Doses de nitrogênio influenciando a redução do estresse salino no Meloeiro.

Abstract

The muskmelon is a crop that adapts well to the soil and climate conditions of the northeastern region of Brazil, which makes it extremely important for producers because of its high productivity, income and jobs generated. However, under conditions of the northeastern semi-arid region, due to the scarcity of good quality water, this oilseed crop has been cultivated with high salinity water, which can lead to a reduction in productivity and fruit quality. The objective of this work was to evaluate the production and quality of the muskmelon fruits when submitted to the application of nitrogen doses in plants cultivated with high salinity water. The experiment was carried out in a experimental area located in the Center of Sciences and Technology Agrifood (CCTA) of the Federal University of Campina Grande (UFCG) during the period from June to December 2017, allocated in a randomized complete block design with five replicates. The treatments were composed of different doses of nitrogen in the form of calcium nitrate (5, 10, 15, 20 and 25 g.plant-1) during the culture cycle. The muskmelon hybrid Hy Mark of the Cantaloupe group, cultivated at 2.0 x 0.4 m spacing and the plants were irrigated with saline water at a concentration of 4.0 dS.m-1. The characteristics evaluated during the experiment and the harvest were related to the floral development, fruit production and quality. The use of calcium nitrate at higher doses of 25.0 g.plant-1 reduced the number of flowers in the plant. It was evidenced that the competition between nitrate and chloride ions was effective for the characteristics related to the production and quality of the fruits at least up to a certain limit. The number of fruits, fruit mass, total productivity and soluble solids content presented a quadratic response and their values increased by 15.6, 9.1, 23.8 and 8.8% when the dose of calcium nitrate of 5.0 for the optimal doses of 18.2, 15.5 and 17.6 and 16.0 g.plant-1.