Effect of Drought and Phenological Stage at Transplanting on Root Hydraulic Conductivity, Growth Indices, and Photosynthesis of Turkish Hazelnut

Abstract

A single drought episode was applied to two groups of container-grown Corylus colurna L. (Turkish hazelnut) seedlings which had concomitantly reached distinct phenological stages; 1) buds opening and no new root growth visible and 2) shoot extension well underway and new root growth just beginning. Two days after rewetting, root hydraulic conductivity was lower for plants exposed to drought, but there was no phenological stage effect. No differences in root hydraulic conductivity were apparent among well-watered plants of stage 1, 2 and a third stage, 3) shoot extension complete (buds set) and root growth well underway. Twenty five days after return to daily irrigation, those plants subjected to the drying treatment had smaller diameter trunks, but total plant height and dry weight of root-balls were similar. No differences in photosynthetic rate or stomatal conductance were evident 25 days after transplanting.