Produção e conservação láctica do tomate cereja sob irrigação com águas salinas e adubação nitrogenada.

Abstract

The use of saline water combined with management strategies that mitigate the effects of salts on plants is an alternative in view of the low availability of good quality water in the Brazilian semiarid region and the lactic conservation of these fruits is also of great importance to ensure greater quality post-harvest. In this sense, the objective was to evaluate the production and lactic conservation of cherry tomato irrigated with saline water and nitrogen fertilization, in the semiarid region of Paraíba. The experiment was conducted in two stages, the first under field conditions at the Center for Agrifood Science and Technology - UFCG, Pombal-PB, using a randomized block design, in a 5 x 5 factorial scheme, referring to five levels of electrical conductivity of irrigation water - CEa (0.3; 1.3; 2.3; 3.3 and 4.3 dS m-1) and five doses of nitrogen - DN (50; 75; 100; 125 and 150% of the recommendation for the crop), with 3 replications and one plant per plot, totaling 75 experimental samples. The second stage was carried out in a completely randomized design with a 6 x 5 factorial scheme, through the lactic conservation of the fruits produced in the first stage under six lactic conservation formulations (F1 - 100 g L-1 NaCl, F2 -100 g L-1 CaCl2 , F3 - 100 g L-1 KCl, F4 - 50 g L-1 NaCl: 50 g L-1 CaCl2, F5 - 50 g L-1 CaCl2: 50 g L-1 KCl and F6 - 50 g L-1 NaCl :50 g L-1 KCl) and the five levels of water salinity, with 3 repetitions, with the analyzes carried out in triplicate. The increase in irrigation water salinity and N doses induced stomatal closure and, consequently, reduced transpiration and CO2 assimilation rate in cherry tomatoes. There was an intensification in the effect of salinity on phytomass as a function of the increase in nitrogen doses. Irrigation with water with electrical conductivity of 2.3 dS m-1 provided higher levels of soluble solids, soluble solids/titratable acidity and chlorophylls a and b in cherry tomato fruits preserved in the formulation with 50 g L-1 NaCl:50 g L-1 KCl. The formulations of brine for lactic preservation containing 100 g L-1 NaCl and 100 g L-1 CaCl2 provided higher levels of vitamin C and flavonoids in cherry tomato fruits regardless of the salinity of the irrigation water.