Phenolic Compounds Enhanced Low Temperature Stress Tolerance in Tomato (Solanum lycopersicum L.)

Low temperature stress adversely affects plant growth and development and it directly affects the yield and quality of tomato. Phenolic compounds have been implicated to mitigate cold stress. Therefore an experiment was conducted to find out suitable concentration of phenolic compounds to ameliorate effect of low temperature stress in tomato under open field conditions during winter season of 2014-15 and 2015-16. The average minimum temperatures were below 10°C from December 15 to February 15 for both the years of study. The experimental plants were given foliar application twice, first 15 days after transplanting followed by another spray after a fortnight of phenolic compounds viz., salicylic acid, sulfo salicylic acid, benzoic acid, methyl salicylic acid and acetyl salicylic acid at different concentration, i.e., 0.1 mM, 0.5 mM & 1.0 mM in order to evaluate their effect on morphological, yield and quality traits. Based on two year study, its observed that low temperature significantly reduces the growth traits (plant height, number of branches, number of leaves, shoot and root length, and total biomass of plant), yield attributes (days to 50% flowering, fruit weight and fruit yield) and quality parameter (total soluble solid), however there was an increase in titrable acidity and ascorbic acid. On the hand, application of phenolic compounds significantly enhanced the growth, yield and TSS, while, decreased titrable acidity and ascorbic acid under stress. Two years study has confirmed that phenolic compounds protect plants against low temperature stress and enhanced production of tomato with an increase in the yield and quality contributions attributes. Among the treatments, SA (1.0 mM) was found as most effective to enhance low temperature stress tolerance in tomato.