Manejo da fertirrigação potássica e cálcica na cultura do tomateiro cultivadas em ambiente protegido e submetidas ao estresse salino

Abstract

The production and fruit quality of the tomato crop is directly related to the water quality used in irrigation and to the adequate supply of nutrients, mainly potassium and calcium. This work was carried out in the Department of Environmental and Technological Sciences of the Federal Rural Semi-Arid University (UFERSA), in Mossoró, RN, Brazil. The objective was to evaluate the tomato cultivation (Lycopersicum esculentum Mill) in a protected environment using saline water irrigation In different concentrations, and fertirrigation with different potassium: calcium ratios. The experimental design was in randomized blocks, in a 5 x 4 factorial scheme, with four replications. The experiment was carried out in a protected environment and using a coconut fiber substrate. The treatments were formed by the combination of five ionic ratios of potassium and calcium (F1-K+/Ca2+ = 1.5: 1, F2- K+/Ca2+ = 1.25: 1, F3- K+/Ca2+ = 1: 1, F4- K+/Ca2+ = 1: 1, 25 and F5- K+/Ca2+ = 1:1,5), using standard solutions for each crop, according to specialized literature, with four levels of irrigation water salinity (S1-0.5, S2-2,0, S3-3,5 and S4-5,0 dS m-1). The ratio K+/Ca2+ = 1:1 corresponds to the concentration of these nutrients recommended for the culture in hydroponic cultivation. The plants were evaluated for growth variables (height, stem diameter, number of seeds, number of seeds, number of seeds) (Number of fruits per plant, mean mass of fruits and fruit yield per plant). The K+/Ca2+ ratios studied did not mitigate The effect on the analyzed variables The use of low K+/Ca2+ ratios potentiated the effect of salinity on the plants