Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, Dave Goerig, Dan Herms, Tim Malinich, Jane Martin, Pam Sherratt, Amy Stone, and Curtis Young
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August 05, 2004
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This is the Eighteenth 2004 edition of the Buckeye Yard and Garden Line (BYGL).
BYGL is developed from a Tuesday morning conference call of Extension
agents, specialists and other contributors in Ohio.
BYGL is also made available on the Internet from the Ohio State University
Horticulture and Crop Science (HCS) in Virtual Perspective website
(http://bygl.osu.edu). Additional fact sheet information on any of
these articles may be found through the OSU fact sheet database (http://plantfacts.osu.edu).
BYGL is a service of OSU Extension and is aided by major support
from the Ohio Nursery and Landscape Association (ONLA), with additional
funding from the Ohio Chapter of the International Society of Arboriculture
(ISA) to the OSU Extension Nursery Landscape, and Turf Team (ENLTT).
Participants in the August 03, 2004 conference included: Pam Bennett (Clark); Barb Bloetscher (C. Wayne Ellett Plant and Pest Diagnostic Clinic); Joe Boggs (Hamilton/South District); Erik Draper (Geauga); Tim Malinich (Cuyahoga); Joe Rimelspach (HCS); Dave Shetlar (Entomology); Amy Stone (Lucas); Curtis Young (Allen County); and Randy Zondag (Lake).
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Additional factsheet information on any of these articles may be found
through the OSU Factsheet Database (http://plantfacts.ohio-state.edu/)
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WEATHER WATCH
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Starting in the south, Shawn Wright reported that 3/4" of rain fell over the weekend and a new record minimum on July 29 was recorded (57.2F) in the Piketon area. Joe Boggs shared the following weather highlights from the Greater Cincinnati area: July's precipitation totaled 6.14", +2.39" when compared to the monthly average; and 29.19" of precipitation has fallen in 2004, +2.66" when compared to the year-to-date average. Joe also mentioned that last week was dominated by cool temperatures in Cincinnati, with two days having record low, high temperatures (66F). This enhanced the effects of the rainfall received last week, causing lawns to become green and grow at rates usually experienced in the spring and fall.
Tim Malinch's account of the western Cleveland weather included storms dropping 1.5" (and more) of rain on the area depending upon where you lived. Places once soaked, are becoming high and dry because of the lack of additional rainfall. Amy Stone reported that the Toledo area continues to lag behind in precipitation. For the year, 16.23" of precipitation fell in Lucas County, compared to the year-to-date total of 19.75".
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HORT SHORTS
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JAPANESE BEETLE OBSERVATIONS
Pam Bennett reported that Japanese beetle (JB) populations are quite heavy in the Gateway Learning Gardens at the Clark County Extension office. In addition, population levels are quite variable across the county; BYGLers agreed that they were also variable across the state. Pam also noted preferential beetle feeding among the roses in these display gardens.
A floribunda rose, 'Betty Pryor', was completely stripped, leaving only the stems and mid-veins of the plant and an old-fashioned rose, "Baronne Prevost", was almost completely striped. An old unnamed variety had severe feeding injury but not as much as 'Betty Pryor'. Rosa rugosa had very little feeding damage on the foliage and the 'Knockout' rose sustained feeding damage only on the new growth.
While these observations are purely anecdotal, recent research at the University of Kentucky suggests that JB do have a preference for certain roses. According to research by Dan Potter and David Held, UK Entomology, JB's arrive at different rates based upon floral characteristics like color and fragrance. It suggested that the presence of floral display, or fragrance, greatly influences rose susceptibility to JB. In trials where flowers were removed, there was very little damage. In addition, once a plant is damaged it becomes more attractive to beetles.
With that being said and not wanting to sacrifice the display roses to further the frontiers of science, Pam sprayed the plants with bifenthrin - knocking those pesky JB's right off the plants!
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BLACK BOTTOMS TOP TOMATO WOES
BYGLers continue to receive telephone calls about tomatoes, including this week's common woe- BLOSSOM END ROT. In addition to tomatoes, this disorder is also seen on peppers and eggplants. Distressed gardeners are noticing dry sunken decay that has developed on the blossom end (opposite the stem) of many fruit.
On tomatoes and eggplants, blossom-end rot usually begins as a small water-soaked area at the blossom end of the fruit. While this is likely to begin to appear while the fruit is green or during ripening, it is only when the lesion expands, becomes sunken, and turns black and leathery that many gardeners notice the problem. In severe cases, it may completely cover the lower half of the fruit, becoming flat or concave. Secondary pathogens commonly invade the lesion, often resulting in complete destruction of the infected fruit. On peppers, the affected area appears tan and is sometimes mistaken for sun scald, which is white. Secondary molds often colonize the affected area, resulting in a dark brown or black appearance. Blossom-end rot can also occur on the sides or shoulders of the pepper fruit close to the blossom end.
Blossom-end rot is NOT caused by a parasitic organism, but is a physiologic disorder associated with a low concentration of calcium in the fruit. Calcium is required in relatively large concentrations for normal cell growth. When a rapidly growing fruit is deprived of necessary calcium, the tissues break down, leaving the characteristic dry, sunken lesion at the blossom end. Blossom-end rot is induced when demand for calcium exceeds supply. This may result from low calcium levels or high amounts of competitive cations in the soil, drought stress, or excessive soil moisture fluctuations which reduce uptake and movement of calcium into the plant, or rapid, vegetative growth due to excessive nitrogen fertilization.
For a complete list recommendations, check out the Home Yard and Garden FactSheet, #3117, "Blossom End Rot of Tomatoes, Peppers, and Eggplants." Maintaining a soil pH of 6.5 and avoiding drought stress and wide fluctuations in soil moisture can help. Foliar applications of calcium, which are often advocated, are of little value because of poor absorption and movement to fruit where it is needed.
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BUG BYTES
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SPIDER TALES
Once again, stories of Brown Recluse (BR) spider "bites" inciting sores and necrotic ulcers on people have crept across newspapers and television news. Unfortunately though, these claims were based on supposition of what people assumed were recluse bites instead of via informed analyses. In fact, in many states where BR dont thrive, doctor and layman declarations of brown recluse bites far outnumber the known populations of BR spiders in that state. In a study where BR are endemic, researchers caught an average of 30-45 BR spiders per house (one had over 2000!), yet not one person was bitten in the 4-7 years of the study while people lived in the houses.
Brown recluses are small (3/8"), tan-beige, smooth spiders with relatively long legs and a violin shaped dark design on the cephalothorax. Although immature recluses and some individuals may not have the "violin", they can be positively identified by the 3 pairs of eyes arranged above the mouthparts. Since many spiders are commonly confused with brown recluses, "suspicious" spiders should be inserted intact (if possible) in a bottle of alcohol, and submitted to the C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC) for verification.
As their name suggests, brown recluse spiders hide in dark, secluded corners, in or near grayish cobwebs. They rarely venture far from the web, and may exist in a house for years without the homeowner even noticing them. Indigenous to Central South and Midwest United States, they are often transferred to surrounding states as they hide in boxes and clothes. In their natural habitat, recluses can live outdoors under firewood, shacks or piles of material, but in the northern states, they are only found inside heated buildings. Because of their natural tendency to hide, people who claim to be bitten by a BR in their yard were probably bitten by another spider or insect, or possibly stung or scratched by an irritating plant.
Normally, BR bites are not noticed until the skin begins to burn and redden. A hardened, white blister forms in the center and the skin around the sore continues to decline. People who are sensitive to spider bites may experience nausea, malaise and fever. If the bite becomes infected, redness and sloughing skin may expand to 2". When a person suspects that he/she was bitten, the spider, even if smashed should be collected and identified. Even if the spider is not found, wounds suspected to be bites should be washed immediately and covered with a clean bandage.
Regardless of the spider or other offenders, jagged wounds often become seriously infected. If the wound continues to fester after a day or two, consult a dermatologist. An experienced doctor will recommend that the lesion be soaked with hydrogen peroxide, iodine or Burrows solution, and prescribe a corticosterioid (eg. prednisone, phemtolamine), and an antibiotic to prevent bacterial infection. Be aware that other problems such as Lyme disease, diabetic ulceration or a chemical burn can mimic spider bites, and if not treated correctly, can become serious.
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"B-52" HORSE FLIES
Several BYGLers reported receiving complaints about large populations of big horse flies. These flies seem to be everywhere, not just out in the country near livestock facilities. They are also putting a fright into small children and some adults as they bang clumsily around buildings and cars. They do have a bit of a frightful appearance to them with their big bulging, often brightly colored eyes and large, hard, sharp-looking mouth parts hanging under their heads. Because of the size of some species, one can see them coming from a distance which can be distracting while driving down the highway with them flying directly toward and pinging off of the windshield. Curtis Young mentioned that they do not appear to be the smartest critter in the world either. He has seen them chase after cars, land on the tires and try to bite them in search of a blood meal. So the questions are why so many, and why do they chase cars?
The large number of horse flies is not because of the wetter-than-normal spring and summer that we have been having this year, but because of the wetter-than-normal conditions from last year and previous years. Horse fly larvae, and their cousins the deer flies, live in ponds, streams and marshy areas where their feed as predators of other insects for one to several years depending on the species. When they are ready to pupate, they move from the water to terrestrial sites. Adults of a particular species generally emerge synchronously, thus the appearance of numerous flies all at the same time. If several species exist in the same area, a glut of one species may be replaced by a glut of a second species maintaining the presence of large numbers for long stretches of time. In Ohio, we have several large species of horse flies in the genus Tabanus.
Female horse flies require blood meals to be able to produce eggs to initiate the next generation, thus they search for large mammals from which to obtain their blood. When she finds a host, she uses her sharp mandibles to slash a wound in the skin and laps up the blood. The bite is extremely painful. Horse flies are adept at locating warm-blooded animals, including people near swimming pools, streams, ponds, marshy areas and in the woods. According to Missouri University entomologists, the flies apparently are sensitive to parts of the electromagnetic spectrum--their sight may be like "thermal vision" cameras used to detect heat leaks in houses. They are also attracted to large moving objects which give off heat, like cars and trucks.
Is their anything that can be done to deter these critters from biting? Not much! Suggestions include: avoid areas where horse flies (and deer flies) are most active; since the horse flies are active during the day, stay inside during daylight hours (this is not very practical when we have so many activities outside during the day to attend); stay alert while outside because unlike most other flies, the horse flys flight is silent, and they are known for landing stealthily on exposed skin then delivering a painful bite; and use an insect repellent containing DEET.
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WINDSHIELD WIPE
* CLEARWING BORER MOTH UPDATE. At least two species of clearwing borer moths continue to be active throughout Ohio, the LESSER PEACH TREE BORER, Synanthedon pictipes and the GREATER PEACHTREE BORER, Synanthedon pictipes. The next extremely important clearwing expected to start flight in the near future is the BANDED ASH CLEARWING BORER, Podosesia aureocincta. Based on growing degree day data, the banded ash clearwing adults should have begun emerging in southern Ohio (banded ash clearwing, adult emergence, 2,195 GDD and Hamilton County, Ohio GDD accumulation, 2,311). Ashes in landscapes, nurseries and especially recently transplanted ashes should be protected now with an application of insecticide to the trunks of these trees to prevent potential infestation and damage. Refer to OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" for further details on the management of the banded ash clearwing.
*Tim Malinich reported that a closer look at a suspect scale on the under side of a Cornus florida leaf revealed a round pupa with white fringe. This was not a scale, but the pupal stage of the MULBERRY WHITEFLY, Tetraleurodes mori.
* In a progress report on BAGWORMS, Thyridopteryx ephemeraeformis, Joe Boggs reported that populations seem to be at many points in their development (i.e., some caterpillars appear to be very young while others seem to be well on in their development, potentially close to pupation). Joe also has concern that some populations are far along enough in their development that if they were to be treated now with an insecticide, they would avoid the toxic effects of the insecticide by halting feeding, tying off their bags and pupating early. Thus, treatment of bagworms with an insecticide at this time could produce unsatisfactory control results. Bagworm populations were very high last year and may still be very high throughout the state again this year. If you have not checked previously infested plant material yet this year, dont waste anymore time. Excessive damage may have already occurred. Refer to OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" for further details on the management of the bagworm. Remember, it is way too late at this time to use Bt products.
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DISEASE DIGEST
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FIREBLIGHT FRENZY
Dave Shetlar reported an observation that some ornamental Callery pears are increasing their flagged branch appearance from FIREBLIGHT, (Erwinia amylovora). Of course this brought a firestorm of debate as BYGLers disputed whether these strikes were new infections of fireblight or latent infections currently exhibiting symptoms. This is just a reminder that fireblight can infect a tree by both blossoms and new, succulent, vegetative shoot tissues. The tiny bacterium can enter into the new shoots via wounding caused by hail, insects, wind causing branches to rub, pruning , and even the lenticles. Once inside the branch tissue, the bacteria replicate and produce a polysaccaride, which apparently plugs the xylem of infected shoots and twigs. This results in the characteristic wilting, death and "crooking" of infected shoots caused by the loss of turgor pressure in the cells. Symptoms usually appear 1-3 weeks after inoculation, depending on temperature and humidity.
For diagnostoids, remember that fireblight only occurs on plants in the Rosaceae family. Unfortunately, that is also the family that is the single largest contributor to the horticultural industry. From crabapples to ornamental pears, mountainash to contoneaster, from strawberries to chokecherries and all cherries in between, all have varying susceptibility to this disease. It is impossible to control, but the best management is to use genetic resistant. Just do the research and cultivar selections first...before your plantings go up in flames!
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BLUEGRASS COUSIN ROUGH TO KILL
ROUGHSTALK BLUEGRASS, Poa trivialis has been rearing its ugly seed heads in drought stressed lawns during periods of high heat. This prostrate growing perennial has the same boat shaped leaf tips and central vein as Kentucky bluegrass however it spreads on long, creeping stolons (stems) across other more desirable species of grass.
During cool, moist conditions, roughstalk bluegrass grows luxuriously and spreads quickly unbeknownst to the lawn manager. However, as the temperature rises, the leaves become dormant and large patches of turfgrass suddenly turn brown. Without looking closely at the stemmy brown plants, one might think that the lawn has a disease or insect infestation. Treated incorrectly, the lawn will continue to worsen.
To manage roughstalk bluegrass, treat the weed only with a selective systemic herbicide (glyphosate or glufosinate) when it is green and growing. Wait 10-14 days and retreat if necessary. Overseed bare areas with an improved cultivar of Kentucky bluegrass/perennial ryegrass seed mix in September.
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INDUSTRY INSIGHT
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CONUNDRUM CONSIDERED
BYGLers were again perplexed this week by reports of trees dropping their leaves prematurely. The ensuing discussion covered a wide range of possible causes, but offered no conclusive diagnosis. When faced with such a difficult puzzle, it is best to proceed one step at a time.
First, consider the tree itself. Some species react strongly to environmental stresses, such as flood or drought, by rapidly dropping leaves shortly after exposure to the stress. In other instances, the leaf drop may be a natural part of the life cycle. For instance, the inner needles of white pine will yellow prior to the end of their two year life on the plant. However, the amount of yellowing needles can panic the uninformed.
Second, look into insect or disease problems which may cause or contribute to stress-induced leaf drop. Girdling roots, cankers, and soil compaction are but a few conditions to examine when digging deeper into a diagnosis. Eliminating possible problems one at a time will narrow the scope of the investigation and hopefully lead to a conclusion.
Finally, exhausting all of the possibilities without reaching a conclusion can test your mettle as a diagnostician; can you admit that you just do not know? Far better to admit that the problem cannot be immediately solved than to spin a work of fiction resulting in improper treatments and unnecessary expense.
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COMING ATTRACTIONS
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OSU 2004 TURFGRASS RESEARCH FIELD DAY
The annual Turfgrass Research Field Day is scheduled for Wednesday, August 18 at the OSU Turfgrass Foundation Research and Education Facility in the Waterman Farm Complex. Starting at 9:30 am, attendees will learn about Fairway irrigation and water conservation, Green speed, topdressing/greensmix, shade physiology, dollar spot fungicide timing, chinch bug research, corn gluten use for weed control, entomopathogenic nematodes, new insecticides, Bermudagrass, foliar feeding of bentgrass and more! After the perennial BBQ lunch, take time to look at new equipment and demonstrations. Register with Ohio Turfgrass Foundation (OTF) and plan for an invigorating, intriguing day! Call OTF at 1-800-510-5296 to register.
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OSU-OLCA DIAGNOSTIC SEMINAR
The 10th annual Ohio Lawn Care Diagnostic Seminar arrives the following day, August 19 at the OSU Turfgrass Foundation Research and Education Facility in the Waterman Farm Complex. Group sessions start at 9:00 am in which registrants will rotate to different stops and learn about pesticide MOA, calibration and safety, lawn weeds, landscape plant problems, turfgrass insects and seeding establishment. For more information contact the OTF at 1-800-510-5296 to register.
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AGI GREEN INDUSTRY GET TOGETHER
A meeting is scheduled for September 9th, 2004 at the Willoway Nursery in Avon, Ohio (4534 Center Street). Dr. Norman Fausey of the USDA-ARS will discuss "Drainage and its Impact on the Urban Environment." This topic will be a major issue both the nursery and landscape industry will eventually face to comply with the Storm Water II regulations. The evening tour of Willoway Nursery will start at 3:30 pm. There is a $35.00 registration fee which covers the cost of the program and the meal. Dinner will be served beginning at 6:00 pm. You can register by sending your checks to AGI , Fall Get Together, P.O. Box 123, Painesville, Ohio, 44077-0123. Reservations are due September 1, 2004. For more information call Charles Behnke at 440-326-5851.
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BYGLOSOPHY
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"Gardening is a kind of disease. It infects you, you cannot escape it. When you go visiting, your eyes rove about the garden; you interrupt the serious cocktail drinking because of an irresistible impulse to get up and pull a weed." - Lewis Gannit
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