MITIGATION OF SALT STRESS IN TOMATO BY FOLIAR APPLICATION OF POTASSIUM NITRATE

Abstract

A pot experiment was conducted at the Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka-1207, during the period from October 2019 to March 2020 to find out the effect of salinity levels and potassium nitrate on morphological, yield and yield contributing characters of tomato. The materials used for the experiment were BARI Tomato 19. In this experiment, the treatments consisted of five different salinity levels viz,, L 0 = 0 dSm -1 (Control), L 1 = 2 dSm , L 3 = 6 dSm -1 and L 4 = 8 dSm -1 -1 , L 2 and three different levels of potassium nitrate viz., M 0 = 0 mM (Control), M 1 = 5 mM, M 2 = 10 mM. The experiment was setup in a two factor Randomized Complete Block Design (RCBD) with three replications. Data were taken from plant height, number of leaves plant -1 , number of branches plant , days to first flowering, number of flower cluster -1 , number of flower cluster plant , number of flowers plant -1 , number of dropped flower plant -1 , number of fruit plant , fruit length, fruit diameter, dry matter content of fruit, individual fruit weight, fruit weight plant . When single effect was considered, salinity adversely affected most of the growth and yield parameters, but application of potassium nitrate elevated all the mentioned parameters. When combined effect was considered, the maximum plant height (121.4 cm), number of branches plant -1 (8.13), leaves plant -1 (39.33), minimum days to first flowering (38.33 days), cluster plant -1 (8.92), flower cluster -1 -1 -1 = 4 dSm -1 (8.67), flower plant

(77.34), fruit plant -1 (53.67), the highest individual fruit weight (69.11 g) and fruit yield plant -1 (3.71 kg) were found from L 0 M 2 (10 mM KNO 3 with no salinity stress condition), whereas the opposite value was obtained from L 4 M 0 (8 dSm NaCl with no KNO 3 condition) treatment combination. The experimental results showed that different levels of salinity significantly affect the morphological characters and yield of tomato. Exogenous application of potassium nitrate significantly increased the morphological characters, yield contributing characters and yield of tomato in both saline and non-saline conditions. Among the different concentration of potassium nitrate, tomato showed better response with 10 mM concentration of potassium nitrate.