Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 16, 2005
Publication Date: N/A
Interpretive Summary: Cultivated timothy (Phleum pratense L.) germplasm has potential value for rotational grazing systems in North America. This study reports on the development of an improved population of timothy that had higher forage yield than commercial cultivars under both a frequent and an infrequent harvest management. It also describes some unique timothy germplasm collected from old turf sods, that showed some potential for improving forage yield under frequent harvest management, but was generally inferior to forage germplasm under infrequent harvest management. Timothy cultivars optimally adapted for use under rotational grazing will likely require different traits than traditional hay-type cultivars. This information will be of value to forage scientists working on timothy and to extension personnel who may make recommendations of timothy cultivars to forage producers.
Technical Abstract: Cultivated timothy (Phleum pratense L.) is an important grass for hay production in temperate North America. It is underutilized in management-intensive rotational grazing systems because of its poor persistence when frequently defoliated. The objective of this study was to compare families selected for forage yield under frequent defoliation, families derived from old turf sods, and cultivars for agronomic performance under frequent and infrequent harvest managements (4 vs. 2 harvests per year). Forage timothy was generally superior to turf timothy for most traits. Forage selections averaged 9.4 and 4.9% higher forage yield compared to cultivars under infrequent and frequent harvest managements, respectively, indicating that selection for higher forage yield under frequent harvest improved forage yield under both harvest frequencies. There were differences among the four types of turf (golf course fairways and roughs, cemeteries, and lawn/roadways), but these differences were not closely related to mowing height or frequency, perhaps due to the small sample size. Some turf collections ranked high for net herbage accumulation under frequent harvesting, but most turf collections were also characterized by a high frequency of regrowth panicles under either or both harvest frequencies. Timothy germplasm from old turf sods may have value in developing new timothy cultivars with improved tolerance to frequent defoliation and efforts should continue to gather and evaluate collections from a range of turf types and locations.