Whole Plant CO2 Exchange Measurements for Nondestructive Estimation of Growth

A computer controlled semiclosed net CO(2) exchange measurement system, employing an infrared gas analyzer and mass flow controllers to inject pure CO(2) at preset rates, has been developed for measuring whole plant net CO(2) exchange and net C gain in a controlled environment (i.e. CO(2), light, and temperature). Data for tomato (Lycoperscicon esculentum cv Campbell 19 VF) and rose (Rosa hybrida cv Samantha) plants grown for 4 and 17 day periods, respectively, clearly show that net C gain measured and computed using nondestructive CO(2) analysis equaled the increase in C content determined by chemical analysis following destruction of the test plants. The analysis of C gain based on CO(2) exchange allows estimation of biomass production and growth of a single population of plants under varying light and CO(2) conditions without physically handling the test plants.