Assessing the Impact of Higher Levels of CO(2) and Temperature and Their Interactions on Tomato (Solanum lycopersicum L.)

Climate change has increasing effects on horticultural crops. To investigate the impact of CO2 and temperature at elevated levels on tomato production and quality of fruits an experiment was conducted by growing plants in open top chambers. The tomato plants were raised at EC(550) (elevated CO(2) at 550 ppm) and EC(700) (elevated CO(2) at 700 ppm) alone and in combination with elevated temperature (ET) + 2 °C in the open top chambers. These elevate CO(2) and temperature treatment effects were compared with plants grown under ambient conditions. Outcome of the experiment indicated that growth parameters namely plant stature in terms of height (152.20 cm), leaf number (158.67), canopy spread (6127.70 cm(2)), leaf area (9110.68 cm(2)) and total dry matter (223.0 g/plant) were found to be high at EC(700) compared to plants grown at ambient conditions in open field. The plants grown at EC(700) also exhibited significantly higher number of flowers (273.80) and fruits (261.13), more fruit weight (90.46 g) and yield (5.09 kg plant(−1)) compared to plants grown at ambient conditions in open field. The percent increase in fruit yield due to EC varied from 18.37 (EC(550)) to 21.41 (EC(700)) percent respectively compared to open field and the ET by 2 °C has reduced the fruit yield by 20.01 percent. Quality traits like Total Soluble Solids (3.67 °Brix), reducing sugars (2.48%), total sugars (4.41%) and ascorbic acid (18.18 mg/100 g) were found maximum in EC(700) treated tomato than other elevated conditions. Keeping quality was also improved in tomato cultivated under EC(700) (25.60 days) than the open field (17.80 days). These findings reveal that CO(2) at 700 ppm would be a better option to improve both quantitative as well as qualitative traits in tomato. Among the combinations, EC(550) + 2 °C proved better than EC(700) + 2 °C with respect to yield as well as for the quality traits. The tomato grown under ET (+2 °C) alone recorded lowest growth and yield attributes compared to open field conditions and rest of the treatments. The positive influence of EC(700) is negated to an extent of 14.35 % when the EC(700) combined with elevated temperature of + 2 °C. The present study clearly demonstrates that the climate change in terms of increased temperature and CO(2) will have a positive effect on tomato by way of increase in production and quality of fruits. Meanwhile the increase in EC beyond 700 ppm along with ET may reduce the positive effects on yield and quality of tomato.