Weed Management on Athletic Fields Tim R Murphy Crop and Soil Sciences The University of Georgia Athletic Field Agronomic Problems Excessive wear and damage Lack of recovery time Compaction Poor drainage Athletic Fields People Problems Lack of equipment personnel chemicals irrigation MONEY Poor maintenance practices Untrained maintenance personnel Constant use schedules Low budgets high expectations Hit or Miss Or A Planned Program Practical Tips Use only labeled herbicides Get the right equipment Train your applicator Calibrate all equipment Control weeds during the off season or off times Georgia Posting Rule Chapter 40 21 5 Administered by Georgia Department of Agriculture 24 hour re entry restriction for all pesticides Contact Georgia Department of Agriculture for additional information Bermudagrass Athletic Fields November Late Nov Dec Mid Jan Feb Mid Jan Feb Begin winter weed program Begin wild garlic onion program Complete winter weed program Complete wild garlic onion program Bermudagrass Athletic Fields Mid Feb March Begin Preemergence Summer Program May June Begin Postemergence Summer Program June July Begin nutsedege program Bermudagrass The Big Three Simazine Princep Wynstar etc MSMA or DSMA 2 4 D possibly a 2 way or three way Bermudagrass Summer Use MSMA for postemergence control of weedy grasses 2 appl for crabgrass 7 to 10 day interval 3 appl for dallisgrass and bahiagrass 5 day interval Will help on nutsedge control Non overseeded Bermudagrass Winter Simazine or atrazine Apply 1 0 lb ai acre in November Repeat in January if necessary Will control annual bluegrass common chickweed lawn burweed henbit etc Poor control of wild garlic onion and perennial broadleaf weeds Summer or Winter Use 2 4 D alone or in 2 way or 3 way herbicides for wild garlic onion and broadleaf weed control Can be used on overseeded fields after 3 to 4 mowings on perennial ryegrass Tank mix in summer with MSMA do compatibility test Quadmec Trimec Plus Avoid green up and hot summer day applications Athletic Fields Preemergence Herbicides Be careful on severely damaged fields Most PRE herbicides affect root development from stolon nodes Select oxadiazon products Does not affect root development from stolon nodes On non damaged healthy fields numerous herbicides may be used Dinitroanilines Benefin Balan Oryzalin Surflan Pendimethalin Pendulum Prodiamine Barricade Trifluralin an a i in Team Used on most cool and warm season turfgrasses Shoot and root absorbed no translocation Inhibit cell division Dithiopyr Dimension MOA is similar to dinitroanilines Shoot and root absorbed no translocation Inhibit cell division tubulin formation DNA Root inhibition pendimethalin on zoysiagrass Surflan on St Augustinegrass Dimension on bermudagrass Swollen club shaped roots prevent rooting down More Practical Tips Observe posting regulation Water in 0 5 inch all preemergence herbicides Make applications on off days or off times Use a 20 to 40 gpa spray volume Avoid post herbicide use at air temperatures 90 F and during spring transition Problem Athletic Field Weeds Annual Bluegrass Goosegrass Crabgrass Dallisgrass Sedge s Annual Bluegrass Fall preemergence late Nov atrazine simazine mid Jan atrazine simazine Sencor Kerb Dormant period Roundup Pro Finale Non Overseeded Bermudagrass Numerous PRE and POST options for annual bluegrass Triazines standard but resistance increasing Kerb works costly lateral run off Pre s work but DNA resistance is here Glyphosate works partial dormancy Diquat ineffective Crabgrass Mid Feb March apply Pre repeat 8 wks later if 1 2 rate is used Summer MSMA repeat 2x 7 day interval will not control goosegrass Summer Drive one application apply to seedling or big crabgrass control of 1 to 4 tiller crabgrass is not consistent will not control goosegrass Goosegrass Mid Feb March apply Pre repeat 8 wks later if 1 2 rate is used Summer MSMA Sencor repeat 2x 7 day interval controls crabgrass Summer Sencor repeat in 7 d fair control crabgrass more injury than MSMA alone Sedge Herbicides Turfgrasses Basagran T O yellow annual sedges Manage yellow purple annual sedges MSMA DSMA yellow purple annual sedges Image yellow purple annual sedges Monument yellow purple annual sedges Pennant yellow annual sedges Green perennial kyllinga Kyllinga spp Kyllinga spp Sedge family Annuals and perennials Reproduce by seed and rhizomes No tuber formation Thrive in wet soils Increasing in severity Lack of MSMA use Kyllinga spp Control Image Image MSMA Manage Monument Continued applications of MSMA DSMA Repeat applications will be needed MSMA DSMA CMA Organic arsenicals Post only no soil activity Crabgrass other annual grasses Weak on goosegrass Nutsedge Dallisgrass tough to control Dallisgrass Control with MSMA Apply during good growing conditions 2 to 3 applications 5 to 7 days apart Stay on schedule Avoid temperatures over 900 F Need 24 hour rainfree period Dallisgrass Control with MSMA 1976 late July 1977 August 1 7 day intervals Overseeded Bermudagrass It sure is pretty but Cost and difficulty of controlling annual bluegrass increases Perennial ryegrass becomes a weed during transition Usually chemical removal is required Broadleaf and wild garlic control No problem Delay application until after 2 to 4 mowings Overseeded Bermudagrass Options for annual bluegrass Kerb 60 to 90 days or charcoal Dimension 8 wks Barricade 8 wks not recommended on label Balan low rate 6 weeks Rubigan cost limits use to greens Prograss greenup issue TranXit and Revolver 2 weeks before seeding Bermudagrass Transition Issues Heat tolerance of ryegrass Renegade ryegrass Poa trivialis lives longer than expected Competition to bermudagrass Long term effects on bermudagrass When do you accelerate transition Bermudagrass Growth When do you accelerate transition Minimal root growth 50 F soil temp Optimum root growth 75 85 F soil temp Shoot growth ceases 55 F air temp Optimum shoot growth 80 95 F Need night air temps of mid 60s F Accelerating Transition Delay application until bermudagrass is in active spring growth Know 30 day forecast No green brown green on most sites Need green green Bermudagrass Transition Options Slow 4 to 6 wks Kerb Embark repeats Cultural techniques Fast 10 to 30 days Katana TranXit Manor Revolver Momentum Battalion Health and vigor of bermudagrass is exceedingly important to a smooth transition Questions