Potassium fertilization via fertigation and conventional application on quality of tomato fruits

ABSTRACT The tomato crop plays an important environmental, economic and even social role, especially for creating employment and income. The present work aims to evaluate the effects of potassium (K) drip fertigation and of conventional K fertilization on the tomato crop quality. The experiment was conducted under field conditions, in the period between August 2011 and December 2011, in Fortaleza, CE, Brazil. The experimental design was in randomized blocks in a factorial arrangement and the treatments corresponded to doses (D1 = 200, D2 = 400 and D3 = 800 kg K2O ha-1) and K fertilizing methods (F1 - Fertigation and F2 - Conventional fertilization), plus an additional control (without K fertilization) for each fertilizing method, with four replicates. The following variables were analyzed: fruit firmness (FF), soluble solids content (SS), titratable acidity (TA), pH and SS/TA ratio. K fertilization through fertigation (400 kg K2O ha-1) increases SS and the SS/TA ratio of the tomato fruits. Thus, K fertigation is the most promising method, since it allows the use of a lower K dose