Influences of nitrogen and potassium fertilizer rates on pepper and tomato yield and nutrient uptake under field conditions

Abstract

The influence of nitrogen (N) and potassium (K) fertilizers on pepper (Capsicum annuum L.) and tomato (Lycopersicon esculentum Mill) growth, fruit production and nutrient uptake was determined under field conditions for two successive years. The aim of the experiment was to determine the optimum N and K fertilizer rate for yield and quality parameters. Experiments were carried out during the two consecutive growing seasons of 1997-1998 at the Agricultural Research Station of Cukurova University, Adana, Turkey. A split plot design with three replications was used with each block containing three treatments 0, 100 and 200 Kg ha-1 of N and K2O. Nitrogen was used as NH4NO3 and K used as K2SO4. Results revealed that the pepper and tomato plants have responded significantly (P< 0.001) to the nitrogen fertilizer (100 and 200 kg N ha-1) by increasing plant length, yield and nutrient content. However, potassium fertilizers have less effect on both plant parameters. Increasing N addition increased tomato and pepper plant yield, however increasing K addition did not make a significant (P< 0.277, 827 respectively) difference on the yield of either plant. Under high nitrogen and potassium fertilizer application, flowering time was earlier than that of the control plants. Nitrogen treatments increased the plant N, P and K concentration. The study showed that K fertilizer has no significant influence on nutrient concentration. Results have shown that pepper plants have a higher K content than tomato plants. Key words: Pepper, tomato, nitrogen, potassium, fertilizer, nutrient uptake.