Role of Nutrients and Biofertilizers for Improved Tolerance of Tomato under Elevated Co2 Induced High Temperature Stress

The purpose of the study was to understand the role of different  nutrients and biofertilizers on the stress tolerance of the tomato variety Vellayani Vijai under elevated  CO2  induced  high  temperature condition. A pot culture study was done with  9 treatments included 50 ppm B + 50 ppm Zn + water spray (T1), 75 ppm B + 75 ppm Zn (T2), POP 150 ppm N + 125 ppm P+ 125 ppm K (T3), Azolla  (Soil application) (T4),  Azolla  biofertilizer  extract (20 %) (foliar application) (T5), Azolla biofertilizer extract (20%) (seed treatment) (T6), POP, KAU + PGPR1(T7), Control (water spray) (T8), Absolute control(T9). The application of 50% extra N and 25% extra P and K (T3) each than the recommended doses as per POP, KAU (Package of practices, Kerala Agricultural University) as well as foliar application of B and Zn at two different concentrations and foliar application of Azolla  biofertilizer  extract (20%) was found to be effective in inducing stress tolerance in tomato plants under elevated CO2 condition by improving the relative water content, cell membrane stability index and proline content.