|West, Charles -|
Submitted to: Forage and Grazinglands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 3, 2013
Publication Date: April 30, 2013
Citation: Bartholomew, P.W., Burner, D.M., West, C.P. 2013. Productivity and persistence of summer active and summer dormant tall fescue cultivars in the southern Great Plains. Forage and Grazinglands. doi:10.1094/FG-2013-0430-01-RS. Interpretive Summary: In the southern Great Plains (SGP) efforts have been made to use tall fescue, a perennial cool-season forage, in place of annual cool-season forages such as wheat or annual ryegrass in order to avoid the cost and risk associated with annual planting. However, high temperatures and drought during the summer limit persistence and lifetime forage productivity of conventional tall fescues that are considered “summer-active” in the SGP. Some varieties of tall fescue originating from the Mediterranean area have adapted to become dormant under hot and dry conditons, and this characteristic may allow them to tolerate the heat and drought of summer in the SGP and therefore enable greater survival and increased production. The persistence and productivity of two summer-dormant varieties (Flecha and Prosper) were compared with those of two summer-active varieties (Kentucky 31 and Jesup Max Q) in experiments planted at Booneville, AR and Langston, OK. At Booneville no fescue survived beyond two growing seasons while at Langston, all varieties were productive into Spring of a third growing season but the summer-active lines did not survive the following summer. Summer-dormant varieties at Langston partially regenerated in a fourth growing season but the plant stand was insufficient to produce useful yields of forage. At both sites, forage yields of summer-active fescues were significantly greater than with summer-dormant types. Currently available summer-dormant varieties of tall fescue are not well adapted to the conditions of the SGP and do not offer any benefit in persistence sufficient to offset their low productivity compared with conventional summer-active tall fescue varieties.
Technical Abstract: Lack of persistence arising from high temperature and drought stresses during the summer limits lifetime productivity of tall fescue (Schedonorus arundinacea Schreb. [Dumort]) pastures in the southern Great Plains (SGP). A summer dormancy characteristic common in genotypes originating from the Mediterranean basin may provide a means of escaping heat and drought stresses encountered in the SGP. Two summer-active (Kentucky 31 [K31] and Jesup Max Q [JES]) and two summer dormant (Flecha [FLE] and Prosper [PRO]) cultivars of tall fescue were planted at Booneville, AR and Langston, OK to test the effects of summer dormancy on persistence and herbage productivity. At Booneville no cultivar survived beyond two growing seasons. At Langston, summer active cultivars were productive into Spring of a third growing season but did not survive the following summer. Pastures of summer dormant cultivars at Langston partially regenerated in a fourth growing season. At both sites annual and cumulative total yield over 2 or 3 years was significantly greater with summer active than with summer dormant types. Currently available summer dormant cultivars do not appear to offer survival benefits sufficient to offset low productivity in the SGP, where occasional summer rain may prevent full expression of summer dormancy characteristics.