Quantum yield, chlorophyll, and cell damage in yellow passion fruit under irrigation strategies with brackish water and potassium

Abstract

The occurrence of water sources with high concentrations of salts in the semiarid region of Northeast Brazil stands out as a limiting factor in the cultivation of irrigated yellow passion fruit. Thus the search for irrigation strategies with brackish water is fundamental for the sustainability of irrigated crops. The objective of the present study was to determine the quantum yield, chlorophyll levels, and cell damage in yellow passion fruit cultivated under different irrigation strategies with brackish water and potassium fertilization. The experiment was conducted under field conditions in São Domingos -PB, Brazil, adopting a randomized block design in a 6×2 factorial scheme, consisting of six strategies of use of brackish water applied in the different phenological stages of crop and two doses of potassium (60 and 100% of the recommendation), with four replicates. Two levels of irrigation water salinity were used, with low (1.3 dS m -1 ) and high electrical conductivity (4.0 dS m -1 ). The potassium dose of 100% recommendation corresponds to the application of 345 g of K 2 O per plant per year. The use of brackish water (4.0 dS m -1 ) increased chlorophyll fluorescence and negatively affected the photosynthetic pigments of yellow passion fruit, regardless of the phenological stage. Salt stress intensified intercellular electrolyte leakage in passion fruit plants under higher dose of potassium. Our results show that fertilization equivalent to 100% of the potassium recommendation is excessive for yellow passion fruit 'BRS GA1' in the tropical semiarid region under salt stress conditions.

Physiology and production of sugar-apple under water stress and application of proline

“…Obstacles to the expansion of production areas in the Brazilian semi-arid region include rainfall irregularity and high evapotranspiration rate, which results in limitations to adequate water availability during the crop cycle, leading to production losses and changes in fruit quality (Lima et al, 2015;Capitulino et al, 2022;Pinheiro et al, 2022a). The sugar-apple is tolerant to conditions of water deficiency (Fernandes et al, 2022), however, the sensitivity of plants to stress varies according to the stages of development (Ferreira et al, 2022).…”

Salicylic acid concentrations and forms of application mitigate water stress in sour passion fruit seedlings

“…In this scenario, the effects of water stress on each crop may vary depending on the management of irrigation and fertilization, edaphoclimatic conditions, species, or even the different developmental stages (Deka et al, 2018), manifesting more intensely during early development through metabolic and physiological changes and resulting in growth inhibition (Morales et al, 2020;Zombardo et al, 2020). As already observed in passion fruit, the photosynthetic rate decreases through stomatal closure due to the lower CO 2 entry and electron transport limitations in the PSII, resulting in lower carbon fixation and forming reactive oxygen species (ROS), which affect the metabolic activity of the plant (Pinheiro et al, 2022b;Souza et al, 2018;Cavalcante et al, 2020;Lozano-Montaña et al, 2021).…”