The Influence of Collection Time and Storage Temperature on Populus Hardwood Cutting Development

Abstract

Hybrid poplar plantations in the northern Lake States are commonly established from dormant cuttings collected in midwinter and stored in unheated shelters or cold rooms for several months until spring. However, little is known about the effects of collection time or storage temperature on cutting performance after planting. Studies by Farmer (1) with cottonwood (Populus deltoides Marsh.) and Gemperle (2) with white poplar (Populus alba L.) showed that rooting performance was better for cuttings taken in late winter than for those collected in early winter. Smith and Wareing (3) found bud development and rooting of dormant cuttings of Populus x 'Robusta' Schneid. were significantly affected by certain constant or variable temperature regimes. We tested cuttings from four hybrid poplar clones to assess the importance of collection time and storage temperature on root and bud development after planting. We also tested them to determine whether chilling requirements of fallcollected cuttings could be satisfied by certain cold storage temperatures.