Carbon dioxide elevation combined with sufficient irrigation and nitrogen fertilization improves fruit quality of tomato grown in glasshouse

Abstract

ABSTRACT To investigate the interactive effects of elevated CO2 (e[CO2]), nitrogen (N) supply and irrigation regimes on tomato (Solanum lycopersicum L., cv. Elin) yield, water use efficiency (WUE) and fruit quality, potted plants were grown in glasshouse compartments with CO2 concentration of 400 and 800 ppm, separately, with 0 or 0.5 g N kg−1 soil. Since anthesis, the plants were subjected to three irrigation levels (I1, I2 and I3 – irrigated to 35% soil water content (SWC, v/v), 30% SWC and 25% SWC, respectively). e[CO2] had a slight effect on fruit yield and sugar, acid, soluble solids content (SSC) and total antioxidant capacity (TAC) in fruit juice, while it enhanced Mn, B and Fe contents in fruit biomass. WUE was improved by e[CO2] and I3 irrigation, but reduced by N supply. Though N supply lowered SSC, TAC, K+, Ca2+ and Mg2+ in fruit juice, it increased micro-nutrient (Mn, Mo, Cu, Zn, Fe) contents in fruit biomass. Most notably, principal component analysis revealed the best comprehensive quality of tomato fruits was found for plants grown under e[CO2] with sufficient irrigation and N supply, suggesting optimal irrigation and N fertilization are essential for good tomato quality in glasshouse production under CO2-enriched environment.