The Chilling Optimum of Idaho and Arizona Ponderosa Pine Buds
- Author(s): Wenny, David L.; Swanson, Daniel J.; Dumroese, R. Kasten
- Date: 2002
- Source: West J. Appl. For. 17(3):117-121 2002.
- Station ID: --
Ponderosa pine (Pinus ponderosa) seedlings from Idaho (var. ponderosa) and Arizona (var. scopulorum) grown in a container nursery received optimum chilling [2,010 hr (84 days) of temperatures below 5°C]. While seedlings were in the greenhouse, days required for 50% of the population to break bud were similar for both seed sources and decreased inverse exponentially from 74 to 23 days as chilling hours accumulated to the optimum. When subsequently placed into either refrigerated or frozen storage, Idaho seedlings broke bud significantly faster than Arizona seedlings when returned to favorable environmental conditions for growth. All seedlings removed from refrigerated storage broke bud faster, were less cold tolerant, and therefore less quiescent than seedlings that had been frozen.
You can order print copies of our publications through our Publication Ordering System. Make a note of the publication you wish to request, and visit our Publication Order Site.
- We recommend that you print this page and attach it to the printout of the article to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
- Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS Webmaster if you notice any errors which make this publication unuseable.
- To view this article get the latest version of the Adobe Acrobat Reader.