Landscape Alerts & Updates

The Landscape Alert is an email newsletter sent to the Georgia landscape and turf industry providing UGA information regarding industry issues.

These issues include emerging pests, regulatory changes, upcoming training, and new information, or technologies for the industry. Coordinated by the Center, the newsletter is a collaboration of several UGA departments – Horticulture, Entomology, Plant Pathology, Crop and Soil Science, and the Warnell School of Forestry.

Readers use the information contained in the Alerts for staff training, remaining current on upcoming issues, scouting for and identifying pests, evaluating current pest control practices and improving workplace safety. Alerts help maintain communications between state and county Extension staff, researchers, the industry, and industry associations. Alerts also serve as an educational tool for County Extension Agents.

Landscape Alerts are currently sent to more than 1700 readers and feedback has been very good. In a recent survey, of those responding, 93% stated they learned something they plan to use.

For more information email ghuber@uga.edu.


 

Latest Landscape Alerts

A New Exotic Tick is Headed to Georgia

by Nancy C. Hinkle, Ph.D.
Dept. of Entomology, Univ. of Georgia, Athens

Anyone who has lived in Georgia probably has experienced ticks, either on themselves or on their pets. The most common of the state’s 22 native tick species is the lone star tick. The American dog tick is the next most frequently encountered tick; even though it is called a dog tick, it can be found on mid-sized wildlife of all types – coyotes, foxes, raccoons, opossums, etc. Gulf Coast ticks seem to be increasing in prevalence and expanding their range. Deer ticks are not very common (the ticks typically found on deer are lone star ticks).

But there is a chance that we’ll be getting a new type of tick – as if we needed it. Last year a tick species that had never been found in North America showed up on a farm in New Jersey. Despite control efforts and a harsh winter, it successfully overwintered and in 2018 has already been found in Virginia, West Virginia, Arkansas, and North Carolina. Its mode of distribution is unknown, but this rapid spread bodes poorly for containment.

Originally from northeast Asia, this tick showed up in Australia and New Zealand over 100 years ago, where it has established and become a significant problem on cattle and sheep. Known as the “Longhorned Tick” (scientific name Haemaphysalis longicornis), it is capable of transmitting several disease organisms infecting livestock and humans.

Why is this tick of particular concern?

  1. It is not native to North America. That means there are no natural controls here to keep it in check – no predators or parasites to suppress its numbers. Also, our animals have not developed any natural resistance to it, so it is anticipated to thrive on both wildlife and livestock.
  2. Males are extraneous. This tick is parthenogenetic, meaning females reproduce without mating, so males are unnecessary. Of course, this means that a single female transmitted into a new area can start a new population, indicating that infestations can readily spread. And each female produces over 2,000 eggs, so populations can rapidly explode.
  3. Longhorned Ticks do well on a variety of hosts, wildlife as well as livestock. They should thrive on white-tailed deer and quickly spread to livestock. They readily feed on small ruminants, horses, dogs, cats, humans, and several common wildlife species.
  4. This tick is tolerant of a wide range of environmental conditions, but will flourish in the Southeast, which has climate similar to its native range. As has been shown, it successfully overwinters in New Jersey, Virginia and West Virginia, so may well be active year-round in Georgia.
  5. The Longhorned Tick is capable of transmitting several animal and human pathogens. Large numbers of ticks feeding on an animal can produce anemia, particularly in young animals.

Unfortunately this invader looks like many of our native ticks, small and brown before it feeds, then swollen and gray after it takes a blood meal. So what should Georgians be looking for to alert them to the Longhorned Tick? High numbers of ticks per animal. Because each tick can produce over 2,000 eggs, tick populations expand rapidly and frequently exceed hundreds per animal. If you find an animal with lots of ticks on it, pull off at least a dozen, put them in a small bottle with alcohol, and take them to your county Extension office. Tell them to send them to Dr. Hinkle in Athens and we will identify them for you (be sure to include your contact information). Then treat the animals to kill the remaining ticks (consult the Georgia Pest Management Handbook for recommendations on tick control).

We may not see Longhorned Ticks in Georgia any time soon, but we do not want to miss them if they do show up.

2018 Tropical Storm Alberto

Guest Post Written by Pam Knox,

Long-time residents of Georgia may remember the devastating floods of Tropical Storm Alberto in July 1994. The rain was so intense that Georgia’s one-day rainfall record was set during that storm, with 21.10 inches recorded at Americus for a 24-hour period ending on July 6, 1994, as the storm stalled over the state. In spite of that incredible record and the resulting damage, the National Hurricane Center did not retire the name of Alberto. This year, Alberto is the first name on the list of Atlantic tropical storm names for the season which begins on June 1.

The latest 5-day outlook for the Atlantic tropical region from the National Hurricane Center indicates that there is an 80% chance of this year’s Tropical Storm Alberto to develop in the Gulf of Mexico in the next five days, even before the season officially begins. While it is not likely to bring extreme winds and storm surge to the area, it is expected to bring copious rain to an area that has already received up to six times as much rain as usual in the last week, covering most of Georgia except the northwest corner. Another six inches is expected across a wide area of Georgia in the next seven days from the slowly moving storm. While this is not likely to be as wet as the 1994 TS Alberto, the wind and rainfall are still going to cause tremendous problems for us here in Georgia, along the coast and inland across most of the state.

Now is the time to think about what you need to do to get ready for the rain, whether or not it organizes enough to be designated as a named tropical storm. If you have weekend activities planned along the Gulf Coast for this Memorial Day weekend, be prepared for intermittent heavy rains, gusty winds, high waves and rip currents in the water along the coast from New Orleans to the west coast of Florida. If you are inland, prepare for localized flooding which will be worse because the ground is already saturated in many areas. Move equipment and livestock out of low-lying areas. Expect some trees to fall because of the wet soil conditions, even if the winds are not that strong. This may mean blockage of roads or disruptions in power, so check your generators now if you need supplemental electricity for your operations. If water covers the road, do as the National Weather Service recommends and “Turn Around, Don’t Drown.” You won’t be able to tell if the road has been undercut or washed away, and water has a tremendous potential to move cars and trucks even when only a few inches deep. The Extension Disaster Education Network (EDEN) has several useful publications on preparation and recovery at https://eden.lsu.edu/educate/resources.

I have heard from a number of contacts that the rain and cloudy conditions over the past two weeks has caused a lot of problems for producers, leading to splitting blueberries, increased fungal diseases, slow growth of crops, and the inability to get into the field to do side dressing of corn, application of fungicides and other treatments, and planting. Unfortunately, I don’t see a shift in this current pattern, and above average rainfall is likely to continue for the next several weeks, although there will be some drier periods that may allow you to get work done.

For updated information follow @SE_AgClimate or on Facebook at SEAgClimate. An excellent source of updated weather information is the local National Weather Service office, but you can also get information from many commercial vendors and the National Hurricane Center. Do not count on your smartphone weather apps to give you the most current information, since many of them are only updated once or twice a day. Keep monitoring for changing conditions, since above average sea surface temperatures in the Gulf of Mexico could lead to a rapid drop in pressure and increase in winds as the center of the storm gets closer to land, or the storm could move in a different direction under weak steering currents.

If you have comments to share about how the current rainy and cloudy weather is affecting your work and your crops, please feel free to send them to me at pknox@uga.edu. I always like to hear how the weather and climate are affecting Georgia agriculture.

Pam Knox
Interim Director, Georgia Weather Network
Crop and Soil Sciences, CAES

Pest Alert: February Monitoring for Granulate Ambrosia Beetle

Post authored by Paul J. Pugliesea and Shimat V. Josephb

aUGA County Extension Agent/Coordinator (Bartow County), Cartersville, GA
bAssistant professor, Department of Entomology, University of Georgia – Griffin Campus.

Fig. 1 Adult beetle (left) and “tooth pick” symptom (right)

Granulate ambrosia beetleXylosandrus crassiusculus (Mot.) [Previously known as the Asian ambrosia beetle]

Introduction: Granulate ambrosia beetle (Fig. 1) is a serious pest of woody trees and shrubs in Georgia. These tiny beetles were first detected in South Carolina in the 1970’s and have spread across the southeastern US.

Host plants: Woody ornamental nursery plants and fruit trees are commonly affected. In spring or even in late winter (around mid-February), a large number of beetles can emerge and attack tree species, especially when they are young. Some highly susceptible tree species include Styrax, dogwood, redbud, maple, ornamental cherry, Japanese maple, crepe myrtle, pecan, peach, plum, persimmon, golden rain tree, sweet gum, Shumard oak, Chinese elm, magnolia, fig, and azalea.

Biology: The female beetles land on the bark of woody trees. Then, they bore through the soft wood and vascular tissues (xylem vessels and phloem) of the tree. They settle in the heartwood and begin making galleries. Eggs are laid in these galleries. Adults introduce a symbiotic fungi into the galleries as a food source for the developing larvae.

Symptoms: The initial sign of infestation is presence of boring dust pushing out of the bark as “tooth picks” (Fig. 1). Severely infested trees with granulate ambrosia beetle may show symptoms of stunting, delayed leaf emergence in spring, and extensive defoliation.

Fig. 2 Timing is a key factor in effectively managing Granulate ambrosia beetle. Monitoring traps placed in early February are useful for the early detection of beetle emergence and infestation.

Monitoring and management: Once adults of granulate ambrosia beetle bore through the bark, there are limited control options to mitigate the problem. Those settled beetles in the heartwood of the tree are less likely to be exposed to insecticides. Also, the beetles do not consume the wood, which further minimizes their pesticide exposure. Pyrethroid insecticides such as bifenthrin or permethrin can be used as preventative sprays to repel invading females. Thus, the insecticide-application timing becomes critically important for management. The insecticide applications can be timed with trap captures or adult activity. The simplest method to determine adult activity in the area is using alcohol and a bolt of wood (Fig. 2). A wood bolt (about 2 to 4-inches in diameter and 2-feet long) can be utilized. Any hardwood species such as maple will work for building traps. A half-inch diameter hole drilled at the center of the bolt, about a foot deep, is filled with alcohol and the opening can be closed using a stopper cork.  Ethyl alcohol or grain alcohol with 95-percent alcohol content (190-proof) can be found at most liquor stores. Hang several bolt traps along the woodland border of a nursery at waist height to determine beetle emergence and activity. Sawdust tooth picks (Fig. 2) begin to appear on the bolt when they are infested with adult beetles. Once tooth picks are detected on a bolt trap, daily scouting should occur on nearby trees.

An immediate spray using a pyrethroid insecticide on nursery trees is warranted upon detection of tooth picks on the bolt trap.  Be prepared and ready to act quickly as soon as beetle activity is confirmed.  If practical, the entire nursery should initially be treated with an area-wide application to repel beetle activity.  If individual trees are found to be infested, immediately destroy infested trees and follow up with targeted spray applications in blocks with beetle activity. Generally, pyrethroids are not effective for more than a week as their residues quickly breakdown. Re-application of the insecticide is generally required at weekly intervals until spring green-up is complete in areas where the beetle pressure is moderate to severe.

Healthy trees can withstand a low level of beetle infestation. Timely irrigation and adequate fertilization of trees throughout the growing season will increase a tree’s tolerance to beetle infestation.  Closely monitor traps throughout the spring for a second emergence of ambrosia beetles. Ambrosia beetles can have multiple generations throughout the year and are strongly attracted to trees that are drought stressed, injured, or excessively pruned.  Pay close attention to irrigation needs during extended summer and fall drought periods to minimize tree stresses.  Avoid mechanical wounding of trees with maintenance equipment that could invite ambrosia beetles to attack.    

When to deploy monitoring traps: The monitoring traps should be deployed starting the first week of February in Georgia because warmer periods during a mild winter may trigger early beetle emergence and infestation.

References: 

  1. Frank, and S. Bambara. 2009. The granulate (Asian) ambrosia beetle. Ornamental and turf. Insect note. North Carolina State University.
  2. Wells. 2015. Managing ambrosia beetles. UGA pecan extension

Landscape Alert – September 2017

Fall Turfgrass Disease Prevention and Control  

by Alfredo Martinez

Large Patch

Rhizoctonia large patch is the most common and severe disease of warm season grasses (bermudagrass, centipedegrass, seashore paspalum, St. Augustinegrass, and zoysiagrass) across the state of Georgia. Due to spring and fall disease-promoting environmental conditions across Georgia coinciding with grasses leaving and/or entering dormancy, large patch can appear in warm season grasses in various grass-growing settings, including home lawns, landscapes, sports fields, golf courses, and sod farms. 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.

photo of turfgrass disease large patch

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 Nitrogen fertilization.

If large patch was diagnosed earlier, fall is the time to control it. There is a myriad of fungicides that can help to control the disease. Fungicides in the following classes are labeled for large patch control: carboxamides, benzimidazoles, carbamates, dicarboximides, DMI fungicides, di-nitro anilines, control. For a complete and updated list of fungicides available for commercial control of large patch, visit http://extension.uga.edu/publications/detail.cfm?number=SB28  or http://www.commodities.caes.uga.edu/turfgrass/georgiaturf/Publicat/1640_ Recommendations.html.  Preventative or curatives (depending on the particular situation) rates of fungicides in late September or early October and repeating the application 28 days later are effective for control of large patch during fall. Fall applications may make treating in the spring unnecessary. Always follow label instructions, recommendations, restrictions and proper handling.

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. Reduced mowing heights result in a more dense turf stand, which may create a more favorable environment for large patch development
  • Improve the soil drainage of the turf.
  • Control traffic patterns to prevent severe compaction, and core aerate to improve soil drainage and increase air circulation around the shoots and root

For more information on large patch visit https://secure.caes.uga.edu/extension/publications/files/pdf/C%201088_2.PDF

  

Spring Dead Spot of Bermudagrass

Fall cultural practices and fungicide applications are key for Spring Dead Spot management. The disease is caused by fungi in the genus Ophiosphaerella (O. korrae, O. herpotricha and O. narmari). These fungi infect roots in the fall predisposing the turf to winter kill.  As indicated by its name, initial symptoms of spring dead spot are noticeable in the spring, when turf resumes growth from its normal winter dormancy.  As the turf ‘greens-up,’ circular patches of turf appear to remain dormant, roots, rhizomes and stolons are sparse and dark-colored (necrotic).  No growth is observed within the patches.  Recovery from the disease is very slow. The turf in affected patches is often dead; therefore, recovery occurs by spread of stolons inward into the patch.  The causal agents of SDS are most active during cool and moist conditions in autumn and spring. Appearance of symptoms is correlated to freezing temperatures and periods of pathogen activity. Additionally, grass mortality can occur quickly after entering dormancy or may increase gradually during the course of the winter. Spring dead spot is typically more damaging on intensively managed turfgrass swards (such as bermudagrass greens) compared to low maintenance areas.

photo of turfgrass disease spring dead spot

  • Practices that increase the cold hardiness of bermudagrass generally reduce the incidence of spring dead spot. Severity of the disease is increased by late-season applications of nitrogen during the previous fall.
  • Management strategies that increase bermudagrass cold tolerance such as applications of potassium in the fall prior to dormancy are thought to aid in the management of the disease. However, researchers have found that fall applications of potassium at high rates actually increased spring dead spot incidence. Therefore, application of excessive amounts of potassium or other nutrients, beyond what is required for optimal bermudagrass growth, is not recommended.
  • Excessive thatch favors the development of the disease. Therefore, thatch management is important for disease control,
  •  Implement regular dethatching and aerification activities.
  • There are several fungicide labeled for spring dead spot control.
  • Timing, selection and application of fungicides are important for preventative management of SDS. Fungicide application in the fall when soil temperatures are between 60° and 80° F provides the best control of SDS
  • A complete list of fungicides, formulations and product updates for SDS can be found in the annual Georgia Pest Management Handbook and the Turfgrass Pest Control Recommendations for Professionals (http://www.georgiaturf.com). Some fungicide options are exclusively for golf course settings. Always check fungicide labels for specific instructions, restrictions, special rates, recommendations, follow-up applications and proper handling.

For more information on SDS visit https://secure.caes.uga.edu/extension/publications/files/pdf/C%201012_3.PDF

 

Early detection of bermudagrass leaf spot 

Severe leaf and crown rot, caused by Bipolaris ssp. can occur in bermudagrass lawns, sport fields, or golf fairways. Initial symptoms of this disease include brown to tan lesions on leaves.  The lesions usually develop in late September or early October.  Older leaves are most seriously affected.  Under wet, overcast conditions, the fungus will begin to attack leaf sheaths, stolons and roots resulting in a dramatic loss of turf.  Shade, poor drainage, reduced air circulation; high nitrogen fertility and low potassium levels favor the disease. To achieve acceptable control of leaf and crown rot, early detection (during the leaf spot stage) is a crucial.

Photo of turfgrass disease Bermudagrass Leaf SpotPhoto 2 of turfgrass disease Bermudagrass Leaf Spot

Dollar spot is still active in the fall/early winter

Dollar spot is most prevalent during spring and fall with infections developing rapidly at temperatures between 60 and 75 degrees Fahrenheit combined with long periods of leaf wetness from dew, rain, or irrigation.

  • Excessive moisture on turfgrass foliage will promote dollar spot epidemics. Irrigating in the late afternoon or evening should be avoided, as this prolongs periods of leaf wetness.
  • If feasible, prune or remove trees and shrubs to promote air movement and accelerate drying of the turfgrass canopy
  • A variety of fungicides are available to professional turfgrass managers for dollar spot control including fungicides containing benzimidazoles, demethylation inhibitors
    (DMI), carboximides, dicarboximides, dithiocarbamates, nitriles and dinitro-aniline. Several biological fungicides are now labeled for dollar spot control.
  • For a complete and updated list of fungicides available for dollar spot, visit http://extension.uga.edu/publications/detail.cfm?number=SB28 or http://www.commodities.caes.uga.edu/turfgrass/georgiaturf/Publicat/1640_Recommendations.htm.

photo: turfgrass disease dollar spot photo: turfgrass disease dollar spot2

Additional information on dollar spot visit https://secure.caes.uga.edu/extension/publications/files/pdf/C%201091_2.PDF

Landscape Alerts and Updates – MAY 2017

Slime Mold on Turfgrasses

Has your lawn been slimed?  Fear not, the grayish-black sooty substance on your turfgrass is a harmless soil protozoa that has temporarily migrated onto blades and stems to produce and disperse spores.  Diagnosis: Slime Mold,  Physarum and Fuligo sp./spp.  The occurrence is prompted by spells of humid, rainy weather during spring and early summer and is typically short-lived (1-2 weeks).  Aside from temporarily hindering photosynthesis, slime molds do not parasitize or damage the turfgrass.   Slime mold can be ignored, mowed, raked, or washed off with a pressurized stream of water.

Related Articles: what-is-this-unusual-growth-on-lawns


Lawn Burweed

If you missed the window of opportunity to manage burweed in your lawn in late winter/early spring, then you may be feeling it, literally!  The seed burs are now mature and a barefoot stroll across the lawn may inflict you with some painful hitchhikers.  At this point, applying a broadleaf herbicide product may kill the weed, but will not eliminate the existing burs that have formed, so mark your calendars for burweed scouting and control next February.  If an immediate solution is needed, locate individual plants and physically remove them.  Burweed tends to colonize compacted bare areas. For large areas of infestation it may be necessary to scalp and bag the clippings with a mower to remove the burs, followed by turfgrass renovation or establishment on those areas (assuming that you have a warm-season turfgrass species such as bermudagrass, it would not be advisable to scalp a Tall Fescue lawn in May).  For more information on scouting for lawn burweed, refer to the previous post “Winter Scouting for Lawn Burweed.”

Related articles: winter-scouting-for-burweed-soliva-pterosperma


Turf Aerification

Now is the time to aerify warm-season turfgrasses.  Last year, the dry conditions persisting from August through December depleted carbohydrate reserves in warm-season turfgrasses. A delay in turfgrass green-up was common this spring and warm-season turfgrasses are poised to replenish carbohydrate reserves and restore root systems.  “If there is a year to seriously consider core aerification, this is it,” says Dr. Clint Waltz, a Cooperative Extension turfgrass specialist with the University of Georgia College of Agricultural and Environmental Sciences.  Core aerification relieves compaction, improves air exchange and water infiltration, and stimulates deeper root growth.  Hollow-tine aerification is the preferred method, removing soil cores to a depth of 3-4 inches, and having longer-lasting benefits.  A light fertilizer application in concert with aerification can be beneficial, but heavy nitrogen applications should be avoided to allow for the replenishment of carbohydrate reserves (over-stimulating top growth depletes carbohydrates reserves).

To make sure soil pH, phosphorus and potassium levels are within recommended ranges for optimum growth, take a soil sample to your local University of Georgia Cooperative Extension office.

Read the full article on Core Aerification and find lawn care calendars for different turfgrass species at www.GeorgiaTurf.com .

Related Articles and Publications:

Turfgrass Fertility: Soil Texture, Organic Matter, Aeration, and pH (C 1058-1)


 

 

Landscape Alerts share info from UGA Extension on issues of interest to the commercial landscape industry.

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