Ecofisiologia e qualidade de frutos de quiabeiro cultivado com águas salinas e adubação nitrogênio-potássio.

Abstract

The use of saline waters in the Brazilian Semi-Arid region has been intensified, as it presents itself as an alternative to supply the water scarcity of this region. However, the excess of salts present in the water reduces the growth and production of crops. Thus, fertilization combined with nitrogen-potassium can be used as a strategy capable of mitigating the deleterious effects of salt stress on okra, with great socioeconomic potential for the Northeast region of Brazil. Therefore, the objective was to evaluate the growth, photosynthetic efficiency and fruit quality of okra irrigated with waters of different salinity fertilized with combinations of nitrogen and potassium. The experiment was carried out in the field, at the Center for Science and Agri-food Technology at the Federal University of Campina Grande, located in the municipality of Pombal-PB, in a randomized block design, with the treatments arranged in a 5 x 5 factorial scheme, referring to at five salinity levels of the irrigation water (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and five fertilizer combinations with nitrogen and potassium (0:40; 70: 60; 100: 80; 130: 100) 160:120% of the recommendation for testing in pots, with three replications, each experimental plot consists of a pot adapted as a lysimeter with a capacity of 25 L with a useful plant. Okra plants were evaluated for gas exchange characteristics, growth, photosynthetic pigments, water potential and physicochemical quality of the fruits. The combinations of 40% N + 40 K2O attenuated the deleterious effect of the salts to the level of 1.7 dS m-1 with the minimum of losses for the analyzed variables.