High temperature is a major environmental stress that limits plant growth, metabolism and productivity worldwide. Plant

growth and development involve numerous biochemical reactions that are sensitive to temperature. Twenty three tomato

(Solanum Lycopersicum L.) genotypes were evaluated in the autumn-winter (main season) and spring-summer (high

temperature stress) in the field condition. Study was contemplated to compare biochemical responses and average day/night

mean temperature/humidity were 38.0°C / 23.0°C, 78% / 39% and 25.0°C / 12.0°C, 91% / 45% in spring-summer and

autumn-winter, respectively. Significant variations between genotypes were observed in both the season. It was observed

that pigments lycopene (2.6% to 62.3%), proline (0.9% to 32.3%) and titrable acidity ( 3.2% to 37.5%) concentration

enhanced during spring summer season. Chlorophyll b is highly sensitive to high temperature and thus its concentration

severely affected, and its reduction (21% to 47.9%) amongst tomato leaf in spring-summer was observed. There were not

significant differences amongst total soluble solids content were noticed in both the season. From these biochemical

observations Sel-18, EC-538156 and EC-538441 showed better performance under both the seasons.

Key Words: Autumn-winter, Lycopene, Proline, Spring-summer season, Tomato