Impact of Salicylic Acid Foliar Application on Growth, Nutrient Uptake, and Physiological Responses of Pepper Plants under Deficit Irrigation


GÜLÜT K. Y., TAZE G.

ISPEC journal of agricultural sciences (Online), vol.8, no.2, pp.310-327, 2024 (Peer-Reviewed Journal) identifier

Abstract

This study examines the impact of foliar application of salicylic acid (SA) at various concentrations on the growth, nutrient uptake, and physiological responses of pepper plants (Capsicum annuum L.) subjected to different levels of deficit irrigation. Pepper plants were exposed to three irrigation regimes (full irrigation, 75% field capacity, and 50% field capacity) and four SA concentrations (0 mM, 0.25 mM, 0.50 mM, and 1.0 mM). Decreasing irrigation levels led to significant reductions in fresh shoot weight, dry shoot weight, root dry weight, and plant height, with reductions of up to 66% observed under severe drought conditions. However, foliar application of SA mitigated these reductions, with an 18% increase in fresh shoot weight and up to 50% increase in root dry weight observed at the highest SA concentration (1.0 mM). Analysis of nutrient contents in fresh shoots revealed higher concentrations of several macro and micronutrients under reduced irrigation levels, attributed to the dilution effect. SA application positively correlated with increased uptake of essential nutrients, particularly potassium, magnesium, and calcium. Chlorophyll and carotenoid contents remained unaffected by SA application or irrigation levels. Relative water content varied across SA treatments and irrigation levels, indicating potential alterations in water status. Electrical conductivity measurements showed variability among treatments, suggesting changes in membrane permeability. Overall, our findings underscore the potential of SA foliar application to mitigate the adverse effects of deficit irrigation on pepper plant growth and nutrient uptake, offering insights for enhancing plant productivity and resilience to drought stress in arid and semi-arid regions.