Post-emergent Management Of Poa annua in Bermudagrass Turf - New Products - Urban Ag Council Meeting September 23, 2014 Joe Chamberlin Ph.D. Manager, Field Development Valent Professional Products

Outline of Today’s Talk Poa annua biology Post-emerge Poa management Product selection - considerations Advantages/ limitations Research BHP (Best Herbicide Practices)

Poa annua - Biology Annual grassy weed Germination (Some short lived perennial biotypes) Germination Mostly fall: September-November (80% NC) Often not visible until spring due to turf cover Herbicide resistance Significant problem Poa is one of top customer complaints

Product Selection - Considerations Stage of Poa development Turf species and dormancy Presence of other weeds Herbicide movement potential Use site Herbicide history – resistance Cost – product, labor, call backs, retention

Herbicide Options – Pre-emerge Old products Triazines Simazine and atrazine Dinitroanalines (DNA) Dithiopyr, oryzalin, pendimethalin, prodiamine PPO Oxadiazon (Ronstar)*

Herbicide Options – Pre-emerge New products Freehand (dimethenamid + pendimethalin) Specticle (indaziflam) SureGuard (flumioxazin)

Why post emerge? Miss preemerge application window Broadleaf weeds Weather Scheduling New customer Broadleaf weeds Many pre-emerge herbicides not effective Ex. Lawn burweed Resistance Triazines ALS DNAs Escapes from pre treatment

Herbicide Options – Post-emerge Old products ALS inhibitors Certainty, Katana*, Monument*, Revolver, Tranzit* Finale (glufosinate) Prograss (ethofumasate) Roundup (glyphosate) Kerb (pronamide)* Triazines Simazine, Atrazine * Not labeled for residential turf

Herbicide Options – Post-emerge New products Specticle (indaziflam) Very early post SureGuard (flumioxazin)

Specticle

Specticle (indaziflam) Advantages Highly effective against Poa (preemerge, early post) Controls many winter annual broadleaf weeds Very long residual Also effective against crab and goosegrass New MOA – Cellulose biosynthesis inhibitor Resistance management Labeled for all turf use sites and landscape ornamentals No stain or odor

Specticle (indaziflam) Limitations May interact with bermuda winter kill/ slow emergence from dormancy in shady Limited post activity – Seedling Poa only Potential for down slope movement Less potential for movement than ALS, triazine or Kerb Injurious to cool season turf Product cost

Indaziflam at 35 g ai/ha Pictures: Jan. 20, 2011 October application November application

Specticle BHP 6-10 fl oz/ A for Poa (Specticle Flo) Apply August – October for optimal Poa control Avoid application or runoff onto desirable cool season turf

SureGuard

SureGuard (flumioxazin) Advantages Pre and post-emergent control (8-12 oz/A) New MOA for post control – PPO inhibitor Wide Poa application window (November – March) No delay in bermuda greenup if applied when dormant Controls most winter annual broadleaf weeds Fast post-emergent activity Low potential for movement Pre control of crab and goosegrass (Feb-March application) Can tank mix with other post herbicides No stain or odor Labeled for all turf use sites, woody landscape ornamentals (directed), bare ground (crack/ crevice)

SureGuard (flumioxazin) Limitations Will injure actively growing bermudagrass Accelerated dormancy in fall No delay in greenup Slower acting against Poa in colder weather Product Cost

Data combined over trials in CA and AL SureGuard – Annual Bluegrass Control Dormant Bermudagrass Turf – April Ratings Poa 2+ tiller stage Annual Bluegrass was in flower at time of March 7 application, with 30-40% cover of untreated plots. None of treatments delayed bermudagrass green-up Data combined over trials in CA and AL

Untreated Control Image: Jan-18-2012

SureGuard 12 oz/ A – Dec. 5 Image: Jan-18-2012 (39 DAA)

SureGuard 12 oz/ A – Jan. 4 Image: Jan-18-2012 (14 DAA)

SureGuard 12 oz/ A – Dec. 7 Image: Mar-22-2011 (111 DAA)

SureGuard 12 oz/A - Applied March 11 Photo: March 23 SureGuard 12 oz/A - Applied March 11

SureGuard® Herbicide Dormant Turf Arizona State University, Karsten Golf Course Untreated, non-overseeded Bermudagrass rough; all Poa annua SureGuard treated area Ryegrass fairway Bermudagrass green-up SureGuard was applied at 12 oz/A plus non-ionic surfactant 0.25% v/v on Nov. 2, 2011; picture was taken Feb. 15, 2012. Bermudagrass is coming out of dormancy in the plot area.

SureGuard BHP 10-12 oz/ A for Poa Apply November- December for optimal Poa control Tank mix with metsulfuron if perennial broadleaf weeds (ex. dandelion, clover) present Tank mix with surfactant Avoid application after bermuda begins active growth in spring

SureGuard Application Window Bermudagrass Turf Poa and Winter Annuals germinate Green/active Semi-dormant Semi-dormant Green/active ------------------- SureGuard ----------------- Dormant 28

SureGuard Application Window Bermudagrass Turf Poa and Winter Annuals germinate Green/active Semi-dormant Semi-dormant Green/active ------------------- SureGuard ----------------- Dormant Optimal timing for Poa annua 29

SureGuard Application Window Bermudagrass Turf Poa and Winter Annuals germinate Green/active Semi-dormant Semi-dormant Green/active ------------------- SureGuard ----------------- Dormant Optimal timing for Poa Optimal timing for Goosegrass/ Crabgrass 30

Questions?