EXOGENOUS APPLICATION OF SALICYLIC ACID IMPROVES PHYSIOCHEMICAL AND QUALITY TRAITS OF TOMATO (SOLANUM LYCOPERSICUM L.) UNDER ELEVATED TEMPERATURE STRESS

Globally temperature is increasing continuously due to climate change and anthropogenic activities. This rampant increase in temperature disturbs certain plant metabolic functions and retards plant growth. Tomato (Solanum lycopersicum L.) is highly economical but heat prune crops that hamper growth at high temperatures. Salicylic acid (SA) is a plant hormone used to mitigate environmental stresses but its role against high temperatures is largely unknown. Therefore, this study was aimed to investigate the impact of SA (0.0 mM, 0.25 mM, 0.75 mM, and 1.25 mM) exogenous foliar applications on tomato crops under elevated temperatures at 30 days (35 +/- 2 degrees C), 60 days (40 +/- 2 degrees C), and 90 days interval (45 +/- 2 degrees C). The results revealed that SA application was quite effective in enhancing tomato morphological traits including number of leaves, flowers, plant height, and stem diameter, and SA 0.25 mM concentration was highly efficient among other treatments. Likewise, in plant physiological traits, the highest leaf relative water contents (0.04%), photosynthesis rate (4.80 mu mol m(-2)s(-1)), vapor pressure deficient (14.44 kPa), and lowest stomatal conductance (326.86 gs, mol m(-2)s(-1)) and transpiration rate (326.86 mol m(2)s(-1)) were also observed at a similar concentration. The application of SA on tomato crops under high elevated temperatures ameliorated its quality attributes like total soluble solids, titratable acidity, and ascorbic acid contents.