Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Dave Goerig, Tim Malinich, Jane Martin, Amy Stone, and Curtis Young
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July 27, 2006
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This is the Seventeenth 2006 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 July 25, 2006 conference included: Pam Bennett (Clark), Barb Bloetscher (Entomology/C. Wayne Ellett Plant and Pest Diagnostic Clinic), Jim Chatfield (Center at Wooster/HCS), Erik Draper (Geauga), Dave Dyke (Hamilton), Dennis Lewandowski (Plant Pathology), Becky McCann (ABE Center); Amy Stone (Lucas), and Nancy Taylor (Plant Pathology/CWEPPDC).
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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This week's weather summary includes data from July 1 July 17, 2006. Some parts of the state are still getting large amounts of rain while others are receiving it at just the right time. This weather summary includes information from 4 OARDC weather stations across the Buckeye state.
| Weather Station |
Region of Ohio |
Ave. High Temp F | Ave. Low Temp F | Ave. Temp F | Normal Ave. Temp F | Total Precip " | Normal Precip " | | Perry |
NE |
81.3 |
64.3 |
NA
|
NA |
2.98" |
NA |
| Hoytville |
NW |
83.9 |
62.0 |
72.9 |
72.7 |
3.05"
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1.99" |
| Oxford |
SW |
87.6 |
67.5 |
77.6 |
73.9 |
1.76" |
2.17"
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| Jackson |
South |
85.8 |
61.4 |
73.5 |
73.0 |
4.0" |
2.58" |
For a link to the OARDC Weather Stations, check out: http://www.oardc.ohio-state.edu/centernet/weather.htm
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HORT SHORTS
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WOODY PLANT OF THE WEEK: Thornless honeylocust
(Gleditsia triacanthos var.inermis)Earlier this spring, two frosts, the honeylocust plant bug complex, and in some cases, calico scale infestations, made many wonder if honeylocusts would ever leaf out gracefully. What many are noticing recently is that the vast majority have recovered, and are now gracing landscapes and urban forests with their finery.
Thornless honeylocusts are medium-sized (40-50 degrees) trees that provide dappled shade and a feathery foliage effect. They are fast-growing and extremely adaptable to a variety of soils, and are tough in urban landscapes. Cultivars include 'Sunburst' with electric yellow emerging foliage changing to light green in summer, 'Skyline' with a pyramidal form and dark green leaves, and 'Imperial' with a rounded growth habit.
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PERENNIAL OF THE WEEK
Crocosmia (Crocosmia xcrocosmiiflora) - This exotic-looking perennial is in bloom in central Ohio and is way cool! The tall, strap-like leaves have abundant flowers on the ends of the stems. Flowers can be yellow, orange, or red depending on the cultivar. 'Lucifer' is one of the most popular cultivars and is aptly named, with it scarlet flowers. Plants grow to 3' in height and are great massed in the back of a bed or border or it can even be used as a specimen. The flowers can also be used as a cut flower.
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PLANTS OF THE WEEK
Read all about perennials and landscape trees and shrubs in the ONLA publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio." The descriptions and photographs of plants were provided for these publications by the OSU ENLT Team along with other industry plant lovers. These full-color publications are available at http://Buckeyegardening.com for $5.00. Click on "garden store" and then "onla plant guides." ONLA members can purchase these in quantities at a reduced price at http://onla.org.
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BUG BYTES
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BLACK CATS IN THE CARROTS
The lovely black swallowtail butterfly, Papilio polyxenes has been noted floating through yards in search of plants in the Family, Umbelliferae, which include carrots, fennel, parsley, and coriander. Upon finding a suitable host plant, she will lay small yellow eggs singly on the lacy leaves. The hatching caterpillars initially are black with a few white stripes, then eventually have black and white rings with yellow dots. They are similar in appearance to the monarch caterpillar, which by the way, are also actively chewing leaves of milkweeds around Ohio.
If possible, allow these caterpillars to munch on a few plants and a finish their life cycle. In a few weeks, they will finish eating and form a greenish chrysalis down in the foliage of their host. The following spring, a gorgeous butterfly will emerge and flutter away, to lay more eggs for the next generation.
 
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STEM AND BULB NEMATODE ON GARLIC
A garlic sample submitted to the CWEPPDC last week looked dry, with discoloration (bleached appearance), and cloves were swollen and cracked. Upon microscopic observation, it was found to be infested with the Stem and Bulb Nematode, Ditylenchus dipsaci. Stem and bulb nematodes are widely distributed, especially in temperate regions.
The nematode is found primarily in plant tissue, but can be found in soil too. It parasitizes bulbs, stems, and leaves, but rarely roots. It enters the soil only when the tissue becomes unsuitable for feeding. This nematode has over 450 species of plants as hosts, including narcissus, tulip, phlox, daffodil, hyacinth, hydrangea, alfalfa, clover, onion, garlic, leek, shallot, carrot, pea, potato, sugar beet, turnip and strawberries.
The nematode may enter the tissue through stomata, lenticels and other natural openings, or directly through the epidermal cells near the soil line. It dissolves the parenchymatous tissue and feeds on the resulting goo. The stem and bulb nematode can survive repeated desiccation. Moisture reactivates the dry nematodes when infested material is replanted and comes in contact with moisture from the soil.
This nematode prefers clay soils and declines in population in sandy soils. Extension fact sheet by J. W. Noling from University of Florida can be referred to for management strategies
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DISEASE DIGEST
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GREEN GRAPES GONE BAD
Erik Draper reported that telephone calls had begun regarding frustrated backyard grape growers. Just as plans were being made as to how best use their bounteous harvest, suddenly a problem arises! Those green grapes develop a small purple-brown spot, which continues to enlarge, eventually turning the entire berry brown. The infected grape then begins to shrivel and turn black, like a raisin, and drops off. These are classic symptoms of BLACK ROT OF GRAPE, pathogen Guignardia bidwellii, a devastating fungal disease which affects both fruit and foliage of grapes.
Black rot, a foliar and fruit disease of grapes is considered to be one of the most damaging diseases of grapes. On leaves, the symptoms of black rot first appear as small yellowish spots. As these spots enlarge, a dark border forms around the margins of each lesion and the center turns reddish brown. Approximately two weeks after infection, the lesions are about 1/8-1/4" across and tiny, black, pimple-like structures appear inside of the lesion. The pycnidia are fungal fruiting bodies and contain thousands of spores, which can cause additional infections of young tissues like shoots, leaves and the berries.
Fruit symptoms often do not appear until the berries are about half grown. Infections begin as small, round, purplish-brown spots on the fruit. The spot enlarges quickly as the tissue in the spot softens, begins to rot and becomes sunken. The entire berry can go from green to entirely rotten in a few days. The diseased fruit shrivels, becoming small, hard, black and wrinkled raisins (mummies).
Control of this disease begins with sanitation. Clean up and get rid of the fruit mummies, and remove any diseased cane and/or tendrils from support wires during pruning. If only a few leaf lesions appear in the spring, remove the infected leaves. A good fungicide spray program is critical for managing this fungus. Fungicide applications should begin in the early season (bud break through bloom) and continue until the grapes begin to color or accumulate sugar (veraison). Fungicides like Nova (sold as Immunox for homeowners), Bayleton, Elite, Ferbam, Procure, Rubigan, Abound, Sovran, and Flint are the best for managing this disease. Once disease symptoms appear, severely infested plants or fruit are not likely to be rescued by fungicide treatments.
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FUNGICIDES FAIL, PART 8:
Fungi May Develop Resistance to Fungicides - The active ingredients of fungicides attack certain sites of fungal cells that result in affecting fungal metabolic processes and killing the cells. Of course, as with everything in nature, fungi fight back. Through genetic recombination and mutations, over time fungi develop various modes of overcoming the action of certain fungicides. Imagine a world in which a mutation occurs in a few individual spores out of millions and millions of spores of a particular fungal pathogen, conferring resistance of those spores to the mode of action of a particular fungicide. Imagine that you keep spraying that same fungicide over and over. The result would be that your spraying would be selecting for the survival of only the resistant strains of the fungus. Soon, only resistant strains would be present and the fungicide would lose its usefulness. The reality is that to a certain extent, this is exactly what happens.
Fungicide resistance is a real problem, and a good reason to rotate fungicides. For example, there are some great new fungicide products, called strobilurins (e.g. Heritage, Compass, Cygnus). Many applicators like them because the products are considered to be 'green fungicides', since they are derived from a naturally occurring organism, Strobilurus tenacellus, however, concerns have developed over the development of resistance to the strobilurins if used exclusively. The simple solution is to rotate your fungicide to different classes of fungicides, thus avoiding selecting for the resistant strains of the fungus. Diversify!
Other reasons for fungicide failures range from inadequate coverage of the susceptible parts of the plants (adjuvants are sometimes necessary) to phytotoxicity from using too high a rate or using a particular product on a sensitive plant. Good horticulturists know that you need to keep observing and learning to effectively use any plant management tool, and fungicides are no exception. One great learning resource for all pesticides is to READ THE LABEL. Recent polls show that fewer and fewer average Americans read pesticide labels. Let's make good examples on the claim that professional horticulturists are Lake Wobegon residents - all above average!
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WHITE SMUT ON GAILLARDIA
Gaillardia, known as blanket flower, has been diagnosed with white smut in Ohio. The initial symptoms are white or light colored spots approximately 1/4" diameter, which can be confused with spray damage or a virus infection. Light colored lesions later become necrotic in the center and the entire leaf eventually becomes necrotic. This disease is caused by a fungus (Entyloma sp.) that produces fungal fruiting bodies within the leaf tissue. Spread of the fungus requires high humidity.
Management of this disease is largely obtained through cultural methods, removing infected leaves and infested plant debris containing inoculum, and removing the most severely infected plants. Limited research has been done with regards to fungicide efficacy for control of this disease.
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THE MOIST CHAMBER
Nancy Taylor in the C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC) reported a busy week identifying diseases. Leaf discoloration and defoliation on Black-eyed Susan resulted from DOWNY MILDEW. A canker on dogwood was caused by a species of BOTRYOSPHAERIA while on a Juniper sample, a dry canker and branch death was caused by another species of BOTRYOSPHAERIA, specifically, Botryosphaeria stevensii. A sample of Harry Lauder's Walking Stick or Contorted Filbert had the characteristic lines of black spots caused by the EASTERN FILBERT BLIGHT fungus. Finally, the new emerging needles with tips browning on White Pine was determined to be that type of strange physiological leaf scorch triggered by numerous factors.
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INDUSTRY INSIGHT
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A BLACK AND WHITE ISSUE
Dave Dyke received a call from a commercial bramble grower who was quite upset about a significant portion of his RED RASPBERRIES and BLACKBERRIES being unmarketable due to "white spots" on the fruit. He said that he had seen just a little of the "white spotting" last year but that it was out of control this year. Two days later, when Dave arrived to look at the crop, the grower reported that the "white spots" were all gone. What was going on?
Brambles have aggregate fruits that are composed of many individual fruits called drupes. The "white spots" were actually individual drupes that had turned white. In spite of the fact that the blackberries had very distinct and pronounced white areas, the answer is not exactly black and white.
The University of Arkansas publication, "Crop Profile for Blackberries in Arkansas" states, "It is hypothesized that continuous feeding by THRIPS leads to white drupes on 'Apache' blackberry fruit at harvest and makes fruit unmarketable." http://www.ipmcenters.org/cropprofiles/docs/ARblackberry.html.
In, "White Spots on Brambles", G. E. Fernandez, NCSU, and Herb Styles, Southern Piedmont AREC, states, "Spots on individual drupelets of both blackberries and raspberries may be caused by a couple of things. STINKBUG feeding on young fruits will result in a random pattern of white spots on mature fruits. However, by the time that you notice the spots, the damage has been done by the stinkbugs and control is not possible for this year. A second cause of white spots is "SUNBURN" or "SUNSCALD". Sunscald damage differs from stinkbug damage in that the shoulder or side of the fruit exposed to the sun will have a blanched or "cooked" appearance while the shaded side looks normal. There are differences in susceptibility of various cultivars to sunscald among available varieties." http://www.smallfruits.org/Bramble/production/Archives/whitespots_bramble.htm.
Excellent photos of the "white spots" on brambles appear in "Blackberry Diagnostic Tool" http://www.ncsu.edu/project/berries/diagnostic_tool/flowers_and_%20fruit/white_spots_on_fruit.html, however, in that publication G. E. Fernandez says, "The cause of white drupes in blackberries is unknown, some think it may be due to stink bug damage during bloom, sun scald around harvest or another unknown physiological disorder."
To further confuse the issue, Barb Bloetscher, CWEPPDC, has said that TARNISHED PLANT BUGS may cause white drupes. Most likely, in this case, the fruit had been damaged by some insect, but by the time Dave was scheduled for a visit, all of the damaged fruit had been picked. Obviously, the answer to the exact cause of this black and white issue is not black and white.
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COMING ATTRACTIONS
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GATEWAY GARDEN JUBILEE IN CLARK COUNTY
On August 5th from 9:00 - 1:00 p.m., the gardens at the OSU Extension office in Clark County (Springfield) will be on display and nary a weed present (hopefully!). The Master Gardener volunteers of Clark County are hosting the event in an effort to showcase the Gardens. Enjoy over 200 varieties of annuals in the field trials, various herb and perennial gardens, the OSU turf and the vegetable research plots, a newly-renovated children's garden, and over 40 mixed containers. Hot dogs and drinks, music and fun and games are all available. The event is free and open to the public. For more details, contact 937-328-4607. For directions to the garden, go to http://clark.osu.edu. The event is held rain or shine.
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JULY DIAGNOSTIC WALKABOUT
On the North Coast is Monday, July 31 at 7:30 a.m. in the Cleveland/North Olmsted area. OSU Extension Educators Tim Malinich and Charles Behnke (retired) will once again take a look at landscape and turf problems during these early morning walkabouts. Recertification credits are available for category 8 and 6A. Call 216-429-8224 to request a registration flyer with more information.
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2006 NORTHWEST OHIO GREEN INDUSTRY SUMMER SESSION
The OSU Extension, Agricultural Business Enhancement (ABE) Center; OSU Extension, Lucas County; Owens Community College; and the Green Industry Educational Committee joined forces to sponsor this half-day educational event to be held August 2, 2006, at Owens Community College in Toledo. Attendees will hear the latest researched-based industry information, and have the opportunity to receive ODA, ISA, and ONLA re-certification credits.
The program will offer several training tracks covering a wide range of educational topics including: planting techniques; principles of good pruning; tree I.D.; water garden basics; using Ohio native plants; pesticide updates; using beneficial insects; basic turfgrass management; turfgrass disease management; turfgrass insect management; and using a digital camera to capture plant problems for diagnosis. Plus, there will be sessions on Workman's Compensation and other business issues. For more information, contact the OSU Extension, ABE Center office at (419) 354-6916, or visit: http://abe.osu.edu/green/commercial-horticulture/programs
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BYGLIVE! IN CINCINNATI
The 5th 2006 BYGLive! Diagnostic Walk-About in Cincinnati will be held on Monday, August 7, at the Cincinnati Zoo and Botanical Gardens. Participants will walk-about from 12:00 - 3:00 pm. with our hosts Steve Foltz (Director of Horticulture), Brian Jorg (Horticulture Manager), and others looking at plants, plant pests and diseases, animals, and other points of considerable interest.
Don't miss the annual plants trial and demonstration gardens jointly sponsored by OSU Extension, Hamilton County, the Cincinnati Flower Growers Association, and the Zoo! For more information on the Walk-About, contact Joe Boggs at: 513-946-8993.
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OSU TURFGRASS RESEARCH FIELD DAY and OHIO LAWN CARE SUMMER SEMINAR
Will take place Wednesday, August 16 and Thursday, August 17, respectively, at the OTF Research and Education Facility, 2551, Carmack Road, Columbus, OH.
For more information, contact Kevin Thompson at 614-501-1100, ext. 3151, or visit the OLCA website "calendar" at http://www.ohiolawncare.org/calendar/calendar.html
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TREE SURVIVAL SCHOOL for 2006
Will be held on October 4, 5, - 6 in Bay Village, Cuyahoga county. Randy Zondag and Alan Siewert will teach this three-day school. Class limited to 35 participants. ISA credits are available for certified arborists. For registration questions, call 440-225-7613.
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PESTICIDE LICENSE TRAINING SCHOOL
Is scheduled for October 10th in Lorain County. This is a training session for those preparing to take the test to obtain ODA Recertification credit in ornamental, turf or industrial vegetation. Put a hold on these dates, more information to follow.
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BYGLOSOPHY
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"There is nothing in a caterpillar that tells you it's going to be a butterfly". -Buckminster Fuller
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