Note on the temperatures of leaf and meristematic tissue of plants of short-rotation ryegrass in summer conditions

Abstract

Fine thermocouples were used to compare. under various environmental conditions, the temperature of the leaf blade, and the meristem at the base of the tiller with the temperature of the air and of the soil surface. Under both low and high intensities of solar radiation, the temperature of the leaf blades remained close to the temperature of the air adjacent. If a tiller and the soil surrounding it were exposed to high-intensity solar radiation, the temperature of the meristematic zone at the base of the tiller rose 10°F or more above the temperature of the air 1 ft above it. However, where a plant had a tussock habit of growth, and hence the tiller meristems were sheltered from radiation, there was little difference between the temperatures of the air, the tiller meristem, and the adjacent soil surface.