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Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 8/4/2008 Publication Date: 2/8/2009 Citation: Harmon, D.N., Clements, C.D. 2009. Germination Comparisons of the Crested Wheatgrass Cultivars ‘Hycrest’ and ‘Hycrest II’ [abstract]. Society for Range Management, Albuquerque, NM, February 8-12, 2009. 62:32. Interpretive Summary: Technical Abstract: With increasing threats to western rangelands, such as fire and exotic invasive plants, there is an ever-growing need for plant materials that can be successfully revegetated in these vast and important ecosystems. Wildfires are an annual event throughout the West and in the Intermountain West in particular, these wildfires often result in the conversion of native plant communities to such exotic an invasive weeds as the annual grass, cheatgrass (Bromus tectorum). Protecting or restoring these disturbed plant communities often relies on choosing the most appropriate plant materials that can establish in these often harsh and xeric environments. While native plant selections are continuously being researched, an exotic plant cultivar is often used because of the lack of success experienced with native plant materials. One such introduced plant is crested wheatgrass (Agropyron cristatum). Crested wheatgrass is native to Russia and was introduced to the United States in the early 1900s. Because of the success experienced with crested wheatgrass, thousands of acres of western rangelands have been seeded with this species in the seed mix. Crested wheatgrass also is less costly, more fire resistant, desirable forage for domestic livestock and wildlife, and above all it can establish on xeric sites and compete with such exotic and invasive weeds as cheatgrass. Since its introduction multiple cultivars have been developed. One common and widely used cultivar is ‘Hycrest’ which was developed from a hybrid of two tetraploid crested wheatgrass species and was released in 1984. Recently a new related cultivar, ‘Hycrest II’ (H2) has been developed. In the selection of these plant materials it is important to select for such traits as germination, growth form, nutrition, and site adaptability. We tested and compared the germination potential of H2 to that of ‘Hycrest’ at 55 constant and alternating temperature regimes representative of Intermountain West seedbed temperatures. Temperatures ranged from constant 0ºC to 40ºC and every possible alternating temperature regime of 8 hours warmer and 16 hours colder. For example 0ºC alternated with 2, 5, 10, 15, 20, 25, 30, 35, and 40ºC, while 35ºC only alternated with 40ºC. Initial germination was higher for H2 during the first week for alternating temperature regimes at 0ºC/15ºC, 2ºC/15ºC, 2ºC/20ºC, 5ºC/10ºC and 5ºC/15ºC. This may indicate an increased potential for H2 to germinate faster earlier in the season. Maximum germination after four weeks however did not show this pattern. We ran the complete test again to confirm these results and again H2 had lower germination over all after four weeks. These germination tests are being followed up with on the ground germination and establishment experiments to better understand and fully appreciate the need for plant materials with the inherent potential to compete successfully with such exotic and invasive weeds as cheatgrass. |
