Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 14 4 2012 07 01 Water and Nitrogen Application Levels for the Optimum Tomato Yield and Water Use Efficiency 889 902 15130 EN A. Ertek Department of Irrigation, Faculty of Agriculture, Süleyman Demirel University, 32260, Isparta,Turky. I. Erdal Department of Soil Science, Faculty of Agriculture, Süleyman Demirel University, 32260, Isparta,Turky. H. I. Yilmaz Department of Irrigation, Faculty of Agriculture, Süleyman Demirel University, 32260, Isparta,Turky. U. Senyigit Department of Irrigation, Faculty of Agriculture, Süleyman Demirel University, 32260, Isparta,Turky. Journal Article This study was conducted to determine the effects of different water and nitrogen application levels on drip-irrigated tomato plants. The amount of water usage was based upon the pan evaporation from a screened (class “A”) evaporation pan. The treatments consisted of two irrigation intervals (I1= 5 days and I2= 10 days), three plant-pan coefficients (Kcp1= 0.50; Kcp2= 0.75 and Kcp3= 1.00) and three nitrogen (N) levels (N0 = 0, N1= 80 and N2= 160 kg ha-1). The I, Kcp and N levels affected the tomato yields and water usage efficiencies, however the effects of nitrogen applications were found to be greater than those of the other applications. Consequently, to reach the maximum tomato yields under similar climate and soil conditions, plant-pan coefficients (Kcp) and nitrogen values should be equivalent to 1.00 and 160 kg ha-1, respectively. https://jast.modares.ac.ir/article_15130_44500587629a61f9c6ad74ec7cf4d5c6.pdf