Poa Annua Control Research Articles

Poa annua control in golf course putting green collars via fraise mowing

AbstractPoa annua L. control on golf courses is challenging, particularly in collars adjacent to putting greens where herbicide options are limited. Field research was conducted in Knoxville, TN from 2022 to 2024 to evaluate P. annua control efficacy following summer fraise mowing of putting green collars. Plots were arranged in a hybrid bermudagrass [C. dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy, cv. ‘Tifway’] collar adjacent to a creeping bentgrass (Agrostis stolonifera L.) putting green. A walk‐behind fraise mower (RR600 HDX; SISIS) was used to fraise mow plots (0.6 × 3 m) to depths of 8 or 15 mm. A non‐fraise‐mowed check (0 mm) was included for comparison. Plots were fraise mowed on June 20, 2022 and July 10, 2023 with recovery visually assessed thereafter relative to non‐fraise‐mowed check plots in each replication. Poa annua control was visually assessed 133 and 233 days after treatment relative to non‐fraise‐mowed check plots as well. In the absence of herbicide, summer fraise mowing of hybrid bermudagrass collars provided effective control (>89%) of P. annua for 133 days. Hybrid bermudagrass recovery from this mechanical control method was swift, which suggests that it could be incorporated into a weed management program with pre‐ and postemergence herbicides similar to harvest weed seed control methods used in crop production.

Rapid PublicationDiuron-resistantPoa annuais resistant to norflurazon

Poa annua control with norflurazon was different between two field trials in 1999. At the field site with suspected diuron-resistant P. annua, control was less than at the site with known diuron-susceptible P. annua. Diuron-resistant and -susceptible biotypes of P. annua were subjected to a range of norflurazon rates in the greenhouse. The diuron-resistant P. annua biotype (R/S : of 2.5) was collected in 1995 from a Lolium perenne L. seed production field near Tangent, OR. The R/S : for norflurazon in these experiments was 4.8; thus, confirming that diuron-resistant P. annua is resistant to norflurazon.