Options for Fall Poa annua Control in Warm-season Lawns and Golf Turf

Recent research and practical experience clearly shows that mid to late fall is the most effective time to control Poa annua in warm-season turf. Herbicide mixes applied at this time will also decrease the chance of resistance development.

Traditional PRE option: Specticle^® FLO applied in early fall has been exceptionally effective for many years

• Poa annua starts germinating when 4” soil temperatures reach 72oF, but germination flushes are always accompanied by rainfall
• Application of Specticle should be made prior to this soil temperature and should be watered in with 0.25” irrigation
• Split applications always improve control given tropical storms or inconsistent fall/winter weather
• Recent research at the University of Tennessee indicates that some Poa annua plants may survive on collars, in shade, and in other minimal stress areas but are usually small and not visible in the bermudagrass canopy. Therefore, consider including a POST herbicide like Tribute^® Total to help control early escapes

Why wait? Waiting later and applying a PRE/POST tank-mix after significant Poa annua germination provides greater benefits including:

• Wider window of effective application timing since annual bluegrass germination can vary from year to year
• Improved control of later-germinating winter annuals like henbit, chickweed, etc.
• More flexibility when planning applications around reduced labor forces, golf activity, or variable fall/winter weather including:
  • Heavy rainfalls from tropical storms that could leach and degrade herbicides
  • Warm temperatures that could encourage annual bluegrass germination throughout the winter
  • Severe cold that could exaggerate winterkill
• University research has shown that tank-mixing herbicides with different sites of action is more effective than rotating herbicides with different sites of action when weed resistance management is being considered

Most effective Fall option – Envu’s PRE3 is a tank-mix of three herbicides including SpecticleFLO (6 fl oz/A), Tribute Total (1 oz/A) and simazine (32 fl oz/A)

• Designed to deliver consistent annual bluegrass control and reduce the likelihood of developing resistance
• PRE3 applications should be applied later than the traditional PRE-only applications in late summer
  • Single or split applications of PRE3 can be made starting in late-October or November based on your location, weather, amount of annual bluegrass germination, etc.
  • Tank-mix components, rates, timings, and application intervals can also be based on weather and previous experience
• PRE3 also controls problematic winter annual broadleaves and annual sedges

Other options:

• RoundUp^® could be rotated in the tank-mix for non-selective control on dormant fairways for another herbicide site of action. University research and practical experience show that 5 fl oz/A of RoundUp (4 lb ai/gal formulations) provides excellent Poa annua control and exceptional turf safety, even on green bermudagrass
• Glufosinate could also be rotated in the tank-mix for another non-selective site of action

More information – always refer to the label for specific recommendations and contact your Envu area sales manager if you need assistance

Solution sheet - Poa annua