Effect of Elevated Co2 and Shading on Growth, Physiological Changes, Yield and Quality of Cherry Tomato (Solanum Lycopersicum Var. Cerasiforme) in Tropical Climate

Abstract

Cherry tomato (Solanum lycopersicum var. cerasiforme) from family Solanaceae is an important source for vitamins and other minerals. The demand for tomatoes therefore increases due to the changes in the lifestyle of the food intake among ordinary people who are aware of their nutritional intake. Climate change is nevertheless the greatest treat that can reduced the tomato production. Cultivating indoor using greenhouse is one of the solutions to mitigate this problem. The biggest constraint in tropical climate for greenhouse cultivation, however, is solar radiation and temperature. This study was therefore intended to evaluate the growth, physiology, yield and quality of tomato under two systems of greenhouse; Smart Greenhouse (SGS) versus Conventional Greenhouse (CGS) system. Cherry tomato was grown in two greenhouses at three different shading levels of (0, 50 and 70 percent). SGS received around 800 ppm of CO₂ while CGS has been designated as control. The experiments with six replications were carried out in nested design. All the data were compared and subjected to Analysis of Variance (ANOVA). As a results, growth, physiology, and tomato yield were reduced due to high temperature inside SGS under elevated CO₂. Additionally, high temperature (32-35^oC) inhibited the assimilation of photosynthetic carbon. Thus, fruit setting was delayed thereby reducing yield production. Upon enrichment, vapor pressure deficit (VPD) decreased under elevated CO₂ and lycopene under shaded area showed 52% and 25% respectively higher compared to CGS. Overall, elevated CO₂ in tropical climate inside greenhouse influences temperature increase that have reduced growth performance, physiology, yield and quality of cherry tomato.