Influência da fertirrigação potássica na produção de alface americana (Lactuca sativa cv. ‘Lucy Brown’) em Dourados - MS

Abstract

The experiment was conducted to evaluate the effect of concentrations of potassium chloride applied by fertigation on the development and production of lettuce (Lactuca sativa L.) cultivar Lucy Brown in an Dystroferric Red oxisol, in Dourados - MS. The experiment was conducted from september to november 2011 at the experimental field of Irrigation and Drainage Universidade Federal da Grande Dourados. The experimental design was a randomized block with four replications. The irrigation system was the type localized and drip irrigation management was via tensiometry. The treatments consisted of six concentrations of K2O (0; 15; 30; 45; 60 and 75 kg ha-1), provided by potassium chloride, being split in four applications for coverage to 30, 35, 40 and 45 days after transplantation. The characteristics evaluated were: fresh, fresh mass of marketable heads, stem fresh weight, number of inner leaves, number of outer leaves, total and commercial yield. Data were subjected to analysis of variance and regression studies. We observed significant effects of concentrations of K2O on all variables in level 1 and 5% probability by F test, with the exception of the number of inner leaves. Potassium chloride promoted greater vegetative development, mainly raising business productivity and commercial head fresh weight, the most desirable features in the marketing of lettuce.