PRODUCTION AND WATER CONSUMPTION OF EGGPLANT UNDER SALT STRESS AND CONTINUOUS DRIP AND PULSE DRIP IRRIGATION

ABSTRACT Eggplant is a vegetable considered as moderately sensitive to salinity, and its production is affected by water deficit in the soil, mainly in the reproductive phase of the crop. The objective of this study was to evaluate the use of irrigation with brackish water using continuous drip and pulse in production, water consumption, water use efficiency, and soil salinization. The experimental design was in randomized blocks, in a 4 × 4 factorial scheme, with five replicates, totaling 80 plots. The treatments consisted of four forms of water application, continuous drip, and pulse throughout the cycle; continuous drip in the vegetative phase and pulse in the reproductive phase, and pulse in the vegetative phase and drip in the reproductive phase and four levels of irrigation water salinity - ECw (0.3; 1.5; 3.0; 4.5 dS m−1). The inversion of irrigation treatments occurred 65 days after transplanting. Increase in water salinity from 0.3 to 4.5 dS m−1, the total production (-11.96%), fruit length (-5.05%), and water use efficiency (-7.01%) reduced while there was no significant effect for the forms of water application and interaction between the studied factors. Pulse irrigation provided greater water savings and resulted in higher electrical conductivity in the soil saturation extract. The efficiency of water use did not show statistical difference when continuous drip or pulse irrigation was used throughout the cycle. RESUMO A berinjela é uma hortaliça considerada moderadamente sensível à salinidade e sua produção é afetada pelo déficit hídrico no solo, principalmente na fase reprodutiva da cultura. Objetivou-se avaliar a influência do uso da irrigação com água salobra utilizando o gotejamento contínuo e pulsos na produção, consumo hídrico e eficiência do uso da água da berinjela e na salinização do solo. O delineamento experimental foi em blocos casualizados, arranjado em esquema fatorial 4 × 4, com cinco repetições, totalizando 80 parcelas. Os tratamentos foram compostos pela combinação de quatro formas de aplicação de água: gotejamento contínuo e pulsos durante todo o ciclo; gotejamento contínuo na fase vegetativa e por pulsos na fase reprodutiva e pulsos na fase vegetativa e gotejamento na reprodutiva; e quatro níveis de salinidade de água de irrigação - CEa (0,3; 1,5; 3,0; 4,5 dS m−1). A inversão das formas de irrigação ocorreu aos 65 dias após o transplantio. Com o aumento da salinidade da água de 0,3 a 4,5 dS m−1, a produção total (-11,96%), co