effects of different levels of supplementary nitrogen and potassium in nutrient solution on yield and leaf n and k concentrations of tomato

the effects of different levels of nitrogen (100, 200, 300 and 400 mg/l) and potassium (125, 250 and 375 mg/l) on yield and leaf n and k concentrations of tomato were investigated in perlit culture using a factorial randomized design with three replications. the highest fruit yield was obtained with 200 mg/l n. higher levels of nitrogen decreased tomato yield. with increasing nitrogen concentration in nutrient solution, n content of leaf increased significantly whereas leaf k concentration decreased. different potassium levels had no significant effect on tomato yield. with increasing potassium levels of nutrient solution, concentration of leaf n decreased significantly whereas concentration of leaf k increased. the greatest and the least fruit yields were obtained from n200k250 and n400k375 treatments, respectively. the highest and the lowest concentrations of leaf n were observed in n400k125 and n100k375 treatments, respectively. the greatest and the least concentrations of leaf k were observed in n100k375 and n400k125 treatments, respectively.