Free-energy transfer in plants.

Free-energy transfer was used to study water transport through the soil-plant system. Resistances to free-energy transfer are proportional to resistances to water transfer. Under certain conditions, the proportionality factor is 1. For a sunflower plant in moist soil, plant resistance to free-energy transfer was 30 times the soil resistance, and root-stem-leaf resistances were in a ratio of about 2 : 1 : 1, respectively. However, root and sidered for a unit pathlength.