Annual Ryegrass Management Effects On Tifton 85 Bermudagrass Spring Regrowth – Two-Year Evaluation.

Spring transition from annual ryegrass to warm-season perennial grasses can be troublesome and inconsistent due to heat-tolerant annual ryegrass. A two year evaluation was conducted to examine the factorial combination of three ryegrass removal dates (early March, D1; mid March, D2; and late March, D3) and three removal methods [chemical, C; mechanical, M; and simulated grazing, G, plus two controls (T-85 only not overseeded, and  overseeded  ryegrass not removed)] on spring regrowth of Tifton 85 bermudagrass (T-85). There were interactions with year for light interception at soil level (P < 0.01). In 2011, light interception was affected by date and method (P < 0.01); highest light interception occurred with D2 (54%) followed by D1 (47%), and D3 (40%). Tifton 85 only had the highest light interception (76%), followed by chemical removal (65%), mechanical removal (49%) and simulated grazing (45%). In 2012, light interception was affected by date and method (P < 0.01).  Highest light interception occurred with early removal D1 (41%) followed by D2 (35%), and D3 (31%). Tifton 85 only had the highest light interception interception (61%), followed by chemical removal (48%), simulated grazing (41%) and mechanical removal (37%). Tifton 85 rhizome mass was by affected by year (P < 0.01; 314.9 vs. 731.5 g m2 in 2011 and 2012, respectively). Removal date had an effect (P < 0.01) on Tifton 85 rhizome mass. Early removal D1 had the heaviest rhizome weight (659.9 g m2), followed by D2 (506.5 g m2) and D3 (443.5 g m2). Implications from this study show that warm spring temperature will require early removal of ryegrass to guarantee T-85 bermudagrass regrowth in the spring.