Studies on Uptake and Loss of Water by Barley Roots in Relation to Changes in Root Resistance

Publisher Website
Google Scholar
Abstract
The uptake and loss of water by roots of young barley plants have been measured using tracer techniques in sand culture under contrasting conditions of transpiration and water potential difference. The results are compared with direct potometric measurements of water uptake. The apparent resistance to flow of water changed in response to differences in water potential between the leaves and the root medium and in transpiration rate. We examine the significance of this in relation to net loss of water and possible mobilization of nutrients from dry soil. With the aid of a mathematical model, some consideration is given to the role of the endodermis as a barrier to diffusive movement of water in the older parts of the root system.