conditions. The results showed that the effect of weed competition on crop is more intense in water deficit condition, and because of this, water use efficiency decreases. <strong>Background and </strong><strong>Objectives: </strong>Potato is one of the important crops, which water deficit and weed competition   are two important challenges. Weeds can potentially extract a comparable or even greater amount of water from deeper soil layers than potato and intensify drought stress. The purpose of this research was to investigate the ability of potato cultivars to tolerate moisture stress and evaluate the efficiency of water use in the conditions of competition with weeds.<br /> <br /><strong>Materials and Methods: </strong>This research was conducted in 2023 in research center of Ardabil, as split factorial on a randomized complete block design in three replications. The studied factors were three levels of drought stress (0, 25 and 50% stress) as the main factor, two levels with and without weeds and three potato varieties (Agria, Rona and Tekta) as sub factors. Potato cover and potato height were mastered at flowering stage, and yield components were mastered at end season.<br /> <br /><strong>Results</strong><strong>: </strong>The results showed that Tekta and Agria varieties had the highest cover and height in flowering stage, respectively. In no drought stress, the Rona variety had the highest tuber number per plant, on the contrary, in drought stress condition, the Agria variety had more tuber number. In 50 stress conditions, weed competition reduced potato yield more than 2 times compared to no stress conditions. The results showed that the Agria cultivar had the highest WUE with 11.8 and 10.1 in the conditions of no competition and weed competition, respectively.<br /> <br /><strong>Conclusion: </strong>The results of this study showed that different potato cultivars have different tolerance to drought stress and the effect of weed competition on them is different under drought stress conditions. The results showed that the effect of weed competition on crop is more intense in water deficit condition, and because of this, water use efficiency decreases. https://sustainagriculture.tabrizu.ac.ir/article_21431_208c57ac27ebff2602fdedd34ff2f0c5.pdf