Woody plant evaluation in Colorado
Date
2011
Authors
MacDonald, Robert Jon, author
Klett, James E., advisor
Jacobi, William R., committee member
Rogoyski, Matthew K., committee member
Journal Title
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Volume Title
Abstract
Part 1: Evaluation of cold hardiness of Cupressus arizonica 'Cooke Peak'. A trial was conducted to assess the cold hardiness of twig and foliage samples of Cupressus arizonica 'Cooke Peak', trees grown from seed with a high elevation provenance. Samples were collected monthly over a three month period, November, December, and January, during the winter of 2005-2006 from three Colorado field sites. Individual samples were dissected into four subsets, and chilled to three target temperatures in an artificial freezing chamber at Colorado State University, Fort Collins, Colorado. Each month`s samples were prepared and chilled within one week of collection. One subset was held as a control, while the others were chilled to -10 °C, -20 °C, and -30 °C. One set of subsamples was removed from the freezing chamber at each of the three target temperatures. Samples were held at room temperature for one week to allow visual damage to develop. Two evaluators assessed visual damage symptoms in the cambium and on the foliage and assigned scores based on the percent of damage. Results indicate that this tree is hardy to -20 °C, with visual damage increasing as temperatures approach -30 °C. Part 2: Multi-site woody plant evaluation in Colorado. A multi-site evaluation of five woody plant taxa was conducted at five sites in Colorado with differing soil and weather conditions and cultural management practices. This project is a partnership with Plant Select®, a Colorado non-profit corporation that makes plant recommendations and introductions. Data was collected for five years, 2002-2006, beginning at planting. Plants were evaluated based on rates of survival, and increases in caliper, canopy width, and height. Information regarding ornamental features and pest infestations was also recorded to assist Plant Select® in determining if plants warranted introduction or recommendation for widespread use in the State. Plants included in the trial were Cotoneaster ignavus 'Szechuan Fire,' Cupressus arizonica 'Cooke Peak,' Fraxinus Americana 'Jeffnor,' Fraxinus x 'Northern Gem,' and Tilia mongolica x Tilia cordata 'Harvest Gold.' Statistical analyses of growth measures showed significant differences between plants of the same taxon at different sites. While all plants adapted to Colorado growing condition, researchers felt that only Tilia mongolica x Tilia cordata 'Harvest Gold' should be recommended for widespread use.
Description
Rights Access
Subject
cold hardiness
woody plant evaluation
Cupressus arizonica 'Cooke Peak'