VEGETATIVE MATURITY OF Amelanchier alnifolia Nutt. COMPARED TO RED-OSIER DOGWOOD AND RESCUE CRABAPPLE

Abstract

Onset of vegetative maturity and its relationship to cold acclimation was studied in the saskatoon berry (Amelanchier alnifolia Nutt.). Red-osier dogwood (Cornus stolonifera Michx.) and Rescue crabapple (Malus domestica × baccata) were also included in the study for comparison. The onset of vegetative maturity was on 29 May 1985. This was 2 mo earlier than the onset of vegetative maturity in dogwood or Rescue crabapple. Shoots of saskatoon berry subjected to cool temperatures (4 °C) for a 2-wk interval after the onset of vegetative maturity induced cold acclimation from −10 °C to −25 °C, whereas shoots collected prior to the date of vegetative maturity were unable to acclimate. Daylength had no effect on cold acclimation.Key words: Amelanchier alnifolia, dogwood, crabapple, cold acclimation, frost hardiness, saskatoon berry