Effect of Transplanting on Shoot Water Potential of Bareroot Washington Hawthorn and Norway Maple Trees

Abstract

Abstract Two-year-old Norway maple (Acer platanoides L.) and Washington hawthorn (Crataegus phaenopyrum Med.) trees were cold-stored for 2, 4, 6, 8, 10, and 12 weeks and stem water potentials were measured prior to and five days after transplanting. In a second experiment, a wax coating was applied to hawthorn trees at transplanting and shoot water potential was measured at two-day intervals for twelve days after transplanting; percent bud break was measured eight weeks after transplanting. In a third experiment, maple and hawthorn trees were stored for 2, 4, 6, 8, 10, and 12 weeks with the following tree covering treatments: whole plant covered, shoots exposed, roots exposed, and whole plant exposed, and root hydraulic conductivity was measured for each storage duration. For each storage duration, maple stem water potentials after transplanting were the same as or higher than the pre-transplant potential value; hawthorn water potentials after transplanting were generally lower than pre-transplant values. Six to eight days after transplanting, hawthorn water potentials of wax covered stems were higher than unwaxed stems. Bud break percentages were higher for trees with waxed stems than for trees without wax. Root hydraulic conductivity was the same for both species and decreased with increased storage duration and for treatments exposing roots.