Desempenho agronômico do maracujazeiro-amarelo sob irrigação com águas de diferentes naturezas catiônicas.

Abstract

In the Brazilian semiarid region, water resources, in general, have high levels of salts, in addition, they are characterized by varying their composition, with the occurrence of high amounts of chloride and sodium in dilution, which can compromise crop yield. In this context, this study aimed to evaluate the growth, physiology and production of yellow passion fruit 'BRS Rubi Cerrado', cultivated with waters of different cationic nature in a protected environment. For this, the experiment took placein drainage lysimeters, in a greenhouse belonging to the 14Academic Unit of Agricultural Engineering at the Federal University of Campina Grande, Campina Grande-PB, from March 2019 to January 2020. A randomized block design was used, being a control treatment (supply water) and seven different cationic natures (S1 -Control; S2 - Na+; S3 - Ca2+; S4 - Mg2+; S5 - Na+ + Ca2+ ; S6 - Na+ + Mg2+; S7 - Ca2+ Mg2+and S8 - Na+ + Ca2+ Mg2+) and three replicates, totaling 24 experimental plots. The control treatment had low electrical conductivity - ECw (0.4 dS m-1), and the other treatments contained 3.5 dS m-1 CEa prepared with different cations. The growth of the yellow passion fruit is affected by the variation in the level of the electrical conductivity of the water, regardless of the cationic nature of the irrigation water. A 180 days after transplanting, the use of sodium saline water favored an increase in the synthesis of chlorophyll a, b and carotenoids in yellow passion fruit plants. In addition, the different cationic nature of irrigation water did not influence the fluorescence variables of the yellow passion fruit. Increasing salinity of the water reduces iu gas exchange, especially, stomatal conductance and transpiration in plants passion fruit -yellow 180 days after transplanting. Gas exchange was affected by the variation of the cationic nature, with the greatest reductions when the plants were irrigated with saline water with Mg2+. The number of yellow passion fruit fruits 'BRS Rubi do Cerrado' was affected by the increase in the electrical conductivity of irrigation water. The ion Ca2+ turn promotes u major deleterious effects in the production variables in plant passion fruit, to 259 days after transplanting.