|DUNNE, JEFFERY - North Carolina State University|
|REYNOLDS, CASEY - Turfgrass Producers International|
|MILLA-LEWIS, SUSANA - North Carolina State University|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2018
Publication Date: 2/1/2018
Citation: Dunne, J., Tuong, T.D., Livingston, D.P., Reynolds, C., Milla-Lewis, S. 2018. Field and laboratory evaluation of Bermudagrass (Cynodon spp.) germplasm for cold hardiness and freezing tolerance. Crop Science. 59:392-399.
Interpretive Summary: Bermudagrass is a popular turfgrass used in lawns and golf courses. Its low level of freezing tolerance precludes its use in many cold regions of the US. Crosses with African and common types have produced promising germplasm, but screening for freezing tolerance has been scarce. This study is a report on the results of field and laboratory based evaluations of winter hardiness and freezing tolerance. Several genotypes showed significantly higher level of winter survival than many commercial cultivars and show promise in the continued improvement of freezing tolerance of this important turf species.
Technical Abstract: Bermudagrass (Cynodon spp.) is a high quality, durable turfgrass with excellent heat and drought tolerance. However, its lack of freezing tolerance limits its use in the transition zone. The development of cultivars with enhanced freezing tolerance would constitute a significant improvement in the management of bermudagrass in this region and could extend its area of adaptation further north. Hybridization of African (C. transvaalensis) and common (C. dactylon) types have been used with tremendous commercial impact in bermudagrass breeding. There has been substantial work on screening of common-type bermudagrass germplasm for freezing tolerance, but not for the African germplasm. The purpose of this research was to conduct field testing and laboratory-based evaluations of winter hardiness and freezing tolerance, respectively, of an African and common bermudagrass germplasm collection. A high level of cold hardiness was observed among these germplasm. In field evaluations, Plant introductions (PI) PI 290905, PI 647879, PI 255447, PI 289923 and PI 615161 were the top performers having consistently greater spring green-up and winterkill ratings compared to Patriot, Tifsport, Quickstand and Tifway; though, not always significant. A comparison between the field-based ratings and the calculated LT50 values from laboratory-based freezing tests showed significant correlations of -0.26 and -0.24 for spring green-up and winterkill, respectively, suggesting that these controlled freeze experiments could be used to pre-screen materials prior to field testing. Overall, results indicate that some of the PIs evaluated in this study can be used as additional sources of cold hardiness in bermudagrass breeding.