Sodium-potassium interaction on growth, yield and quality of tomato in ultisol

The interaction of sodium (Na) and potassium (K) on growth, yield, nutrients and citric acid composition of fruit of tomato (Lycopersicon lycopersicum [L.] Karst) was investigated. Six rates of Na at 0, 2, 4, 8, 16 and 32 mgkg −1 soil and four rates of K at 0, 32, 64 and 128 mgkg −1 soil, applied as NaCl and KCl, respectively, were arranged in a randomized complete block design and replicated three times. Plant growth rate, number of flowers and fruit yields, nutrient composition and citric acid content of fruit juice were determined. The application of 2-4 mg Na kg −1 soil with 32-64 mg K kg −1 soil increased fruit yield by about 100%. Fruit yield correlated positively with the number of leaves (0.65***), number of flowers (0.57**) and shoot-N (0.40*). Sodium applied at Na:K ratio of 1:8 to 1:32 increased the growth and yield of the tomato plant.