Licensed pesticide applicator – do you ever wonder …

  1. Question 2When does my license expire? To find out, visit the GA Dept of Ag Licensing & Certification site. Information on all applicators is here.
  1. How many hours do I need for recertification? (Note that you should have earned all your hours by 90 days before license expiration!) Visit the GA Dept of Ag Licensing & Certification site.
  1. Is my address correct with the GA Department of Agriculture? If not – you may not receive your new license renewal! Visit the GA Dept of Ag Licensing & Certification site.
  1. Where can I earn more hours towards certification? Visit the GA Dept of Ag Licensing & Certification site and look halfway down the page.
  1. How much does it cost to be recertified? Visit the GA Dept of Ag pesticide faq site.
  1. Can I renew my license online? Visit the GA Dept of Ag online licensing site.

To get answers to other questions, visit the GA Dept of Ag pesticide faq site or contact them at  martha.loggins@agr.georgia.gov or call (404)-656-4958.

Argentine ants may move inside in the winter!

This is an excerpt from the UGA publication Argentine Ants by Dan Suiter and Brian Forschler, Department of Entomology

Argentine ant from pub
Argentine ants form strong foraging trails.

To survive the winter, Argentine ants commonly move into protected environments where temperatures are warmer and environmental conditions more stable. In structures, for example, ants commonly move into voids and other elements of construction that provide a warm, stable environment.

As spring temperatures return, Argentine ants move back into their preferred, outdoor nest sites where colonies grow steadily throughout the warm season. In the Southeast, populations typically peak in late summer. By early winter, declining temperatures once again trigger ants to begin searching for protected overwintering sites, and the cycle repeats.

To prevent large, late-season ant populations, and the resulting problems associated with winter infestations, management practices (especially outdoor baiting) should be started in the spring and continued through the warm season.

There are a number of approaches that can be utilized for the treatment of existing Argentine ant infestations, but no single insecticide-based approach is completely effective. An integrated approach, therefore, that incorporates both chemical and nonchemical techniques is best suited for the management of this ant species. If chemical controls are utilized, read and follow all pesticide label instructions, and never do more than what the label permits.

Before chemically-based Argentine ant control measures are undertaken, a thorough inspection of the indoor and outdoor premises should be conducted to determine the extent and origin of the infestation. The inspection should identify those areas where chemical control approaches should be directed.

 

The Argentine Ants publication discusses management techniques used to control these ants.

The Turfgrass Industry is Losing Two Important Products for Weed Management

Patrick McCullough, Associate Professor, UGA

The turfgrass industry is officially losing Illoxan (diclofop-methyl) and Embark (mefluidide) in 2015.  These are two important tools in weed control programs with no comparable replacements.  The loss of these materials has significant implications for resistance management, seedhead control, and efficiently managing high quality turfgrass.

Goosegrass - John D. Byrd, Mississippi State University, Bugwood.org
Goosegrass – John D. Byrd, Mississippi State University, Bugwood.org

Illoxan (diclofop-methyl)

Bayer will not be reregistering Illoxan.  Unfortunately, the return on Illoxan sales was not worth the expenses of reregistration for the company.  Illoxan is a postemergence herbicide used for goosegrass control in bermudagrass golf courses.  This herbicide is one of the most effective chemistries for controlling goosegrass in greens, tees, fairways, and roughs.  More importantly, Illoxan is the only ACCase inhibitor used in bermudagrass turf and the loss of this mechanism of action may have significant consequences for resistance management. Goosegrass resistance to ALS inhibitor herbicides, specifically foramsulfuron (Revolver), is becoming more widespread throughout the Southern U.S.  Turf managers also have restrictions on MSMA use on golf courses that limit the ability to effectively control goosegrass and other weeds.

Illoxan is an excellent herbicide for controlling goosegrass at most growth stages in bermudagrass and also offered an alternative mechanism of action in resistance management programs.  The implications of losing Illoxan in golf course management will emphasize the need for investments in good preemergence herbicides for goosegrass control.  Dinitroanilines (DNAs) like prodiamine (Barricade, others) and pendimethalin (Pendulum, others) have potential to control goosegrass but results are often erratic.  Resistance to DNA herbicides has also developed in goosegrass populations and alternative chemistries may be needed for effective control.  From our research at UGA, Ronstar (oxadiazon) and Specticle (indaziflam) have consistently been the best preemergence herbicides for controlling goosegrass in bermudagrass turf.  Other herbicides such as Dismiss (sulfentrazone), Sureguard (flumioxazin), and Tower (dimethenamid) have potential to control goosegrass but our results have been inconsistent over years.

With the loss of Illoxan, bermudagrass managers will only have Revolver (foramsulfuron), Tribute Total (foramsulfuron + thiencarbazone + halosulfuron) and Dismiss (sulfentrazone) available for postemergence goosegrass control.  While these herbicides may control immature goosegrass, single applications often do not control tillered plants.  Revolver and Tribute Total are both ALS inhibitors and will not effectively control mature goosegrass or resistant biotypes.

Turf managers may also explore the use of MSMA + Sencor (metribuzin) for goosegrass control but these treatments can be very injurious to bermudagrass in summer and may require sequential applications.  Moreover, superintendents in Georgia are limited to one application of MSMA per year, not to exceed 25% of the total golf course.  Turfgrass managers must understand that losing Illoxan may limit their ability to control goosegrass and may have serious repercussions in resistance management programs.

Embark (mefluidide)

Embark is a growth regulator primarily used for annual bluegrass seedhead control in turfgrass management.  Earlier this year there was controversy around the future manufacturing of mefluidide, the active ingredient in Embark, and if this product would be available after 2015. PBI Gordon explored opportunities inside and outside of the U.S. to have mefluidide manufactured and formulated to make new Embark products.  The opportunity to make new material was very costly for the company and PBI Gordon has decided not to pursue this investment.  The Embark 2S product will be pulled completely, and there will be new Embark T & O 0.2L (essentially a dilution of the 2S) released until the current supply is gone.  Once the existing inventory has been sold, Embark will no longer be available from PBI Gordon.

Embark is a growth regulator that has a long history of use in turfgrass and roadside management.  Embark is the only seedhead inhibiting growth regulator available for use in warm and cool-season turfgrasses.  Turfgrass managers primarily use this chemistry for seedhead control on annual bluegrass, tall fescue, bermudagrass, and other turfgrass species.  Proxy (ethephon) is the other seedhead inhibitor available for turfgrass.  It is labeled only for cool-season grasses but may be applied to certain zoysiagrass varieties.  Proxy causes leaf chlorosis, stand thinning, and quality reductions in bermudagrass, seashore paspalum, and other warm-season species.  Other PGRs like Primo (trinexapac-ethyl) or Trimmit (pacloburazol) may provide partial seedhead control but are generally less effective than Embark and Proxy.

Current research efforts at UGA include evaluating seasonal application timing of PGRs to minimize injury and maximize seedhead control on warm-season grasses.  We are also evaluating alternatives to Embark, primarily ALS inhibitor herbicides, for seedhead management in bermudagrass turf.  Embark is the most popular PGR for annual bluegrass seedhead control in bentgrass greens in Georgia and further research will be needed with Proxy, Proxy + Primo, and other compounds to replace Embark.

Patrick McCullough is an associate professor and extension specialist in turf weed science at the University of Georgia in Griffin.

What is this winter weed that shows up every year at this time?

Florida betony plant
Figure 1 – Flower and foliage of Florida betony.

This weed is Florida betony. It is also called rattlesnake weed.

The publication Controlling Florida Betony in the Landscape gives cultural and chemical controls for this weed in lawns and landscape beds. The authors are Mark Czarnota, Ph.D., and Tim Murphy, Ph.D., Weed Control Specialists. Departments of Horticulture and Crop Science

Click here to see the publication for the following information:

Florida betony (Stachys floridana) (also called rattlesnake weed and hedge nettle) is a problem weed in both turfgrasses and ornamentals.

Florida betony tubers
Figure 2 – Tubers of Florida betony that look like the rattle of a rattlesnake, hence the name “rattlesnake weed.”

Florida betony is a “winter” perennial and, like most plants in the mint (Labiatae) family, has a square stem with opposite leaves. Flowers are usually pink and have the classic mint-like structure (Figure 1). Unlike its relatives, it has the unique characteristic of producing tubers that look like the rattles (buttons) of a rattlesnake, hence the name “rattlesnake weed” (Figure 2).

Click here to readthepublicationn Controlling Florida Betony in the Landscape

What are the best post-emergence herbicides for annual bluegrass control in turf?

Annual bluegrass - Robert Vidéki, Doronicum Kft., Bugwood.org
Annual bluegrass – Robert Vidéki, Doronicum Kft., Bugwood.org

Postemergence Annual Bluegrass Control in Turf

Patrick McCullough, Extension Weed Specialist, University of Georgia

Edited from a more complete article which can be found here.

Contrary to its name, both annual (live for one season) and perennial (live for many seasons) populations of annual bluegrass may be found in turf.  Annual bluegrass may out-compete other turf species during late fall and early spring.  Annual bluegrass often dies from summer stresses but may survive if irrigated – especially the perennial biotypes

Postemergence Control (See Table 3)

Annual bluegrass may be selectively controlled with postemergence herbicides (Table 3).

Landscapers managing warm-season grasses have more options for selective postemergence annual bluegrass control than cool-season grasses.

Flazasulfuron (Katana), foramsulfuron (Revolver, Tribute Total), rimsulfuron (TranXit), and trifloxysufluron (Monument) are labeled for bermudagrass and zoyiagrass non-residential commercial lawns and other sites.  Flazasulfuron and rimsulfuron are also labeled for use in centipedegrass. Efficacy of these herbicides generally increases under warm temperatures in spring compared to winter and non-ionic surfactants may enhance efficacy.

Pronamide (Kerb) is a restricted use herbicide for annual bluegrass control in non-residential bermudagrass, centipedegrass, St. Augustinegrass, seashore paspalum, and zoysiagrass.  Pronamide is root-absorbed and must be watered in following applications.  Pronamide efficacy is generally slower than most sulfonylureas and activity for annual bluegrass control may take approximately four to six weeks.

Atrazine (Aatrex, Bonus S, others) and simazine (Princep, WynStar, others) may also be applied to bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass for selective postemergence annual bluegrass control.  These herbicides often provide erratic control of annual bluegrass but may control other grassy and broadleaf weeds.  Actively-growing bermudagrass is sensitive to atrazine and applications are recommended only during the late fall and winter months.

Dormant bermudagrass may be treated with nonselective herbicides, such as glyphosate (Roundup, Touchdown, others), glufosinate (Finale), and diquat (Reward).  These herbicides will injure or kill existing vegetation, including annual bluegrass and managers should only spray at peak dormancy when no green turfgrass foliage is observable.  Nonselective herbicides should only be applied to completely dormant bermudagrass and applications during early spring may delay greenup with significant turf injury.

Flumioxazin (Sureguard) is a new herbicide for pre- and postemergence annual bluegrass control but applications are limited to dormant bermudagrass only.  Flumioxazin use after greenup or on other species are not recommended due to excessive injury potential.

Selective annual bluegrass control options in cool-season lawns are limited.

Ethofumesate (Prograss) controls established annual bluegrass in perennial ryegrass, tall fescue and dormant bermudagrass (see the current edition of the Georgia Pest Management Handbook). Two or three ethofumesate applications may be applied in late fall at three- to four-week intervals. Annual bluegrass control may be seen that fall, but control is usually observed the following spring. Annual bluegrass control with ethofumesate may vary greatly over years depending on environmental conditions.

Amicarbazone (Xonerate) is a new Photosystem II inhibitor, similar to triazine herbicides, but may be used in tall fescue lawns and other cool-season grasses.  Applications of amicarbazone in Georgia are limited to springtime only to minimize injury to cool-season grasses.  Warm-season turf is very tolerant to amicarbazone and may be treated at any seasonal timing.

Bispyribac-sodium (Velocity) has shown potential for selective annual bluegrass control in tall fescue and perennial ryegrass lawns.  However, this herbicide is currently registered for creeping bentgrass and perennial ryegrass on golf courses and sod farms only.  Spot treatments of nonselective herbicides are generally the most effective treatment regimen for annual bluegrass control in cool-season grasses.

Table 3.  Efficacy of postemergence herbicides for annual bluegrass control in turfgrass.

Common NameTrade Name (Examples)Efficacy
amicarbazoneXonerateF-G
atrazineAatrex, othersE
bispyribac-sodiumVelocityF-G
flazasulfuronKatanaG-E
flumioxazinSureguardF-G
foramsulfuronRevolverE
glufosinateFinaleE
glyphosateRoundup, othersE
imazaquinImageP-F
metribuzinSencorG
pronamideKerbE
rimsulfuronTranxitE
simazinePrincep, othersG-E
thiencarbazone + foramsulfuron + halosulfuronTribute TotalG-E
trifloxysulfuronMonumentE

E = Excellent (90 to 100%), G = Good (80 to 89%), F = Fair (70 to 79%), P = Poor (<70%).

For more information

Annual Bluegrass Control in Residential Turfgrass

Annual Bluegrass Control in Non-Residential Commercial Turfgrass

Understanding Formulations Used As Liquid Sprays

From the publication Insecticide Basics for the Pest Management Professional

By Daniel R. Suiter, UGA Department of Entomology & Michael E. Scharf, UFL Department of Entomology and Nematology

 

Formulations commonly applied as liquid sprays are:

  • emulsifiable concentrates (abbreviated as EC)
  • wettable powders (WP)
  • suspension concentrates (SC)
  • microcaps (ME [microencapsulates] and CS [capsule suspensions])

 

These formulations must be diluted with water before they can be applied.

 

Emulsifiables are formulations that allow a water-insoluble insecticide to be suspended in water. Water and oil do not mix unless an emulsifying agent is added. When an emulsifier is added to a mixture of oil and water, microscopic droplets of oil are formed that disperse throughout the water. The resultant milky-white mixture is referred to as an emulsion.

 

Contact insecticides must be hydrophobic (insoluble in water) in order to penetrate the insect cuticle and/or interact with target sites. Although insoluble in water, most insecticides are soluble in oil or another solvent. To form an insecticide-active emulsion, the insecticide is dissolved in the solvent. When the emulsifier is then added, the resulting milky-white emulsion contains microscopic droplets of insecticide-impregnated solvent that become dispersed evenly throughout the water, as described in the previous paragraph. This resultant formulation can then be sprayed.

 

The droplets in emulsifiable formulations do not settle like suspensions and, therefore, require minimal agitation in comparison to formulations that are suspensions (wettable powders, microencapsulates, suspension concentrates).

 

Because emulsifiables readily absorb into skin, appropriate precautions should be used to minimize contact.

WP settling
Several liquid spray formulations (wettable powders, suspension concentrates, and microcapsules) form true suspensions, and will settle out of water when given sufficient time. In these photographs, a suspension concentrate was diluted in water at 4:00 p.m. (top photograph). The following morning, the solid, particulate matter had settled to the bottom of the glass beaker (bottom photograph), and required agitation to re-suspend the product.

Wettable powder formulations are created by impregnating or coating a microscopic particle of an inert carrier (e.g., adsorptive clay, talc, etc.) with insecticide and various inert ingredients to enhance the wetting, spreading, and dispersing characteristics of the powder.

 

The inert ingredients (wetting agents) allow the dry powder to evenly disperse in and mix with water without clumping or caking.

 

Because wettable powders are true suspensions, constant agitation is required to keep the powder suspended in water.

Wettable powders do not readily absorb into skin, but care should be taken when using this formulation to avoid accidental inhalation.

Suspension concentrates can be considered wettable powders that have been packaged in liquid formulation. They consist of very small crystals of technical grade insecticide mixed with an extremely fine, inert dust, a small amount of water, and various other inert ingredients. The inert ingredients enhance the dispersion and mixing characteristics of the formulation when diluted with water.

Because suspension concentrates settle out of suspension, they require constant agitation (Figure 1).

Microencapsulated products are formed by encapsulating an insecticide in a microscopic, round, plastic capsule. The capsules are mixed with inert ingredients (dispersants, wetting agents, etc.) to keep them from clumping and to help the mixture flow more readily. The inert ingredients also facilitate storage and dispersion when diluted in water.

The capsule’s wall thickness determines the release rate of the insecticide to the outside environment. The insecticide seeps through the capsule’s wall and coats the outside of the capsule. As the insecticide disappears (degradation, evaporation, etc.) additional insecticide inside the capsule continues to coat the capsule surface. This process maintains a capsule that is constantly coated with a thin film of insecticide.

The manufacturer can change the characteristics of the capsule wall to slow (or accelerate) the release rate of the chemical from inside the capsule, thus altering the residual life of the treatment. Changing the characteristics of the capsule can alter the product’s odor (slower release rates result in less smell); protect the chemical from environmental degradation; influence the rate of kill by the insecticide (faster release rates mean a faster rate of kill); and reduce exposure to non-target organisms.

Because microcaps settle out of suspension, constant agitation is required.

 

What are the best methods to prevent annual bluegrass in turf?

Pre-emergence Annual Bluegrass Control in Turf

Patrick McCullough, Extension Weed Specialist, University of Georgia

Edited from a more complete article which can be found here.

Annual bluegrass (Poa annua L.) is a problem winter annual weed.  Contrary to its name, both annual (live for one season) and perennial (live for many seasons) populations of annual bluegrass may be found in turf.

Annual bluegrass seed germinates in late summer/early fall once soil temperatures fall below 70° F.  Annual bluegrass may out-compete other turf species during late fall and early spring.  Annual bluegrass often dies from summer stresses but may survive if irrigated – especially the perennial biotypes.

Cultural Control of Annual Bluegrass

Irrigate deeply and infrequently to encourage turfgrass root development and improve the ability of turf to compete with annual bluegrass.  Overwatering, especially in shady areas, may encourage annual bluegrass invasion.

Avoid soil compaction.  Core aerate during active turf growth to encourage quick recovery.  For cool-season grasses, time aerfications before annual bluegrass germinates.

Reduce nitrogen fertilization during peak annual bluegrass germination and periods of vigorous growth.  Fertilizing dormant turfgrasses when annual bluegrass is actively growing may make infestations worse.

Use the proper mowing height, frequency, and equipment for your turfgrass (Table 1).  Raise the turf mowing height during peak annual bluegrass germination.

Mow turfgrass frequently during periods of vigorous growth to prevent scalping.  Returning clippings recycles nutrients to the soil but clippings may need to be removed when annual bluegrass is producing seedheads to reduce the spread of viable seed.

Prevention Using Pre-emergence Herbicides (See Table 2)

Preemergence herbicides may prevent annual bluegrass establishment from seed.  However, preemergence herbicides will not eradicate established plants and will not effectively control perennial biotypes of annual bluegrass from spreading vegetatively.  Application timing of preemergence herbicides for annual bluegrass control is very important.  Herbicides must be applied in late summer/early fall before annual bluegrass germination.  A second application can be applied in winter to control later germinating plants.  Fall applied preemergence herbicides should not be used if reseeding or resodding is needed to repair areas of damaged turf within several months after herbicide applications.

Several preemergence herbicides used for summer annual weed control will effectively control annual bluegrass in fall and winter (Table 2).  Fall applications of herbicides such as bensulide (Betasan), dithiopyr (Dimension), flumioxazin (Sureguard), oxadiazon (Ronstar, Starfighter), pendimethalin (Pendulum, others), and prodiamine (Barricade, others) may effectively control annual bluegrass.  Indaziflam (Specticle) provides excellent preemergence control of annual bluegrass and also provides early-postemergence control as well.  Indaziflam is only labeled in warm-season turfgrasses but may provide greater application timing flexibility than dinitroaniline herbicides in fall.

Combination herbicide products are also available which may improve efficacy of applications.  These products include oxadiazon plus bensulide (Anderson’s Crab and Goose), oxadiazon plus prodiamine (Regalstar), and benefin plus oryzalin (Team 2G or Team Pro).  Many preemergence herbicides are available under a wide variety of trade names and formulations and turf mangers should carefully read label directions before applications.

Atrazine (Aatrex, Purge, others) and simazine (Princep, WynStar, others) are labeled for centipedegrass, zoysiagrass, St. Augustinegrass and bermudagrass.  Atrazine can be applied to actively growing and dormant centipedegrass or St. Augustinegrass but bermudagrass can be injured if treated while actively growing.  Both herbicides have excellent preemergence activity on annual bluegrass but soil residual is generally shorter (four to six weeks) compared to aforementioned herbicides.  Several atrazine products are restricted use pesticides and turf managers should check labels for further information before use.

Mesotrione (Tenacity) is labeled for use in centipedegrass, perennial ryegrass, St. Augustinegrass (sod production only), tall fescue, and dormant bermudagrass (Table 2).  Mesotrione may be applied during establishment of these grasses (except bermudagrass) and effectively controls annual broadleaf and grassy weeds.  Preemergence applications of mesotrione control or suppress annual bluegrass but postemergence use is ineffective for control of established plants.  Mesotrione may be applied in tank-mixtures with atrazine or simazine on centipedegrass to improve efficacy of applications.

Most preemergence herbicides will provide similar initial efficacy if applied before annual bluegrass germination and sufficient rain or irrigation is received.  Preemergence herbicides require incorporation from irrigation or rainfall so that weeds may absorb the applied material.  In order to effectively control annual bluegrass, preemergence herbicides must be concentrated in the soil seedbank.  Retention on leaf tissue can be avoided by irrigating turf immediately after application for effective soil incorporation and herbicide activation.

Preemergence herbicide applications on non-irrigated sites have less potential for residual control, compared to irrigated turf, from product loss, poor soil incorporation, and failure to activate the herbicide.  Practitioners should return clippings on non-irrigated sites to help move potential herbicides remaining on leaf tissue to the soil.  If clippings are collected as part of routine maintenance, practitioners should consider returning clippings until at least half to one inch of rainfall is received.  Granular products may also be applied to non-irrigated sites for better soil incorporation than liquid formulations.  Granular products may be easier to handle and apply with less equipment necessary than sprayable formulations.  Granular herbicides should be applied when morning dew is no longer present to avoid interference from leaf tissue.

Managing Herbicide Resistance

Repeated use of one herbicide chemistry may control annual bluegrass but resistance may develop.  Herbicide resistance is the survival of a segment of the population of weeds following a herbicide dosage lethal to the normal population.  Resistance occurs from repeated use of the same herbicide or mode of action over years and may be a concern with annual bluegrass.

Triazine herbicides, atrazine and simazine, have been repeatedly used for years due to the wide spectrum of weeds controlled as pre- or postemergence treatments in warm-season grasses.  Resistance in weed populations has been reported with these herbicides which may contribute to inconsistent efficacy for annual bluegrass control in turf.  Resistance to sulfonylureas has been reported in numerous weed species and repeated use in turfgrasses may also contribute to resistance in annual bluegrass populations.

Preemergence chemistries, such as the dinitroanalines, (benefin, oryzalin, pendamethalin and prodiamine) may have resistance among weed populations from repeated use over years.  Turf managers should rotate preemergence herbicides from dinitroanilines to other modes of action to minimize resistance in annual bluegrass populations.  Herbicides to consider in rotation programs from dinitroanilines would include indaziflam, ethofumesate, or oxadiazon.  These chemistries offer a different mode of action than dinitroanilines but cost, label restrictions, and turfgrass tolerance may be limiting factors for using these products.  Combination herbicides are also available, such as oxadiazon + prodiamine (Regalstar) and oxadiazon + bensulide (Anderson’s Crab and Goose), with more than one mode of action that effectively control annual bluegrass in turf.

Table 1.  Mowing requirements for commercial turfgrasses.

Mowing Requirements for Turfgrasses
SpeciesMower TypeHeight (inches)Frequency (days)
Bermudagrass
    CommonRotary/reel1 to 25 to 7
    HybridRotary/reel0.5 to 1.53 to 4
CentipedegrassRotary1 to 25 to 10
Perennial RyegrassRotary/reel0.5 to 23 to 7
St. AugustinegrassRotary2 to 35 to 7
Tall FescueRotary35 to 7
ZoysiagrassReel0.5 to 23 to 7

 

Table 2.  Efficacy of preemergence herbicides for annual bluegrass control in commercial turfgrasses.

Common NameTrade Name (Examples)Efficacy
atrazineAatrex, variousE
benefinBalan, othersE
bensulideBetasan, othersF
dithiopyrDimensionG
ethofumesatePrograssG-E
flumioxazinSureguardG
indaziflamSpecticleE
mesotrioneTenacityF
oryzalinSurflan, othersG
oxadiazonRonstar, othersG
pendimethalinPendulum, othersG
prodiamineBarricade, othersE
pronamideKerbE
simazinePrincep, othersE

E = Excellent (90 to 100%), G = Good (80 to 89%), F = Fair (70 to 79%), P = Poor (<70%).

For more information

Annual Bluegrass Control in Residential Turfgrass

Annual Bluegrass Control in Non-Residential Commercial Turfgrass

Fall Management of Large Patch Disease in Turfgrass

Large patch disease - Alfredo Martinez, UGA
Large patch disease – Alfredo Martinez, UGA

Alfredo Martinez, Extension Plant Pathologist

Large patch disease of turfgrass is most common in the fall and in the spring as warm season grasses are entering or leaving dormancy. Large patch is caused by the fungus Rhizoctonia solani. It can affect zoysia grass, centipedegrass, St. Augustinegrass and occasionally bermudagrass.

Symptoms of this lawn disease include irregularly-shaped weak or dead patches that are from 2 feet to up to 10 feet in diameter. Inside the patch, you can easily see brown sunken areas. On the edge of the patch, a bright yellow to orange halo is frequently associated with recently affected leaves and crowns. The fungus attacks the leaf sheaths near the thatch layer of the turfgrass.

Large patch disease is favored by:

  • Thick thatch
  • Excess soil moisture and poor drainage
  • Too much shade which stresses turfgrass and increases moisture on turfgrass leaves and soil
  • Early spring and late fall fertilization.

If large patch was diagnosed earlier, fall is the time to control it with fungicides. Consult the Pest Management Handbook , Turfgrass Pest Control Recommendations for Professionals  or your local Extension Office for fungicide recommendations. Fall fungicide applications may make treating in the spring unnecessary. Always follow label instructions, recommendations, restrictions and proper handling when applying pesticides.

Cultural practices are very important in control. Without improving cultural practices, you may not achieve long term control.

  • Use low to moderate amounts of nitrogen, moderate amounts of phosphorous and moderate to high amounts of potash. Avoid applying nitrogen when the disease is active.
  • Avoid applying N fertilizer before May in Georgia. Early nitrogen applications (March-April) can encourage large patch.
  • Water timely and deeply (after midnight and before 10 AM). Avoid frequent light irrigation. Allow time during the day for the turf to dry before watering again.
  • Prune, thin or remove shrub and tree barriers that contribute to shade and poor air circulation. These can contribute to disease.
  • Reduce thatch if it is more than 1 inch thick.
  • Increase the height of cut.
  • Improve the soil drainage of the turf.
  • Apply lime if soil pH is acidic (i.e. less than 6.0 – except on centipede lawns). Soil pH of more than 6.5 can encourage take all infections.

See the current Georgia Pest Management Handbook for more information. Check fungicide labels for specific instructions, restrictions, special rates, recommendations and proper follow up and handling.

Additional resources:

Turfgrass Diseases in Georgia or Enfermedades de los céspedes en Georgia

Turfgrass Diseases: Quick Reference Guide or Enfermedades de Cespedes Guia de Referencia Rapida

UGA Pest Management Handbook

Turfgrass Pest Control Recommendations for Professionals

When is the best time of year to control fire ants?

Fall is the best time to control fire ants!

Original story by Sarah Lewis, student writer with the UGA College of Agricultural and Environmental Sciences

“April and September are good times to apply baits, once at the start of the season and toward the end to help control before they come back in the spring,” said Will Hudson, a professor with the UGA College of Agricultural and Environmental Sciences.

Fire ants are most active in warm weather. Fire ant season can last 10 to 11 months out of the year in the most southern areas of Georgia. Controlling ant colonies before they produce a mound is important. However, Hudson says that once a treatment program is in effect, timing is not all that important.

Baits and sprays

The general rule of thumb is if the area is one acre or less, don’t use baits. Re-infestation is more likely from colonies outside of the yard when baits are used.

One important thing to remember is the difference between ‘no mounds’ and ‘no ants.’ “There is a difference between eliminating ants and controlling them,” he said. “Baits do not eliminate ants because there is no residual control. A new colony can still come in and be unaffected by the bait laid down prior to their arrival.”

To eliminate mounds completely, apply baits every six months, Hudson said. “There will be invasion in the meantime, and you will still have fire ants, just not enough to create a new mound,” he said.

Hudson recommends treating lawns smaller than an acre with a registered insecticide in a liquid solution. This should rid the lawn of fire ants for one to three months. If you choose a granular product, measure carefully to be sure you apply the correct amount of material and get good, even coverage, he said.

The least effective treatment option for most people is individual mound treatments, according to Hudson. Treating mounds in general is going to be an exercise of frustration, and killing an entire colony by treating just the mound is a challenge, he said.

Minimal impact

Baits are considered to have minimal environmental effects for those who chose not to use hazardous chemicals. Once the bait is out, there is hardly anytime for anything to come in contact with it before the ants get to it.

Nonchemical options include using steam or boiling water. “We recommend using boiling water to treat a mound near an area such as a well where you do not want any chemicals,” Hudson said. “Using hot water is very effective, but the problem is you are not always able to boil the water right next to the area you want treated.” Carrying the boiling water can inflict serious burns, so extreme caution should be used when treating with this method.

There are products on the market that are approved by the Environmental Protection Agency and labeled as organic. Hudson says organic designation is a “slippery” definition. There is an official USDA certification and many states have their own set of regulations when labeling a product as organic. This labeling can mean the product is either a natural product or derived from a natural product. “While there are a few products that qualify as organic, with most baits the actual amount of pesticide applied is minimal,” he said.

Realistic expectations

Hudson says to be careful when choosing a product because the labels can be confusing, even deceptive, and it is difficult to make the right choice. For assistance in selecting a product, contact your local UGA Cooperative Extension agent.

“The most important thing to remember is that you need to be realistic in your expectations,” Hudson said. “If you are treating mounds, you need to be prepared. You are going to chase the mounds around the yard.”

For more information on selecting a control measure:

Find pesticide recommendations in the UGA Pest Management Handbook

Fire Ant Control Materials

Managing Imported Fire Ants in Urban Areas

Fall is the best time to treat for fire ants

 

Tawny Crazy Ant found in three new locations

TAWNY CRAZY ANT

Daniel R. Suiter, Department of Entomology, University of Georgia, Griffin, GA

Tawny crazy ant worker. Photo by Danny McDonald. Click on the image to view the major identifying characteristics. Image from Texas A&M publication found at http://urbanentomology.tamu.edu/ants/rasberry.html
Tawny crazy ant worker. Photo by Danny McDonald. Click on the image to view the major identifying characteristics. Image from Texas A&M publication found at http://urbanentomology.tamu.edu/ants/rasberry.html

Discovery.

In August 2013 James Morgan (UGA Extension Agent in Albany, GA) was the first to find the tawny crazy ant, Nylanderia fulva, in Georgia. Read the story here. Until Morgan’s find, the tawny crazy ant was known from sporadic counties in Mississippi and Louisiana, but was widely-distributed in Texas and Florida.

The tawny crazy ant was formerly known as:

  • The Rasberry crazy ant (after a pest control operator, Mr. Tom Rasberry, the discoverer of N fulva in Texas)
  • The hairy crazy ant (under a microscope the ant appears hairy) and
  • The Caribbean crazy ant (given its FL distribution)

The tawny crazy ant is an invasive ant species from South America with widespread distribution in Texas and Florida. The tawny crazy ant’s biology and general, visual appearance, to the untrained eye, is similar to that of another South American invasive ant species common in Georgia, the Argentine ant (Linepithema humile) (known to Georgians as “sugar ants”). While the tawny crazy ant was detected in Georgia in 2013, the Argentine ant has been established in Georgia for more than 100 years. Neither are native to Georgia.

Trends.

In August 2014 three additional tawny crazy ant sites were brought to our attention by Jarrell Jarret, Arrow Exterminators in Brunswick, GA in conjunction with Don Gardner, UGA Extension Agent. Two sites were found at I-95, exit 26 (Waverly, GA). Neither site was more than a quarter mile from the interstate (one east and one west of I-95). Both sites are in Camden county.

We suspect ants were transported from Florida. A fourth site was found just 3 miles north on I-95, at a gas station (exit 29). This site is in Glynn county.

We suggest that UGA Extension Agents and Pest Control Operators on Georgia’s coast, in southeast Georgia, and in the southern half of Georgia should be on alert for the existence of this major nuisance ant pest. In areas of Texas where the tawny crazy ant has appeared, it has become a tremendous nuisance. Although unseen, and perhaps less appreciated by homeowners, invasive species, including ants, can be highly disruptive to native habitats. Invasive ants commonly drive native ant species to extinction, and can disrupt the “balance” of native ecosystems, resulting in a cascade of detrimental impacts on a system’s ecology.

Control.

Control of the tawny crazy ant is similar to control of the Argentine ant, and includes (primarily) the direct application (strictly by label) of fipronil, pyrethroids, or other labeled sprays to trailing ants and nest sites (concentrations of workers, brood, and queens) around structures. Secondarily, baits can be utilized, but due to colony size and distribution, baits are less effective than perimeter sprays at alleviating this pest’s nuisance status.

The movement of tawny crazy ants into un-infested areas is aided by human beings (potted plants and other personal belongings). tawny crazy ant colonies reproduce by budding. tawny crazy ants do not have nuptial flights, so cannot move long distances unless their movement is aided by humans.

Because the tawny crazy ant is commonly found nesting in and amongst human debris and trash, it is important, in conjunction with chemical treatments, to maintain a tidy property. If this entails maintaining and cleaning-up the outside environment in an area where the tawny crazy ant already exists, it is critically important to not exacerbate the problem by moving the ant to an un-infested site in infested debris in an attempt to tidy the property.

Report Findings of the tawny crazy ant.

Should Pest Control Operators (PCO) or UGA Extension Agents find what they think to be a tawny crazy ant infestation, it is important to send a physical sample for confirmation of their identification. Send physical samples to Dr. Dan Suiter, UGA Griffin Campus, Department of Entomology, 1109 Experiment Street, Griffin, GA 30223. Call Dr. Suiter at 770-233-6114 or email him.

Local Extension Offices can often help PCOs identify insects or ship samples for diagnosis. Find your local Extension Office here or call (800) ASK-UGA1 from any non-cell phone.

Identification.

See this tawny crazy ant Identification Information from Texas A&M. This website includes a video of the tawny crazy ant in a lawn. There is another similar video of tawny crazy ant in leaves.

Reference.

Tawny Crazy Ant page from the Mississippi Entomological Museum website.