Use of Velocity for Post Emergence Control of (AB) in Overseeded Turf

Abstract

Velocity herbicide was applied alone, or with mixtures of Tourney fungicide and/or Primo PGR for the post emergence control/suppression of Poa annua (var. annua) in bermudagrass overseeded with perennial ryegrass. When applied alone as a repeat applications, Velocity herbicide applied at 15 and 30 gm ai/a was safe on perennial ryegrass overseed (based on color response). Velocity was safe for the overseed ryegrass when tank mixed with Tourney fungicide, both with and without the addition of Primo PGR. Tourney fungicide when applied alone at either 8 or 16 oz./product/acre produced no negative affects. As expected, Primo alone produced a dark color turf (7.8, 7.5, 7.0, and 7.0) on all four dates, respectively. Several treatments caused moderate injury to the (AB) across the entire test period. These included Velocity alone at the 15 gm/ai/a rate, and Velocity @ 30 gm ai/a plus Tourney @ 8 oz.prod/acre. The greatest amount of injury to (AB) occurred on 3/11/2008 for Velocity at 30 gm ai/a, either with or without Tourney fungicide. Although visible injury to Poa annua resulted after treatments were applied, seed head suppression was the most consistent treatment response. While injury to the Poa was severe for some treatments (Velocity plus Tourney fungicide), the Poa annua did return, ranging from re-growth as "weak plants" to an actively growing turfs (as is sometimes typical after a surviving injury response). Based on results, perhaps a tank mix application of Velocity at 30 gm ai/a along with 8 oz. product/acre of Tourney and 6 oz./acre of Primo, followed by a repeat application 35 days later may provide the ultimate seed head suppression.