Estratégias de irrigação com déficit hídrico e aplicação foliar de ácido ascórbico no cultivo de maracujazeiro azedo.

Abstract

The prolonged periods of drought occurring in the Brazilian semi-arid region have hampered the expansion of sour passion fruit cultivation, making it necessary to adopt strategies aimed at mitigating the effects of water deficit, which starts from identifying the susceptibility of the phenological phases, to the application of elictors, such as ascorbic acid. In this context, the objective of this study was to evaluate the physiology, mineral nutrition, production and quality of yellow passion fruit cv. BRS GA1 depending on the management strategies of deficient irrigation and foliar application of ascorbic acid in semi-arid conditions in Paraíba. The study was conducted under field conditions, in a randomized block design in a split-plot scheme, with the plots consisting of six irrigation management strategies with water deficit, based on crop evapotranspiration - ETc (irrigation depth equivalent to 100% of ETc throughout the cultivation cycle – S1; irrigation with 50% of ETc in the different phases: vegetative – S2; flowering – S3; fruiting – S4; in the successive vegetative/flowering phases – S5; and vegetative/fruiting – S6) and three AsA concentrations (0, 0.5 and 1.0 mM), with three replications and three plants per plot. The condition of water deficit in irrigation strategies, in general, led to changes in the photosynthetic activity of passion fruit plants, with losses in production and foliar nutrient content. The loss of productivity in the water deficit condition is greater than the changes observed in gas exchange, with fluorescence and pigment content being little affected by the stress condition. The sour passion fruit cv. BRS GA1 is sensitive to water deficit in the flowering phase, causing damage to the production and post-harvest quality of sour passion fruit fruits. AsA, in both concentrations, contributed positively to the photosynthetic activity, nutrition, production and post-harvest quality of sour passion fruit fruits, being effective in alleviating water deficit at 220 days after transplanting (DAT).