Impact of Elevated CO₂ and Temperature on Growth, Development and Nutrient Uptake of Tomato

Elevated carbon dioxide (EC) can increase the growth and development of different C₃ fruit crops, which may further increase the nutrient demand by the accumulated biomass. In this context, the current investigation was conceptualized to evaluate the growth performance and nutrient uptake by tomato plants under elevated CO₂ (EC₇₀₀ and EC₅₅₀ ppm) and temperature (+2 °C) in comparison to ambient conditions. Significant improvement in the growth indicating parameters like leaf area, leaf area index, leaf area duration and crop growth rate were measured at EC₇₀₀ and EC₅₅₀ at different stages of crop growth. Further, broader and thicker leaves of plants under EC₇₀₀ and EC₅₅₀ have intercepted higher radiation by almost 11% more than open field plants. Conversely, elevated temperature (+2 °C) had negative influence on crop growth and intercepted almost 7% lower radiation over plants under ambient conditions. Interestingly, earliness of phenophases viz., branch initiation (3.0 days), flower initiation (4.14 days), fruit initiation (4.07 days) and fruit maturation (7.60 days) were observed at EC₇₀₀ + 2 °C, but it was statistically on par with EC₇₀₀ and EC₅₅₀ + 2 °C. Irrespective of the plant parts and growth stages, plants under EC₇₀₀ and EC₅₅₀ have showed significantly higher nutrient uptake due to higher root biomass. At EC₇₀₀, the tune of increase in total nitrogen, phosphorus and potassium uptake was almost 134%, 126% and 135%, respectively compared to open field crop. This indicates higher nutrient demand by the crop under elevated CO₂ levels because of higher dry matter accumulation and radiation interception. Thus, nutrient application is needed to be monitored at different growth stages as per the crop needs.