Location: Forage and Range ResearchTitle: Cultivar x binary mixture interaction effect on agronomic traits in orchardgrass) Author
Submitted to: Grassland Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2014
Publication Date: 6/2/2014
Citation: Robins, J.G., Xie, W., Escribano, S., Bushman, B.S., Zhang, X. 2014. Cultivar x binary mixture interaction effect on agronomic traits in orchardgrass. Grassland Science. 60:104-111. Interpretive Summary: The forage yield and quality of 25 orchardgrass varieties were evaluated at a Millville, UT, field site from 2010-2012 under monoculture and mixed alfalfa pasture conditions. The orchardgrass monocultures possessed higher agronomic value than the mixed pastures for all traits but digestibility and stand. The best varieties were identified for both monocultures and mixed pastures. However, the results were typically not consistent across the two management practices. For example, the variety Latar possessed high forage yield in monoculture, but not in the mixed pastures.
Technical Abstract: A study was conducted to evaluate and characterize the agronomic value, including dry matter yield and forage quality of 25 orchardgrass cultivars grown in monoculture and binary mixtures with alfalfa under supplemental irrigation from 2009 to 2012 at a Millville, UT, field site. Orchardgrass monoculture plots possessed 3 to 469% higher mean values for all traits but in vitro true digestibility and stand. The mixture plots possessed less than 1% higher in vitro true digestibility, and there was no difference among stand percentage between the monocultures and mixtures. The cultivar x mixture interaction was significant for all traits but flag leaf height, which was primarily due to changes in ranking among the cultivars. Differences among cultivar means were significant for all traits in both the monoculture and mixture settings. Yet, concordance for high cultivar performance in both monoculture and mixture was low. While some trends were evident, such as the high dry matter yield and low crude protein of the cultivars 'Century' and 'Haymate XL' in monoculture and mixture, these tendencies were limited. There were also examples of different performance depending on the setting such as the cultivar Latar, which showed high dry matter yield in monoculture but low dry matter yield in mixture. Thus, the strong underlying cultivar x mixture interaction found in this study complicates the identification of best cultivars in both settings and requires new selection strategies to develop cultivars adapted to monoculture and legume mixture production.