CYNODON SPP. MANAGEMENT PROGRAMS FOR THE UPPER TRANSITION ZONE IN THE SOUTHEASTERN UNITED STATES

The transition zone is an area in the southeastern United States centered on approximately 37° N latitude where bermudagrass (Cynodon spp.) reaches its northern limit of adaptation. The duration of bermudagrass dormancy combined with the possibility of turf loss from cold temperatures makes managing bermudagrass in the transition zone challenging. This paper describes various turf management methods used by athletic field managers to provide safe and playable athletic fields in the upper transition zone of the United States. Bermudagrass mowing height should be maintained at 20 - 25 mm for hybrid bermudagrass and raised about 12.5 mm higher than normal as winter approaches to enhance winter survival. Nitrogen should be applied at 50 kg ha^-1 approximately every four to six weeks during the growing season; however, fertilization with nitrogen should not exceed 50 kg ha^-1 within 6 weeks of the onset of fall dormancy to avoid winter injury due to cold temperatures. In order to help avoid compaction injury on athletic fields, irrigation should be withheld for 2 d prior to heavy use. Soil coring (aeration) during the growing season should be practiced every 6 - 8 weeks to aid in root development and to reduce soil compaction. If bermudagrass fields experience significant winter injury, they may be renovated during spring by either sprigging or reseeding. Proper timing and implementation of numerous management techniques is essential to ensure successful fall overseeding of bermudagrass using Lolium spp. as well as its subsequent removal the following spring. These are just some of the strategies used to successfully maintain bermudagrass in this difficult region.