Nitrogen-potassium ratios in fertirrigation for protected cultivation of tomato (Solanum lycopersicum L.) in Ferralitic Red Soil during the spring-summer period

Abstract

The present study had as objective to evaluate nutritious solutions with different relations between nitrogen and potassium in the productivity and fruits of tomato quality (hybrid HA 3019) in typical Red Ferralitic soil. The experience was developed in the �??Liliana Dimitrova�?� Horticultural Research during the spring-summer period of years 2006, 2008 and 2009. Four relations N:K2O (N:K) studied: (1:1.5, 1:2.0, 1:2.5 or variant of production and 1:3.0) distributed in a design of randomized blocks with four replicas. During the 2006 were not significant differences between relations N:K 1:2.0 and 1:2.5 as far as yield, nevertheless, during 2008 relation N: K 1:2.0 increased the extra + first and total yield in 19.50 and 18.47 % respectively in relation to the control treatment. In the validation experiment (2009) it was confirmed that a relation N:K of 1:2.0 allow to guarantee an appropriate yield formation during the spring - summer time, as well as to reduce the doses of K2O, CaO and MgO, with relationship to the control treatment (N:K 1:2.5) in a 19,11, 17,90 and 16,50 %, respectively. The relationship N:K 1:2.0 also allow to coordinate the best commercial and total yield with an appropriate external quality and life in shelf of the tomate fruits, expressed in a bigger hardness and endocarpio diameter, smaller percentage of fruits outside norm and inferior values of losses postharvest to the 7 and 17 days.