Location: Forage and Range ResearchTitle: Phenotypic performance of timothy accessions under irrigated and non-irrigated conditions Author
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2013
Publication Date: 4/9/2014
Citation: Robins, J.G., Escribano, S. 2014. Phenotypic performance of timothy accessions under irrigated and non-irrigated conditions. Crop Science. 54:1079-1086. Interpretive Summary: We conducted an evaluation of 112 unimproved timothy lines and 6 commercial varieties under irrigated and non-irrigated conditions. The evaluation included forage yield and forage quality, including the measurement of water-soluble carbohydrate concentrations in the forage. We identified substantial differences for forage yield and forage quality among the included lines under both irrigated and non-irrigated conditions. The commercial varieties possessed little benefit over the unimproved lines for the measured traits. Thus, the unimproved lines can be used to improve timothy productivity for the hay production in the Intermountain Region.
Technical Abstract: Timothy (Phleum pratense L.) is one of the most winter hardy cool-season perennial grasses, used for forage production. However, its lack of tolerance to water stress requires supplemental irrigation for successful production in more arid areas of the world. A set of 112 timothy accessions and six check cultivars were evaluated for dry matter yield, in vitro true digestibility, neutral detergent fiber, crude protein and water soluble carbohydrates across two production years at Lewiston, UT, and Tetonia, ID. Supplemental irrigation was not supplied at Tetonia. For each of the traits but water-soluble carbohydrates, the variance due to the main effect of accessions differed from zero. There was also accession x environment interaction for each of the traits. Within environment broad-sense heritability estimate differed from zero and ranged from 0.45 plus or minus 0.16 to 0.80 plus or minus 0.40. Thus, genetic determinants exerted substantial influence on the expression of the traits in each environment. Most of the commercial cultivars exhibited no benefit over the accessions for these traits, and there was a relationship between the accessions' geographic origin and their potential for timothy improvement. Asian and Northeast European accessions possessed the greatest potential for increasing timothy yield and nutritive value under irrigated western North American conditions.