Salicylic acid in the induction of tolerance of guava cv. Tailandesa to controlled water deficit

Abstract

Water scarcity in semiarid regions impairs the production of fruit trees of socioeconomic importance, such as guava, requiring irrigation management strategies associated with the application of osmoregulators to provide acclimatization in plants under water stress. The objective of this study was to evaluate the potential of foliar application of salicylic acid on the physiology, vigor, quality, and phytomass of guava seedlings cv. Thailandesa grown under water stress. The experiment was conducted using a randomized block design in a 2 × 5 factorial scheme: two water conditions (50 and 100% of actual evapotranspiration – ETr) and five concentrations of salicylic acid applied via foliar (0, 1.2, 2.4, 3.6, and 4.8 mM), with four replications. Foliar application of salicylic acid at a concentration of 2.2 mM promoted a beneficial effect on the CO₂ assimilation rate under 100% ETr and mitigated the effects of water deficit of 50% ETr on gas exchange, electrolyte leakage, and chlorophyll a fluorescence of guava cv. Thailandesa.