Suppression of Tillering in Erianthus ravennae (L.) Beauv. Due to Drought Stress at Establishment

摘要

We investigated the effect of drought stress on biomass productivity of newly established Erianthus ravennae (L.) Beauv. This species has recently drawn great attention as a novel cellulosic energy crop because of its excellent tolerance against various environmental stresses, but the shoot dry weight of the newly established E. ravennae was significantly decreased under drought compared to irrigated condition. A significant correlation between shoot dry weight and stem number suggested that the drought-induced decrease in stem number was ascribable to the reduced shoot dry weight in the drought condition. Decrease in soil water content was coincident with mid-day decrease in stomatal conductance, suggesting that limitation of CO2 diffusion into leaf due to lower stomatal conductance in the drought condition caused decrease in photosynthesis followed by suppression of stem number. The present study suggested that E. ravennae was susceptible to drought, at least, in the first establishment year.