Desenvolvimento vegetativo do tomate cereja em substrato sob influência de diferentes lâminas de irrigação com água salina em cultivo protegido

Abstract

The objective of this work was to evaluate the vegetative development of cherry tomato (Lycopersicum esculentum var. cerasiforme) cultivated in substrate, under the influence of irrigation at different water salinity levels in protected cultivation. The experiment was performed in a entirely randomized design, bifatorial 5x3 for the factors salinity levels and irrigation schedules, with four repetitions. The factors were composed of three irrigation slopes (80, 100 and 120% of Etc) and five water salinity levels (0.2; 0.45; 3; 5 e 7 dS m-1). The seeds used were Hortasul® brand with purity of 99% and germination of 94%. The seeds were placed in three plastic basins allocated in the greenhouse, which were filled with commercial SoilMax® substrate. The sowing was performed in basins perforated at the base and filled with commercial SoilMax® substrate. Hortasul® seeds with 99% purity and 94% germination were used. The seedlings were transplanted at 30 DAS into plastic pots with a capacity of 11 liters. The irrigation sheets were defined according to the methodology of irrigation management by Class A Tank. The salinity levels of the irrigation water were achieved by diluting sodium chloride (NaCl) in distilled water until the electrical conductivity levels of each treatment were found. The following characteristics were observed: plant height (cm), number of leaves and leaf area (cm2). Statistical analysis was performed using the SISVAR software, based on a bifactor experimental design, where the interaction between the two factors: irrigation strips and water salinity levels will be tested by the F test, at 5% probability of error. The effects of irrigation and water salinity levels were submitted to regression analysis in order to adjust equations. There was no significant difference in iteration between the factors irrigation schedule and water salinity levels for the parameters plant height (cm), number of leaves and leaf area (cm2). The different irrigation sheets used, 80%, 100% and 120% of the crop evapotranspiration did not show significant statistical effects on the variables evaluated. The levels of water salinity, 0.2; 0.45; 3; 5 e 7 dS m-1, were significant only for the number of leaves variable, but not for plant height and leaf area. It was found in function of the irrigation blade, the MET for plant height in 98,42% of Etc, with 34,88 cm; for number of leaves in 98,42% of Etc with 34 leaves; and for leaf area in 90,83% of Etc with 9,10 cm2. It was found, as a function of salinity levels, the MET for plant height at 1.45 dS m-1 com 21.53 cm; for leaf number at 2.37 dS m-1 with 31 leaves; and for leaf area at 14.16 dS m-1 com 9.58 cm2. Keywords: Protected environment, salinity, irrigation management, cherry tomato.