Desiccation of bare-root tree seedlings during storage can result in reduced growth and poor quality after transplanting. For 12 weeks, shoot and root water potentials of bare-root Norway maple (Acer platanoides L.) and Washington hawthorn (Crataegus phaenopyrum Medic.) seedlings were measured in response to four cold storage treatments: whole plant exposed, roots exposed, shoots exposed, whole plant covered. In another experiment, water loss was measured from stem sections of both species during four weeks of cold storage. Shoot and root water potentials decreased during storage regardless of treatment or species. For maple, shoot and root water potentials of the exposed shoot treatment were the same as the whole plant covered treatment. In contrast, hawthorn shoot and root water potentials of the exposed shoot treatment were lower (more negative) than for the whole plant covered treatment. Most of the water stress experienced by roots and shoots of both species accumulated during the first six weeks of storage. Water loss was greater for hawthorn stem sections than for maple during the first two weeks of storage. Results indicated that while protection of roots of all bare-root stock reduces water loss, sensitive species such as Washington hawthorn require both root and shoot protection to minimize water loss.
2Graduate Assistant and Assistant Professor.
3Associate Professor, College of Forestry. VPI & SU, Blacksburg, VA 24061-0324.