Net photosynthesis and co2 compensation concentration in three coffee (coffea sp.) genotypes, bean and maize under three temperaturas.

Abstract

The coffee (Coffea arabica L.) genotypes Colombia, Caturra, and Híbrido de Timor, and bean (Phaseolus vulgaris L.) and maize (Zea mays L.) plants were exposed to three temperatures (15°C, 25°C and 35°C), and net photosynthetic rates (PN) and CO2 compensation concentrations (CO2) were measured. PN in coffee leaves was similar for the three genotypes at 15 °C [5,0 . 5,3 µmol(CO2) m-2s-1] and 35 °C [4,9 . 5,5 µmol(CO2) m-2s-1], but lower at 25 °C [5,4 . 11,7 µmol(CO2) m-2s-1]. CO2 increased with temperature in coffee and bean, while in maize no effect was observed. PN and CO2 values documented in coffee genotypes were typical for C3 plants.