Germinação, crescimento e produção de cultivares de pimentão sob estresse salino.

Abstract

Being common in the Northeast, water with varied concentrations of salts, it is important to identify tolerant genotypes to saline stress, allowing new options of cultivation for the farmers of the region. With this objective, this work was carried out aiming to evaluate the effects of different levels of the irrigation water salinity on germination, growth and production of three pepper cultivars. The experiment was conducted in the greenhouse belonging to the Department of Agricultural Engineering at the Center of Sciences and Technology of is UFCG. The experimental design was completely randomized with 18 treatments, characterizing a 6 x 3 factorial outline with three replications, with six levels of salinity in the irrigation water (Nl = 0.7; N2 - 1.4; N3 = 2.1; N4 = 2.8; N5 = 3.5 e N6 4.2 dS m"1) and three cultivars or pepper (Hard Pell, Yolo Wonder e All Big). The irrigation waters were prepared by addition of NaCl, to obtain the desired electrical conductivity (ECW). From the results obtained, it is concluded that the salinity affected more the index of emergency speed and the number of days to germinate than the percentage of germinated seeds. Tolerance differences were not found among the cultivars. The height of the plants, number of leaves, diameter of stem, dry phytomass of the leaves, of the stem, of the root and total, relation root/shoot and quantum efficiency photosystem II, had a linear decrease with the increase of the electrical conductivity of the irrigation water. The leaf area reduced in quadratic way with increase of ECW. In relation to production, the increment of the salinity affected negatively the number and length of fruits with decreases respectively of 17,18 and 7,81% for unitary increase of ECW, and reduction in the diameter of fruits. The mean and total green and dry phytomass of fruits decreased linearly with the increment of the salinity of the irrigation water. The mean and total content of water of fruits decreased 18,82 and 25,73% respectively with the unitary increase of ECW. The consumption of water for the plant decreased with the increment of the ECW.