A chamber for measurement of net photosynthesis on a whole plant - DOI: 10.4025/actasciagron.v29i3.469

Abstract

A limitation for quantifying photosynthesis with existing equipment is that they were designed to measure of plant parts, such as one leaf or group of few leaves, which has a great variability over the whole plant. As a consequence, it is difficult to integrate accurately the measurements taken on plant parts in order to assess the process over the entire plant. The objectives of this work were to show in detail a chamber built to measure whole plant photosynthesis and present measurements taken with this apparatus on coffee plants under field conditions. The chamber makes possible to obtain reliable measurements of CO₂ assimilation rates over canopies of different LAI and levels of light exposure. The plant with LAI equal to 1.84 had higher assimilation rates for the whole canopy, but autoshading decreased assimilation rates per leaf area unit, as compared with the plant with LAI of 0.86.