This research was conducted under greenhouse conditions to evaluate the optimum combination of irrigation and fertilizer levels to attain the best yield and quality of tomato crop. The experiment was conducted by using a split-plot design with three replicates. Irrigation levels were applied to the main plots and fertilizer levels to the sub-plots. For each experimental unit, the irrigation levels were W1=8 mm/day, W2=7 mm/day, W3=6 mm/day, and W4=5 mm/day. Fertilizers treatments varied during the growing season. For the period after transplanting till flowering, the treatments consisted of weekly applications of F1=(N1, P1, K1, respectively, 9.8, 6.13, 7.35 g/plot), F2=(N2, P1, K1, respectively,14.7, 6.13, 7.35 g/plot), F3=(N2, P2, K1, respectively, 14.7, 9.19, 7.35 g/plot), and F4=(N2, P2, K2, respectively, 14.7, 9.19, 11.0 g/plot). Fertilizer levels were increased as the plants developed during the growing season. Plant height and the number of flowers per tomato plant were measured during the growing season and at harvesting time. Random samples of tomato leaves and fruits were taken from each experimental plot to determine the percentage of dry matter, total nitrogen, phosphorus, and potassium contents of fruits and leaves. Total yield during harvesting period and average fruit weight were also measured. Results indicated that irrigation and fertilizer levels had significant effects on the number of flowers per plant and W1F2 combination was significantly the most effective treatment compared to the other treatments. Plant height was not affected significantly by any treatment. The total yield significantly increased in W3F1 treatment. Average fruit weight was significantly higher in W2F3 as compared to the other treatments. The percentage of dry matter was significantly affected by the treatment W3F3 in both leaves and fruits. Total leaf contests of nitrogen, phosphorus, and potassium significantly increased in W2F4 treatment. Total nitrogen content in tomato fruits did not show any significant difference among different treatments, whereas fruit phosphorus and potassium contents significantly increased in W2F3 and W4F4 treatments.
