Turfgrass Weed Management in North Carolina

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1 Turfgrass Weed Management in North Carolina Apr 6, 2009 L. S. Warren North Carolina State University Nov 10, 2009

2 Lonnie Poole Golf Course Hole In One Club Sandy Moonert 6/27/09 # yards 9-iron Russelll King 7/11/09 # yards 9-iron Mark Scwierz 7/20/09 #2 207 Yards 6-iron Brian Bass 7/26/09 #2 165 yards 6-iron Andrew Frank 7/26/09 #2 207 Yards 5-iorn Mike Howard 7/30/09 #2 186 Yards 4-iron Andrew Cox 8/12/09 #6 148 Yards 9-iron Brad Wood 8/17/09 # Yards Driver Jim Cleveland 8/10/09 #2 188 Yards 5-iron John Sari 8/19/09 #2 245 Yards 3-wood Philip K. Brantly 8/26/09 #2 214 Yards 6-iron Tony Withers 9/8/09 # Yards 7-iron Tim O Neil 9/10/09 #2 165 Yards 7-iron Leon Warren 9/11/09 # Yards PW

3 North Carolina Turfgrass Industry Statistics Specific Weed Problems for Turf Growers Why are weeds present? How to prevent / control? Actual Chemical Control Recommendations Jan Mar Apr Jun Jul Sep Oct Dec Herbicide / Weed Resistance Issues

4 North Carolina Turfgrass Industry Statistics Rank 8 th in U.S. total turfgrass acreage - over 2 million acres of maintained turf - single family dwellings account for ~70% Roadsides Athletic fields Parks Sod farms Commercial properties Airports Churches Institutions Schools Cemeteries Golf courses: Rank 9 th in U.S. total golf course acreage with 51,700 acres on 531 courses

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11 North Carolina Turfgrass Industry Statistics NC is in a transition zone, meaning both cool - and warm-season turfgrasses can be grown. Kentucky 31 tall fescue Centipedegrass Bermudagrass 770,000 acres 348,000 acres 231,000 acres Cool: fine fescue, annual ryegrass, perennial ryegrass, bentgrass and Kentucky bluegrass Warm: bahiagrass, zoysiagrass, carpetgrass and St. Augustinegrass

12 North Carolina Turfgrass Industry Statistics Over 1.2 billion spent annually to maintain areas Single family dwellings account for ~700 million Commercial properties account for ~235 million Golf courses account for ~135 million Labor: single biggest expense category 580 million (47%) Pesticides: ~40 million spent annually Single family dwellings account for ~27 million

13 North Carolina Turfgrass Industry Statistics Turf maintenance (dollars per acre) Professional sports 3500 Golf courses 2500 Cemeteries 1500 Commercial properties 1400 Institutions, schools Churches 500 Single family dwellings 500 Airports 250 Roadsides 100 Parks 75

14 Weed Biology What is the Nature of Plants as Weeds? (Cultivated crop example) Approx. 300,000 plant species Approx. 30,000 are weeds to somebody, somewhere Approx. 300 are serious in cultivated crops Approx. 10 to 30 weed species must be controlled to avoid yield reductions in cultivated plants

15 Annual Bluegrass

16 Mar 27, 2009 Geranium, Dandelion, Common Chickweed, Buttercup

17 Weed Biology Ten Most Common Weeds in North Carolina Turf 1. Bluegrass species WA, P 2. Crabgrass species (smooth, large) SA 3. Chickweed species (common, mouseear) WA 4. Henbit WA 5. Goosegrass SA 6. Dallisgrass P 7. Clover species (hop, white) WA, P 8. Dandelion P 9. Wild garlic P 10. Cudweed species B 2008 Proceedings - SWSS

18 Weed Biology Ten Most Troublesome Weeds in North Carolina Turf 1. Dallisgrass P 2. Bluegrass species P, WA 3. Bermudagrass P 4. Kyllinga species (green, false-green) P 5. Bahiagrass P 6. Crabgrass species (smooth, large) SA 7. Goosegrass SA 8. Nutsedge species (purple, yellow) P 9. Violet species (common blue, field pansy) P 10. Henbit WA 2008 Proceedings - SWSS

19 Why are weeds present in turfgrass?

20 Why Weeds are Present in Turfgrass Weeds are the result of improperly managed turf.

21 What is Properly Managed Turfgrass? 1. Turf species that is adapted to its environment Should you choose cool or warm season turf? Raleigh is in a transition zone where both grow pretty well but problems can occur with each Example: Tall fescue doesn t like 85+ degrees and warm humid conditions (susceptible to diseases). Bermuda can suffer winter kill in harsh winters and also cannot live in shade even with favorable temps.

22 What is Properly Managed Turfgrass? 2. Turf mowed at proper height & frequency Tall fescue 3 Inch Turf Mowing Height Tall fescue / fine fescue / per. bluegrass mixtures

23 Mar 27, 2009

24 Fescue 3 inch height Aug 20, 2007 Fescue 4 inch height

25 Fescue 1 inch height Aug 20, 2007 Fescue 2 inch height

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27 What is Properly Managed Turfgrass? Inch Turf Mowing Height Bermudagrass Centipedegrass Zoysiagrass Grown in eastern and central NC

28 Savannah 0.5 inch August 20, 2007 Savannah 1 inch Savannah Weed free

29 Savannah 1.5 inch August 20, 2007 Savannah 2 inch Savannah Weed free

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31 What is Properly Managed Turfgrass? 3. Turf that is fertilized at the proper time with the proper rate and technique

32 Improper Boom Height

33 Equipment Too Big

34 Good coverage can be difficult when spreading granules with large equipment... On moderate / severe slopes On specially designed and maintained areas

35 What is Properly Managed Turfgrass? Cool Season Turf Nitrogen Timings and Amounts For all cool season turf, start applications in September October and finish in February March. Do not apply nitrogen in the spring or summer because of disease concerns. 3 lbs of N per 1000 sq ft per year is sufficient.

36 What is Properly Managed Turfgrass? Warm Season Turf Nitrogen Timings and Amounts Timings and rates vary between species, but generally start in the spring and fertilize through summer. Do not apply nitrogen in the fall or winter. Total N rates range from 0.5 lb per 1000 sq ft per year for centipedegrass to 6 lbs for hybrid bermuda.

37 What is Properly Managed Turfgrass? 4. Turf site that is well drained, noncompacted and receives adequate rainfall or irrigation If turf areas stay wet continuously, weeds such as nutsedge and kyllinga species will invade because they are better adapted to wet environments.

38 Weed Control Procedures A successful weed management strategy should integrate all of these procedures and not rely heavily on one. Preventative Mechanical Biological Cultural Chemical

39 Weed Control Procedures Preventative Good sanitation Clean mowers, tillage implements and other turf equipment before moving to new sites to remove weed seeds and vegetative material.

40 Weed Control Procedures Mechanical Physical removal by hand or tillage Effective on annual weeds when the growing point is removed or buried Ineffective on perennial weeds that have underground storage organs unless done repeatedly

41 Weed Control Procedures Mechanical Mowing Effective on many annual broadleaf weeds that have an upright growth habit Ineffective on common broadleaf weeds such as prostrate knotweed, spotted spurge and common lespedeza because of low growth Also ineffective on most grassy weeds

42 Weed Control Procedures Biological Biological weed control utilizes natural enemies such as insects, fungi, bacteria and nematodes. This method works very slowly and is generally limited to large rangeland areas where a single weed dominates and other control methods are not practical. Ex. thistle control in rangelands with weevils

43 Weed Control Procedures Biological Turf example with limited success: Xanthomonas campestris (bacteria) on annual bluegrass Mow and immediately apply bacteria which enters the cut surfaces to produce wilt which kills the plant Biologicals don t give rapid kill like chemicals, and are not enticing or practical for the turf industry. People usually want a quick fix.

44 Weed Control Procedures Cultural The best way to prevent weed problems in turf is to properly manage the turfgrass. Select an adapted grass species Mow at proper height and frequency Fertilize at proper time and rates Irrigate as needed in morning, not late evening Improve drainage by adding soil or soil mixes

45 Weed Control Procedures Chemical The quickest, practical way to prevent or control weeds in turf is to apply herbicides. Herbicides are short-term solutions. Results can be seen quickly, and people are happy. Herbicides do not correct the problem as to why weeds were present in the first place. As long as the problems are not corrected, the need for herbicides will exist.

46 JANUARY - MARCH Post control of annual bluegrass, wild garlic, winter annual and cool-season perennial broadleaf weeds Pre control of summer annual crabgrass, goosegrass and summer annual broadleaf weeds

47 Perennial and Winter Annual Broadleaf Weeds: Poa annua metribuzin (Sencor 75 Turf) 0.67 lb/acre chickweed sp., henbit, lawn burweed, corn speedwell glyphosate (Roundup Pro, Touchdown Pro) 1 pt/acre % v/v nonionic surfactant Dormant nonoverseeded bermuda only!

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49 Velocity 80SP 1.33 oz/acre (3X) Feb 15, Mar 7, Mar 18 Photo Apr 12, 2005 Check Bermuda overseeded with perennial ryegrass

50 Wild Garlic Feb 22, ,4-D amine Many formulations 3 qt/acre + surfactant Bermuda, fescue, ryegrass Treat for 2 years Image 70DG 0.35 to 0.7 lb/acre + surfactant Bermuda, centipede, zoysia Apply before spring greenup Manor / Blade 0.33 to 0.5 oz/acre + surfactant Bermuda, centipede**, zoysia, St. Augustine, Ky. bluegrass

51 Cool Season Perennial and Winter Annual Broadleaf Weeds India mock strawberry Dandelion Curly dock Buckhorn plantain White clover Wild violet Yellow woodsorrel Carolina geranium Henbit Chickweed species Speedwell species Lawn burweed Field pansy Hairy bittercress Hop clover

52 Cool Season Perennial and Winter Annual Broadleaf Weed Control The majority of POST herbicides used for broadleaf weed control (perennial, summer AND winter annuals) fall under four herbicide families. 1. Phenoxys 2. Benzoic acids 3. Pyridines 4. Triazolinones

53 Phenoxys, Benzoic Acids and Pyridines All display similar characteristics. Are foliar and root absorbed herbicides Are growth regulator / hormone-type herbicides. Exhibit epinastic bending symptoms. Upper leaf surfaces grow faster than lower leaf surfaces, causing downward leaf curling or folding. Outer stem sections grow faster than inner stem sections, causing twisting or splitting.

54 Phenoxys, Benzoic Acids and Pyridines Common Name Trade Name Phenoxys: 2,4-D amine Weedar 64 dichlorprop Weedone 2,4-DP mecoprop MCPP 4K Benzoic acids: dicamba Banvel Pyridines: triclopyr Turflon Ester clopyralid Lontrel fluroxypyr Spotlight

55 Triazolinones These are cell membrane disrupters. Injury symptoms include initial stunting and gradual yellowing, followed by death. Common Name Trade Name Carfentrazone Quicksilver Sulfentrazone Dismiss

56 Pre crab and goose control Root Inhibitors Herbicide families include Dinitroaniline and Pyridine Affect cell division and cause root clubbing, even to tolerant turf Normal roots Do not use on athletic fields or other high traffic areas!!! Will control crab and goose very early post (1-4 leaf) Clubbed roots

57 Pre crab and goose control Athletic fields, worn turf, high traffic areas Shoot inhibitor herbicide: oxadiazole family Common name / Trade name: oxadiazon / Ronstar Inhibits photosynthesis does not inhibit root growth Absorbed through shoots only No post activity at all do not apply after germination!!

58 PRE Weed Management Strategies Summer Annual Broadleaf Weeds and Annual Sedge Many of the PRE summer annual grass herbicides have activity on small-seeded summer annual broadleaf weeds such as common lespedeza, spotted spurge and prostrate knotweed and also annual sedge. The timings are ideal for controlling many types of weeds with one product at one time if you can identify weed populations correctly.

59 PRE Weed Management Strategies Isoxaben (Gallery Dry Flowable) Gallery Dry Flowable is the only TRUE PRE broadleaf herbicide labeled in turfgrasses. This herbicide has very limited activity on grass plants. All established turfgrasses (cool and warm season) are tolerant.

60 APRIL JUNE Post control of summer annual and perennial Grassy weeds Broadleaf weeds Sedge and kyllinga weeds Post control of perennial ryegrass (a cool season perennial) ***Pre control of crabgrass when seeding, sprigging or sodding turf in spring

61 POST Weed Management Strategies Summer annual and warm season perennial weeds should be controlled when young, sometime in the spring (April June) BEFORE they begin producing seeds or reproductive structures. Why???

62 POST Weed Management Strategies Herbicides do not control weed seeds (they control weed seedlings and sometimes mature plants) and generally are very weak on translocating to reproductive structures!!! Seedling plants generally easier to control Less herbicide needed for control saving money Turfgrass has longer to recover from shading effects

63 POST Weed Management Strategies Goosegrass Goose and crabgrass Crabgrass and bdlvs Revolver Acclaim Extra Drive 75DF, Drive XLR8 Illoxan Sencor 75 Turf Q4 Crab, goose bdlvs Dallisgrass Bahiagrass Grasses/sedges Tenacity MSMA fb Revolver Manor MSMA fb Revolver Vantage Plateau Yellow nutsedge Basagran T/O Yellow and purple nutsedge/kyllinga Dismiss, Image, Sedgehammer, Certainty Monument

64 Warm Season Perennial and Summer Annual Broadleaf Weeds Virginia buttonweed Spotted spurge Common lespedeza Prostrate knotweed Control with same post broadleaf herbicides discussed in Jan Mar section

65 Perennial Ryegrass Control Perennial ryegrass becomes a problem in overseeded bermudagrass turf in late spring (April through June). Bermudagrass struggles to greenup because of the competition from the ryegrass. Close mowing and hot temperatures will not completely eradicate this weed.

66 Per. Ryegrass Removal From Bermuda metribuzin (Sencor 75 Turf) Kills in 2 to 3 days - unattractive until fills in metsulfuron (Manor / Blade) + NIS rimsulfuron (TranXit GTA) + NIS trifloxysulfuron (Monument) + NIS foramsulfuron (Revolver) Kills in 2 to 3 weeks gaining favor pronamide (Kerb WSP) Kills in 4 to 6 weeks - smoothest transition

67 Preemergence Crabgrass Control in Newly Seeded Turf Mesotrione (Tenacity 4SC) 5 to 8 fl oz/a Apply to spring seeded tall fescue, Ky. bluegrass, centipedegrass, St. Augustinegrass grown for sod. Apply at or right before seeding, not germination. If germinated, wait until turf is mowed twice or 4 weeks after emergence (whichever is longer).

68 Preemergence Crabgrass Control in Newly Sprigged Turf Oxadiazon (Ronstar 2G, 50WP) Apply to bermudagrass or zoysiagrass sprigs only.

69 JULY SEPTEMBER Weed Management Options

70 Summer Annual and Perennial Grasses Nutsedge Species Kyllinga Species Summer Annual and Perennial Broadleaves (July - September) Initiate applications (What are you waiting for!!??) OR Repeat applications (hopefully started last quarter)

71 Pre Winter Weed Control Winter Annual Weed Examples Grasses Annual bluegrass (Poa annua) Broadleaves Chickweed species Henbit Lawn burweed Speedwell species Knawel Hop clover

72 PRE Weed Management Strategies Winter Annual Grass and Broadleaf Weeds Use same herbicides for annual bluegrass control that were used for crabgrass and goosegrass Many of the PRE grass herbicides have activity on small-seeded winter annual broadleaf weeds such as common chickweed, henbit, lawn burweed, corn speedwell, knawel and hop clover. The timings are ideal for controlling many types of weeds with one product at one time if you can identify weed populations correctly.

73 PRE Weed Management Strategies Winter Annual Broadleaf Weeds Gallery Dry Flowable provides PRE control of winter annual broadleaf weeds such as Henbit Common chickweed Speedwell species

74 OCTOBER - DECEMBER Best time for post control of Winter annual and cool-season perennial broadlvs Wild garlic Annual bluegrass

75 Wild Garlic, Cool Season Perennial and Winter Annual Broadleaf Weeds (October December) Use products listed in the January March section Should work better (lower rates) on smaller weeds (annual seedlings and cool-season juveniles) Application timings are critical if turf is to be overseeded or established during this time

76 Post Annual Bluegrass and Winter Annual Broadleaf Weed Control Sulfonylurea herbicide family Certainty, Monument, Revolver, TranXit GTA Amino acid inhibitors Plants turn yellow, pink, then purple Work slowly, takes several weeks for full effects Monument + NIS Photo: April 2004

77 Post Winter Annual Broadleaf Weed and Annual Bluegrass Control atrazine and simazine control many common winter annual broadleaf weeds such as: Common chickweed Henbit Corn speedwell Lawn burweed Hop clover Many other broadleaf weeds listed on their labels.

78 Triazine Family Photosynthetic inhibitor Atrazine 2 qt/acre Photos Apr 11, 2005 Check Little barley, annual bluegrass, henbit, Brazilian catsear, Carolina geranium, mouseear chickweed, corn speedwell

79 Pre & Post Annual Bluegrass Control Pronamide (Kerb WSP) Apply to nonoverseeded warm-season turf only Highly mobile: rainfall or irrigation can cause to move if improperly timed

80 Pre & Post Annual Bluegrass Control Prograss 1.5EC Nov and Dec appl 2.67 qt/acre each Overseeded perennial ryegrass

81 Herbicide Resistance Resistance The ability of some weeds in an existing population to withstand the effects of an applied herbicide when the population is normally susceptible.

82 Herbicide Resistance Resistant plants become a problem when the susceptible members of the population are killed by herbicide applications. The resistant plants escape, reproduce, and over time, can become the majority of the population. The susceptible plants eventually are replaced by the resistant plants.

83 Herbicide Resistance Resistance is encouraged when the same herbicide or herbicide family is used year after year for the same weed control. Two examples of herbicide resistant weeds: Goosegrass has been documented as becoming resistant to DNA herbicides. Annual bluegrass has been documented as becoming resistant to triazine herbicides.

84 Herbicide Resistance The way to avoid or delay herbicide resistance is to rotate not just herbicides from year to year, but also herbicide families! To best avoid the proliferation of resistant weeds, a different herbicide family should be used at least one year out of every four.

85 Herbicide Resistance Why would rotating herbicide families be a potential problem for turfgrass managers??? Several Reasons Turfgrasses are generally considered perennial plantings. They remain the same year after year. Depending on the turfgrass species, you may not have many effective available options to begin with. Some of your alternative options may not provide acceptable control.

86 Herbicide Resistance Why would rotating herbicide families be a potential problem for turfgrass managers??? Several Reasons Many turfgrass managers overseed. This common practice limits even further the number of available effective herbicides or herbicide families that can be applied safely.