Daily measurement of CO2 assimilation rate on a kiwifruit vine

Abstract

CO2 assimilation rate of a ‘Hayward’ kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson) adult vine was measured during the summer of 1989 by two methods. One, an open-system chamber enclosing a whole vine canopy, was designed for continuous investigation of photosynthesis via the monitoring of external light, humidity, air flow, and air CO2 concentration. The other was the ADC-LCA1 system, which sampled only a part of a single leaf. The results indicate that photosynthesis rate value increases with light intensity in both instances, but, with respect to the single-leaf C02 measurements, the whole canopy CO2 exchange measurement shows lower variability. Also absolute values for single leaf photosynthesis are higher than those observed for the whole plant. © 1994 The Royal Society of New Zealand.