AN EVALUATION OF THE ROLE OF DIURNAL TEMPERATURES IN THE HARDENING OF BARE ROOT WHITE SPRUCE SEEDLINGS

Autor: Daly, E. J., Hoddinott, J.
Jazyk: angličtina
Rok vydání: 1990
Předmět:
Zdroj: BIOTRONICS. 19:61-70
ISSN: 0289-0011
Popis: Bare root seedlings are often lifted and placed in cold storage for overwintering. It is critical that lifting occur when the seedlings are best able to survive the stresses of storage and spring outplanting. To predict the optimal lifting time for white spruce (Picea glauca (Voss) Moench) seedlings, field grown seedlings were placed in growth chambers and exposed to a range of diurnal thermoperiods in short day illumination conditions. Seedlings were then cold stressed at a range of temperatures down to -35℃ and survival was estimated on the basis of TTC reduction tests and visual observation of regrowth. Pre-stress exposure to a range of thermoperiods showed that seedlings survived well when stressed to -15℃. The best survival occurred when they had been subjected to day temperatures of 6 and night temperatures of -5℃ which enhanced their ability to withstand cold stress down to -25℃.
Databáze: OpenAIRE