Production, dry matter (including reproductive) allocation, photosynthesis, transpiration, water use efficiency and carbon and nitrogen responses of a Hungarian sweet pepper (Capsicum annum L.) under continuous elevated CO 2 concentrations are reported. Plants were grown in open top chambers under a temperate-continental climate in Hungary from plantation at ambient (350 µmol mol Ϫ1 ) and elevatedLajos Helyes is affiliated with the ABBREVIATIONS. A = CO 2 assimilation rate; Ca = ambient CO 2 concentration; Ci = intercellular CO 2 concentration; dm = dry mass; E = transpiration rate; gs = stomatal conductance; RA = reproductive allocation; Rubisco = RuBP carboxylase/oxygenase; WUE = water use efficiency