Effect of Salicylic Acid and Salinity Stress on the Performance of Tomato Plants

Abstract

A pot experiment was conducted to observe the effect of salicylic acid on qualitative and quantitative attributes of tomato plants under salinity stress at Agriculture Research Institute Tarnab, Peshawar during the summer season 2016. The experiment was conducted in a shade house and laid out in a completely randomized design (CRD) having 12 treatments and replicated thrice. After 15 days of transplantation tomato plants (cv. Rio Grande) were subjected to various levels of salinity (0, 30, 60 and 90 mM) and to foliar application of salicylic acid (0, 0.5 and 1 mM) at 6 days after salinity stress. Results revealed that salinity stress (90 mM NaCl) significantly reduced the fruit length (4.71 cm), fruit diameter (3.95 cm), number of fruits plant−1 (13), yield pot−1 (0.51 kg), fruit dry matter (6.89 g), and pH (4.14) with increase in fruit firmness (2.72 kg · cm2), total soluble solids (TSS, 8.87 0Brix) and vitamin C (18.07 mg · 100 ml). The foliar application of salicylic acid at 0.5 mM significantly reduced the harmful effect of salt stress and improved the fruit length (5.02 cm), fruit diameter (4.17 cm), number of fruits plant−1 (18.67), yield pot−1 (0.86 kg), fruit dry matter (9.04 g), fruit firmness (2.68 kg · cm2), TSS (9.05 0Brix), pH (4.33) and vitamin C (17.28 mg · 100 ml). Regarding in interaction both salinity and salicylic acid significantly affected all the variables except fruit firmness, total soluble solids, pH and vitamin C. From the present study it can be concluded that salinity reduced the quantitative attributes while it increased the qualitative attributes except pH. Therefore, salicylic acid at 0.5 mM might be applied to the tomato plant under saline condition up to 90 mM which could effectively alleviates the deleterious effect of salt stress.