Effects of different levels of irrigation and nitrogen interactions on yield and water productivity in watermelon irrigated by drip method

Water and nitrogen (N) are the main determinants affecting watermelon plants' vegetative and generative growth. This study aimed to determine the yield response and water-yield relationships of watermelon plants grown in Bursa ecological conditions and clay soils under different irrigation and N levels. Four irrigation levels (IR-100, IR-75, IR-50, and IR-25) and five N ratios (kg ha-1) (N0, N75, N150, N225 and N300) were considered as experimental treatments. In the study, a split-plot experimental design was used. While irrigation water was applied to thetreatments between 214 and 603 mm, actual crop evapotranspiration varied between 288 and 687 mm. Among the irrigation treatments, the IR-100 yielded the highest fruit yield. With the decrease in irrigation levels, the yield also decreased. Fruit yield, weight, and size increased to a N level of 225 kg ha-1 and decreased at higher levels. Irrigation and N interaction showed a statistically significant effect (p