Altered partitioning of new dry matter in Hedera helix (Araliaceae) induced by altered orientation
Frey D; Frick H
Bulletin of the Torrey Botanical Club
Growth of Hedera helix L \\\"Ivalace\\\" (English ivy) in either a horizontal or vertical orientation was compared over a 7 wk period of the juvenile phase. The relative growth rate (RGR) was the same for plants in either orientation while the leaf weight ratio (WL/WP) was greater in vertical plants. Shortly (2.8 wk) after vertical orientation the net assimilation rate (NAR) tended to be smaller for vertical plants but the leaf area ratio (LAR) tended to be greater. These relationships indicate that vertical plants partitioned new dry matter preferentially to increase leaf lamina area at the \\\"expense\\\" of shoot axis dry weight and obversely for horizontal plants during which time the relative growth rates remained equal.