GROWTH, BIOMASS ALLOCATION, AND PHENOLOGY RESPONSES OF PEPPER TO ELEVATED CO2 CONCENTRATIONS AND DIFFERENT WATER AND NITROGEN SUPPLY

Fifty-day old plants of Capsicum annuum L. with two developed leaves w ere placed into controlled environment chambers at atmospheric (350 cm (3) m(-3), ACO(2)) and elevated (700 cm(3) m(-3), ECO(2)) CO2 concentr ations under different nitrogen and water supply. Plant response to EC O(2) and the modulating effect of the availability of nitrogen and wat er were evaluated. CO2 effects were significant only after 40 d of tre atment. An increase in plant growth and yield was found in ECO(2) plan ts only under a good supply of both water (HW) and nitrogen (HN). Chlo rophyll concentration responded only to N supply. Root/shoot ratio was higher under ECO(2) only under low N (LN) and low water (LW) supply. Leaf area and specific leaf area decreased under ECO2. Flowering and f ructification took place earlier in ECO(2) under HN and HW. Thus, all CO2 effects were modulated by the N and water supply and the duration of exposure.