“Perspectives in Diagnosing Landscape Plant Problems” HCS Course #210 - Landscape Horticulture November 4, 1999: “Perspectives in Diagnosing Landscape Plant Problems” HCS Course #210 - Landscape Horticulture November 4, 1999 Jim Chatfield
Ohio State University Extension
“The study, diagnosis, and treatment of plant diseases, penetrating to the very heart of darkness of nature gone wrong, is man’s most pressing calling.” - Jacques le Mauvais: “The study, diagnosis, and treatment of plant diseases, penetrating to the very heart of darkness of nature gone wrong, is man’s most pressing calling.” - Jacques le Mauvais
Plant Disease Defined: Plant Disease Defined “A malfunctioning of host cells and tissues that results from their continuous irritation by a pathogenic agent or environmental factor and leads to the development of symptoms. Disease is a condition involving abnormal changes in the form, physiology, integrity or behavior of a plant. Such changes may result in partial impairment or death of the plant or its parts.”
From: “Plant Pathology” - Agrios
For disease to occur which of the following are necessary?: For disease to occur which of the following are necessary? A. A virulent pathogen.
B. An environment conducive to disease development.
C. A susceptible host plant.
D. All three are necessary
for disease to occur.
True or False.: True or False. To control diseases with fungicides, applications must be made before the fungus enters plant tissue.
Which of the following is not a plant pathogen?: Which of the following is not a plant pathogen? A. Fungus (pl. fungi)
B. Bacterium (pl. bacteria)
C. Virus (pl. viruses)
D. Aphid (pl. aphids)
E. Nematode (pl. nematodes)
Are there plant pathogens in each of the five kingdoms of life on earth?: Are there plant pathogens in each of the five kingdoms of life on earth? A. Animals
B. Plants
C. Monera (Bacteria)
D. Protista
E. Fungi
Which of the following are ways that fungi and bacteria spread?: Which of the following are ways that fungi and bacteria spread? A. Contaminated seed
B. Wind-blown rain
C. Pruning shears
D. Animals
E. All of the above
Which of the following diseases is caused by the same fungus that causes powdery mildew of rose?: Which of the following diseases is caused by the same fungus that causes powdery mildew of rose? A. Powdery mildew of bluegrass.
B. Powdery mildew of lilac.
C. Powdery mildew of zinnia.
D. All of the above.
E. None of the above.
True or False.: True or False. Prior to World War II, rose black spot was worse than powdery mildew on greenhouse-grown roses; after World War II, powdery mildew was worse than black spot.
Which of the following are helpful in controlling black spot of roses?: Which of the following are helpful in controlling black spot of roses? A. Avoiding overhead irrigation, to the extent possible.
B. Plant in a sunny location.
C. Enhance air movement by weeding and pruning surrounding vegetation.
D. Use resistant varieties.
E. Use preventive fungicides.
F. All of the above.
Taxus (yew) does not thrive in overly wet, poorly-drained soil. Is this because its’ roots become unhealthy in such soils or because the wet soils are ideal for certain plant pathogens, such as water mold fungi? : Taxus (yew) does not thrive in overly wet, poorly-drained soil. Is this because its’ roots become unhealthy in such soils or because the wet soils are ideal for certain plant pathogens, such as water mold fungi?
With each of the following diseases, how do the fungal pathogens survive from one year to the next?: With each of the following diseases, how do the fungal pathogens survive from one year to the next? Crown gall
Verticillium wilt
Dutch elm disease
Apple scab disease
Diplodia tip blight
Phytopathological Paradigms:: Phytopathological Paradigms: 1. “Timing is everything” for chemical disease control.
2. Most plant problems are not infectious diseases.
3. Most infectious diseases cause little plant harm.
4. Symptoms develop well after infection.
5. Many pathogens have narrow host ranges.
Anthracnose Leaf Blights: Anthracnose Leaf Blights The time is late June. You have positive confirmation of anthracnose on samples of ash and sycamore that you sent in to the OSU Plant and Pest Diagnostic Clinic. You have tall tree spraying equipment and labeled fungicides for control of these diseases? Should you spray?
Phytophthora Root and Crown Rots: Phytophthora Root and Crown Rots True or False.
If you have a plant with Phytophthora root rot it will ultimately be killed by this fungus.
Rose Black Spot: Rose Black Spot This disease is caused by a fungus that infects rose leaves only if there is moisture on these leaves for a certain number of hours. Yet, there were tremendous outbreaks of this disease in some large rose gardens this past summer several weeks following a long, intense hot and dry spell.
WHY?
Verticillium Wilt Diseases: Verticillium Wilt Diseases All Conifers
Birch
Crabapple
Dogwood
Holly Oak
Pear
Planetrees
Sweet Gum
Willow What about this list is relevant to a discussion of Verticillium wilt disease?
Verticillium Wilt Diseases: Verticillium Wilt Diseases Ash
Barberry
Catalpa
Elm
Magnolia Maple
Redbud
Russian Olive
Tuliptree
Viburnum What about this list?
Verticillium Wilt Prevention & Management: Verticillium Wilt Prevention & Management Purchase of Verticillium-free plant material.
Water management
Maintain root health
Overall health management
Use of resistant varieties
Apple Scab Prevention & Management: Apple Scab Prevention & Management Use crabapple selections with good scab resistance and good horticultural qualities.
Early-season sprays, as soon as petals fall.
Proper pruning and sanitation.
Diplodia (Sphaeropsis) Tip Blight Prevention & Management: Diplodia (Sphaeropsis) Tip Blight Prevention & Management Site susceptible pines in moist, well-drained sites.
Promote root health.
Provide for good air movement.
Time sprays just before new growth develops.
Nematodes do which of the following?: Nematodes do which of the following? Parasitize plant roots
Parasitize plant stems
Feed on bacteria and fungi
Cause human disease
Live in soil
Live in water
Help control insects
Assisted Herb-icide: Assisted Herb-icide Poor Plant Selection
Planting Too Deep
Overmulching
Overwatering
Overfertilizing
Overmowing
Second Degree Girdling Are you guilty of the seven deadly sins of iatrogenicide?
Ten Contributing Factors In Disease Complexes:: Ten Contributing Factors In Disease Complexes: Defoliation by diseases or insects.
Drought or excess water.
Cold injury to bark tissue.
Root injury from compaction.
Direct root damage during construction.
Root injury from soil added over root system.
Girdling roots
De-icing salts
Trunk wounds
Nutrient deficiency
Tree Decline Prevention & Management: Tree Decline Prevention & Management Match tree to site.
Proper irrigation, fertilization, pruning and other maintenance.
Limit major environmental changes.
Proper diagnosis.
Realistic prognosis and removal decisions. From: “Plant Health Care for Woody Ornamentals” - Lloyd (Rane & Pataky)
Ten Keys to Plant and Site Selection: Ten Keys to Plant and Site Selection 1. Timing is everything.
2. Read the site.
3. Test the site.
4. Read the client.
5. Horticulturists, know they plants.
Slide28: 6. Size does matter.
7. Disease and pest resistance.
8. Consider all selection factors.
9. Special situations.
10. Expand our palettes.
Ten Keys to Plant and Site Selection - CONTINUED
Dr. Treevorkian’s Ten Rules for Plant Selection.: Dr. Treevorkian’s Ten Rules for Plant Selection. 1. Death & Taxus - Plant in wet sites.
2. Shade your rose garden unter der lindens.
3. Promote Japanese maples as the next grate street tree.
4. Try silver maples as foundation plants.
5. Companion plant tip of the day: Walnuts and tomatoes. 6. Plant ‘No Hopa’ crabapples.
7. White pines for the white
lines.
8. Basic Rhody Cocktail: Lots
of Water with a Lime
Chaser
9. Forever Impatiens.
10. Zoysiagrass: Grave blankets of the future.
“All crabapples are pretty much the same, except for disease resistance.” - George Blakeslee: “All crabapples are pretty much the same, except for disease resistance.” - George Blakeslee
Malusize Your Mind!: Malusize Your Mind!
Apple Scab Rating System:: Apple Scab Rating System: 0 = No scab noted.
1 = Slight scab, less than 5% of leaves affected.
2 = Moderate scab, 5%-20% of leaves affected, some
yellowing, little or no defoliation.
3 = Extensive scab, 20%-50% of leaves affected,
significant defoliation.
4 = Heavy scab, 50%-80% of leaves affected, severe
defoliation.
5 = Extreme scab, 80%-100% of leaves affected, complete or near-complete defoliation.
Secrest Crabapple Trials: No Scab - 1993-1996: Secrest Crabapple Trials: No Scab - 1993-1996 Malus baccata ‘Jackii’
‘Beverly’
‘Bob White’
‘Dolgo’
‘Prairifire’ ‘Red Jewel’
Malus sargentii
‘Silver Moon’
Malus tschonoskii
‘White Angel’ *Based on 14 ratings over 4 years.
Key Features of Ornamental Crabapples:: Key Features of Ornamental Crabapples: Fruit
Flower
Form
Foliage
The term fruitless crabapple is an oxymoron!: The term fruitless crabapple is an oxymoron!
Aesthetics Rating System:: Aesthetics Rating System: 1 = Exceptionally ornamental crabapple
2 = Highly ornamental crabapple
3 = Adequate as ornamental crabapple
4 = Substandard as ornamental crabapples
5 = Unacceptable as ornamental crabapple.
Not recommended. Based on flower, foliage, fruit or form at time of ratings.
Secrest Crabapple Trials: Aesthetic Ratings - 1993-1996: Secrest Crabapple Trials: Aesthetic Ratings - 1993-1996 ‘Molten Lava’ 1.7
‘Donald Wyman’ 2.2
‘Red Jewel’ 2.2
‘Prairifire’ 2.4
‘Sentinel’ 2.4
‘Mary Potter’ 2.5 ‘Strawberry 2.5
Parfait’
‘White Cascade’ 2.5
‘Bob White’ 2.6
‘Sugar Tyme’ 2.6 *Based on 50 ratings over 4 years.
Secrest Crabapple Trials: Aesthetic and Scab Ratings - 1993-1996: Secrest Crabapple Trials: Aesthetic and Scab Ratings - 1993-1996 ‘Molten Lava’ 1.7 1.1
‘Donald Wyman’ 2.2 1.1
‘Red Jade’ 2.2 1.2
‘Prairifire’ 2.4 0.0
‘Sentinel’ 2.4 0.7
‘Mary Potter’ 2.5 0.5
‘Strawberry Parfait’ 2.5 0.1
‘White Cascade’ 2.5 2.2
‘Bob White’ 2.6 0.0
‘Sugar Tyme’ 2.6 0.7
Secrest Crabapple Trials: Scab and Overall Ratings - 1993-1996: Secrest Crabapple Trials: Scab and Overall Ratings - 1993-1996 Malus baccata ‘Jackii’ 0.0 2.8
‘Beverly’ 0.0 3.7 Ugly fruit mummmies
‘Bob White’ 0.0 2.6
‘Dolgo’ 0.0 4.1 Large, messy fruits
‘Prairifire’ 0.0 2.4
‘Red Jewel’ 0.0 2.2
Malus sargentii 0.0 3.1
‘Silver Moon’ 0.0 3.4
Malus tschonoskii 0.0 DEAD Fireblight
‘White Angel’ 0.0 3.6 Awkward shape
OSU Crabapple Team Projects:: OSU Crabapple Team Projects: Aesthetic Evaluations
Fruit and Flower Longevity Studies
Disease and Insect Evaluations
Rootstock Studies
Fertilization Studies
Crablandia
Crabaganza 2000!
CrabNet
Brooklyn Botanic Gardens
All hollies do poorly in wet sites.: All hollies do poorly in wet sites. A. True
B. False
Plants typically considered acid-loving include:: Plants typically considered acid-loving include: A. River birch
B. Red maple
C. Pin oak
D. All of the above
Once planted, it is easy to alleviate iron chlorosis problems on trees.: Once planted, it is easy to alleviate iron chlorosis problems on trees. A. True
B. False
Which plants in each of the following pairs will do better in wet sites:: Which plants in each of the following pairs will do better in wet sites: A. Taxus or Taxodium
B. Norway maple or red maple
C. American holly or winterberry holly
Which of the following three components of the disease triangle should be considered when making plant selection decisions.: Which of the following three components of the disease triangle should be considered when making plant selection decisions. A. Susceptible host plant
B. Virulent pathogen
C. Environment conducive to disease
D. All of the above
For which of the following plants should susceptibility to Verticillium wilt disease be a selection consideration in replant decisions?: For which of the following plants should susceptibility to Verticillium wilt disease be a selection consideration in replant decisions? A. Smokebush
B. Japanese maple
C. Redbud
D. All of the above
‘Dolgo’ crabapple has excellent genetic resistance to apple scab disease: ‘Dolgo’ crabapple has excellent genetic resistance to apple scab disease A. True
B. False
‘Dolgo’ crabapple is an excellent choice for a site near a sidewalk entrance to a hospital: ‘Dolgo’ crabapple is an excellent choice for a site near a sidewalk entrance to a hospital A. True
B. False
Which of the following is not true?: Which of the following is not true? A. Tomatoes are sensitive to juglone from black
walnut trees.
B. ‘Adirondack’ crabapples are spreading weepers.
C. In most cases, tar spot of maple causes little damage
to plant health.
D. Cytospora canker is a common disease of spruce.
Flowering dogwoods should be planted in either full sun or dense shade situations.: Flowering dogwoods should be planted in either full sun or dense shade situations. A. True
B. False
True or False: True or False Bald cypress should be planted only in wet, swampy sites.
True or False: True or False Katsuratree should only be planted in shady, protected locations.
True or False: True or False All rhododendrons need shady locations.
Guignardia Leaf Blotch of Aesculus: Guignardia Leaf Blotch of Aesculus Aesculus glabra
Aesculus hippocastanum
Aesculus pavia
Aesculus octandra
Aesculus x arnoldiana ‘ Autumn Splendor’
Aesculus parviflora Which of the following is least susceptible to this disease?
Examples of Roses Resistant to Black Spot:: Examples of Roses Resistant to Black Spot: Hybrid Teas: Chrysler Imperial, Tropicana
Floribundas/Grandifloras: Betty Prior, Sonia
Shrub Roses: All That Jazz, Carefree Wonder
Miniatures: Gourmet Popcorn, Rose Gilardi
Rugosa Hybrids: Polyantha, The Fairy
Note: Resistance may vary from one area to another.
PLANT FAMILIES: PLANT FAMILIES A. Amelanchier --- serviceberry
B. Aronia --- chokeberry
C. Cotoneaster --- cotoneaster
D. Crataegus --- hawthorn
E. Malus --- crabapple
F. Potentilla --- potentilla or cinquefoil
G. Prunus --- cherry, almond, plum
H. Pyracantha --- firethorn
I. Pyrus --- pear
J. Sorbus --- mountainash
K. Rosa --- rose
L. Spiraea --- spiraea
What is the plant family for these ornamentals?
These plants are all in the rose family (Rosaceae).: These plants are all in the rose family (Rosaceae). True or False
Bacterial fireblight occurs only on plants in the rose family.
What family are the following plants in and what are a few cultural requirements that they share?: What family are the following plants in and what are a few cultural requirements that they share? A. Enkianthus
B. Kalmia
C. Rhododendron
D. Vaccinium
Diagnose this problem.: Diagnose this problem. You own a garden center and one of your best customers brings in several twigs of a rhododendron. Some of the leaves are gone but others still remain on the twig, brown and rolled up in little cylinders. What might the problem be?
Diagnose this problem.: Diagnose this problem. You are a landscape installer and while on a job, a neighbor of your customer stops over, admires your work , and asks you to take a look at a few plants in their yard. They expect that the problem is due to lawncare herbicide injury. They show you a silver maple that has new foliage with parallel venation and leaf strapping, Taxus that has yellowed new foliage, and a Trident maple with curled leaves. What do you tell them?
Dieback of branches on maple might be due to which of the following:: Dieback of branches on maple might be due to which of the following: A. Verticillium wilt disease
B. Root decline
C. Salt injury
D. Winter injury
E. Trunk damage
F. All of the above
Common Ornamental Fungicides:: Common Ornamental Fungicides: Common Name
metalaxyl
PCNB
thiophanate-methyl
triadimefon
triforine
vinclozolin Brand Name(s)
Subdue
Terrachlor
Cleary’s 3336, Domain, Fungo
Bayleton
Funginex
Ornalin
Plant Disease Publications You Should Have:: Plant Disease Publications You Should Have: “Buckeye Yard and Garden Line” (fischnich.1@osu.edu) and “Buckeye Yard and Garden online” on Horticulture in Virtual Perspective (http://hortwww-2.ag.ohio-state).
“Diseases of Landscape Plants”. OSU Extension Offices. Revised edition due out in Winter of 1997.
Plant Disease Publications You Should Have:: Plant Disease Publications You Should Have: “Common Insect Pests and Diseases of Ornamental Trees and Shrubs.” Slide sets, color pictures, fact sheets developed by OSU Extension. Published by Ohio Nursery and Landscape Association.
800-825-5062.
“Diseases of Trees and Shrubs”. Wayne A. Sinclair, Howard H. Lyon & Warren T. Johnson. 1987. Cornell University Press, 124 Roberts Place, Ithaca, NY 14850.
Buckeye Yard & Garden Line E-mail Subscription Jim Chatfield OSU Extension - Northeast District 1680 Madison Avenue Wooster, OH 44691 Phone: 330/263-3831 FAX: 330/263-3667 E-Mail: chatfield.1@osu.edu: Buckeye Yard & Garden Line E-mail Subscription Jim Chatfield OSU Extension - Northeast District 1680 Madison Avenue Wooster, OH 44691 Phone: 330/263-3831 FAX: 330/263-3667 E-Mail: chatfield.1@osu.edu
Buckeye Yard & Garden onLine http://www.hcs.ohio-state.edu/bygl.html: Buckeye Yard & Garden onLine http://www.hcs.ohio-state.edu/bygl.html
In What Other Job Would You Get to:: In What Other Job Would You Get to: Teach in a one-room schoolhouse by kerosene lantern?
Disagree with Ronald Reagan on Network TV?
Have pesticide recommendations be received with hallelujahs?
Intertwine stories of family & plant growth for hundreds of thousands?
Have freedom to create informational resources used nationwide?
The average salaries for OSU Extension Agents are:: The average salaries for OSU Extension Agents are: Agr. & Natural Resources - $42,707
Family & Consumer Sciences - $38,840
4-H - $37,368
Community Res. Development - $38,578
What Field Faculty Do:: What Field Faculty Do: Writing for trade publications, media, journals.
Teaching a wide variety of topics locally and state-wide.
Representing OSU and agricultural science to the media and public.
Troubleshooting diagnostic challenges.
Team-Working at many levels.
Creating new ways to help clientele.
Developing specialized expertise.
BONUS: Which of the following song lyrics are correct?: BONUS: Which of the following song lyrics are correct? . “Clown control to Mao Zedong.”
. “Ants are my friends.”
. “The girl with colitis goes by.”
. “Scuse me while I kiss this guy.”
. “And Lady Mondegreen.”
. None are correct.