Postharvest Quality of Sour Passion Fruit Under Irrigation Strategies with Brackish Water and Potassium Application in Two Crop Cycles

The objective of this study was to evaluate the physicochemical quality of fruits of "BRS GA1" sour passion fruit cultivated under different irrigation strategies with brackish water and potassium (K) fertilization in two production cycles. The experiment was conducted under field conditions in Sao Domingos-PB, Brazil, using a randomized block design in a 6 x 2 factorial scheme, with six strategies of irrigation with brackish water applied in different phenological stages: WS, irrigation with water of low electrical conductivity (ECw) throughout the cycle; irrigation with water of high ECw in the vegetative stage (VE); flowering stage (FL); fruiting stage (FR); in the successive vegetative and flowering stages (VE/FL); and vegetative and fruiting stages (VE/FR) and two doses of K (60 and 100% of the recommendation), with four replicates and three plants per plot. Water with two levels of ECw (1.3 and 4.0 dS m(-1)) was used. The K dose of 100% corresponded to 345 g of K2O per plant per year. Salt stress in the vegetative/fruiting and fruiting stages does not affect the polar and equatorial diameters of the "BRS GA1" sour passion fruit. K dose of 60% increased the polar diameter of sour passion fruit and, when associated with salt stress in the vegetative, flowering, fruiting, and vegetative/fruiting stages, increased the ascorbic acid contents. Irrigation with water of 4.0 dS m(-1) in the vegetative/flowering stage and fertilization with 100% K dose increased the total titratable acidity and reduced the hydrogen potential, and soluble solids content of the pulp of "BRS GA1" sour passion fruit, regardless of the phenological stage.