Postharvest Quality of Noble and Nordmann Fir Christmas Trees

Abstract

Moisture and needle loss characteristics were similar for noble (Abies procera Red.) and Nordmann fir [Abies nordmanniana (Stev.) Spach.] Christmas trees that were displayed in water. After 42 days, trees still had xylem pressure potentials above -2 MPa. In addition, trees that were displayed in water had very little needle loss. When trees were displayed dry, noble and Nordmann fir had similar rates of moisture loss, drying to about -6 MPa in about 3 weeks. Although there was very little needle loss from any of the noble fir trees that were displayed dry, some Nordmann fir trees began to shed large numbers of green needles within 3 to 5 days, which significantly reduced postharvest quality. Unless sources of Nordmann fir are identified that have good needle retention characteristics, the needle loss problem observed when trees dry to about -3 MPa has the potential to limit the use of this species as a Christmas tree in the United States.