Growth reactions of carnation, measured by net photosynthesis, on different air contents of the soil.

Abstract

In pot experiments, Dianthus caryophyllus plants grown for 2 1/2 months at soil-air levels of 20, 10 or 5% (v/v) produced approx. equal amounts of dry matter, but fresh-matter production at 5 and 10% soil air was 13 and 2% lower than at 20% soil air. The effect of aeration on growth (photosynthesis) increased with increasing light intensity. Decreasing content of soil air from 20, 10 and 5% to 5 and 2.5% respectively was accompanied by an immediate reduction of photosynthesis to a fairly constant level. This reduction increased with increasing light intensity. An increase in soil air from 2.5 to 20, 10 or 5% gave a recovery of photosynthesis which at the two lowest light intensities was complete within 1-3 days when the period of low air content was not >14 days. At the highest light intensity the recovery of photosynthesis was slower. (Abstract retrieved from CAB Abstracts by CABI’s permission)