Leaf Conductance Changes on Leafy Cuttings of<i>Cornus</i>and<i>Rhododendron</i>During Propagation

Abstract

SummaryLeaf conductance was measured on Cornus and Rhododendron cuttings subjected to various rooting treatments, then transferred to a controlled environment cabinet for the duration of the measurements. The treatments which produced fastest rooting and higher leaf conductances were (i) mist plus muslin cover and (ii) a polyethylene wrap. On freshly prepared cuttings leaf conductance fell quickly, then increased as rooting progressed. The observed leaf conductance was linearly related to the length of the longest root present, but the initial stages of root formation could be seen before leaf conductance increased. Neither the propagation treatment nor the use of an antitranspirant coating effectively altered the leaf conductance of unrooted cuttings, so that cutting turgor must be determined mainly by the vapour pressure gradient between leaf and air.