Eficiência fotoquímica e rendimento de pinhão-manso irrigado com águas salinizadas

Abstract

Jatropha (Jatropha curcas L.) is a shrubby plant belonging to the family of Euphorbiaceae, which presents a high level of savagery and hardiness, as well as having the potential to be exploited as a source of energy. This study aimed to evaluate the photochemical efficiency and yield of jatropha irrigated with saline water. The experiment was conducted under field conditions in the agricultural area belonging to the Center of Agricultural and Environmental Sciences, Campus II, State University of Paraíba, Laguna Seca, PB. In the experiment, five levels of electrical conductivity of irrigation water: (N1 = 1.20, N2 = 1.80, N3 = 2.40, N4 and N5 = 3.00 = 3.60 dS m-1, 25 º C). We adopted the experimental design in blocks, 5 treatments with 3 repetitions, totaling 15 plots. The increase in electrical conductivity of irrigation water affected significantly reducing the diameter of the fruit, photosystem II photochemical efficiency was limited by salinity from the level of 2.4 dS m -1. The variables of gas exchange (A, gs, E, C, A / E and A / Ci) were not affected by levels of electrical conductivity of irrigation water in the conditions in which they were submitted. Rising levels of electrical conductivity of irrigation water significantly reduced the production variables: number of clusters per plant, number of fruits per plant, seed weight, shell weight, number of seeds per fruit and number of fruit per cluster.