GAS EXCHANGE AND PRODUCTION OF PASSION FRUIT AS AFFECTED BY CATIONIC NATURE OF IRRIGATION WATER1

ABSTRACT Yellow passion fruit is a species widely cultivated throughout the Brazilian semi-arid territory, but its yield affected by quality of waters this region. In context, objective was to evaluate gas exchange and production cv. BRS Rubi do Cerrado irrigated with different cationic natures. The study conducted in drainage lysimeters under greenhouse conditions Campina Grande, PB, Brazil, randomized block design, treatments were eight natures irrigation water (S1 - Control; S2 Na+; S3 Ca2+; S4 Mg2+; S5 Na+ + S6 S7 Ca2+ Mg2+ S8 Mg2+) three replicates. Plants control treatment low electrical conductivity (ECw = 0.4 dS m-1), while those other using ECw 3.5 m-1. Ca2+, prepared equivalent ratio 1:1, Na++Ca2++Mg2+ 7:2:1, respectively. Water salinity m-1 reduced exchange, stomatal conductance transpiration most sensitive variables fruit. number fruits decreased salinity, regardless nature. calcic calcic+magnesian nature caused greatest deleterious effects on fruit, at 259 days after transplanting.