The study was conducted in March-May 2020 in greenhouse in Erzincan Horticultural Research Institute. Sahra F1 variety of watermelon (Citrulus lanatus) was used as plant material in the experiment. In this study, the effects of different doses (0, 25, 50, 75, 100, 125, 150 and 175 ppm) of Tebuconazole substance on the quality and development of watermelon seedlings were investigated