Effect of Different NPK Levels on the Growth and Yield of Three Tomato (Solanum lycopersicum) Varieties in Sri Lanka

Experiments were conducted from June to August, 2016 in fields at Attampitiya and Walimada in Sri Lanka. The aim was to obtain growth and yield parameters of three tomato varieties under three levels of NPK fertilizers. Treatment consisted of two tomato varieties (Roma, Thilina, and T 245), five levels of NPK fertilizer (recommended dosage of inorganic fertilizers as a control dosage (T1), ½, ¾, 5/4 and 3/2 fold of the control treatment laid in a split-plot design with two replications. T-245 tomato variety proved superior over Roma and Thilina on growth characteristics. It was evident that increased NPK levels resulted in higher growth performance in all three tomato varieties. Elevated NPK level did not respond significantly to yield increase, implying that such additions are not necessary as they increase the cost of production in terms of high cost incurred for fertilizer and pollution.