SOMETHING TO GROW ON
April 1999

It is April and the Year of the Dogwood. Dogwoods have been very poor over the past few years. I was losing faith in the tree that built and long supported the Middle Tennessee and North Alabama Nursery Industry. My confidence and love of this tree has been restored with the explosive show this year. It is odd that middle and north Alabama are ahead of south Alabama in dogwood blooming this year. It has been cooler and wetter in the south this spring and that has changed the natural order of things. I hope the south enjoys the wonderful flowers we are getting right now.

It is appropriate that Drs. Eakes, Gilliam, Keever, Williams and Hardin have completed their research of dogwood cultivar evaluations and have submitted their results for publication. The trees were located in Auburn and planted in full sun. The information on their findings are listed below. I was sorry the Rutger hybrids (C. florida x kousa) did not do well in our area. They are beautiful further north. The odd problem with the hybrids is that they are not hardy in the south. There is not enough cold weather during some years for them to go dormant and then when we get one of our southern extreme freezes, the new hybrids can not tolerate the cold. The same fatality problem experienced in Auburn occurred in Brewton, another dogwood planting site.

I was fortunate to be able to attend the ALCA (Associated Landscape Contractors of America) program at the University of Kentucky last month with a great group of sharp Auburn students and Dr. David Williams and Dr. Joe Eakes, the ALCA Team leaders. It was fun just to get out with the students and take a road trip but I really had an eye-opener attending my first ALCA event. Dr. Williams describes the event and the results below but I would like to challenge all the landscape companies reading this newsletter to go to the program at Mississippi State next year. If you are looking for good people to build your company, this is the place to find them. It is a contest for the students but it is also a large job fair with about 80 companies attending to recruit the cream-of-the-crop of students from 45 schools and universities across the country. The students who go are highly motivated, spending a large number of volunteer hours in study and practice to attend the event. The students get some financial help from industry but they also spend a lot of their own money to go because the university does not offer any financial support. When students spend their own money and take time away from their social life to be involved in this program, you know that they are special and could make a difference in your business. Keep an eye on the newsletter and we will keep you informed for next year so you can get a booth and get access to this pool of exceptional people.

A new trend may be emerging to further fuel the boom in the green industry. I heard a segment on the news discussing an emerging trend in California. Developers are taking dated, declining strip malls and converting them into planned community living spaces with emphasis on large expanses of common green space. We have operated under the bulldoze, pave and plant buildings program for a long time. It is nice to see that designers, contractors and city officials are finally getting the message that there is an economic benefit in landscaping (see article below from Clemson on value of landscaping). The projects feature small, landscaped, centralized shopping areas (downtown), neighborhood schools, mixed one, two and three bedroom homes with smaller yards but with large designer-landscaped common green spaces. Streets offer a European look with well-landscaped streets, sidewalks and separate bike paths. Post Properties in Atlanta took the lead and set new standards for apartment landscaping. Now that someone has taken the lead, set the standard and showed a large number of people the value of landscaping in urban areas, I hope the word-of-mouth spreads fast. It will not only offer great opportunities for our industry but a higher quality of life for everyone.

Have a great April! The Horticulture Department and Auburn University were created to serve all the people of Alabama and we enjoy helping when we can. Send us your questions, comments, suggestions, and ideas.

Ken Tilt


DISCLAIMER: Please remember that all information presented is a summary of research and not an endorsement of any product or a recommendation of chemicals. The official labels from the manufacturing companies offer the legal and proper use and handling information for all products.

THE FOLLOWING ARTICLES ARE FEATURED IN THIS MONTH'S SOMETHING TO GROW ON:

1. Auburn University Students Excel at ALCA Student Career Days
2. Mortality and Growth of Dogwood Selections in the Southeastern United States
3. 1999 Louisiana and Mississippi Winners Announced
5. Birmingham Botanical Gardens Releases List of Best Local Rose Varieties
6. Barley Straw to Control Pond Algae
7. The Popular Ornamental Sweet Potato - A Warning
8. More on Ornamental Sweet Potatoes
9. 1999 Georgia Gold Medal Winners
10. How to Combat the Two-Spotted Spider Mite on Buterfly Bushes
11. Rhododendron Stand-Outs
12. Enhancement of Home Value by Landscaping
13. Bacterial Diseases Alert in Geranium
14. Battling Liverwort in Nursery Production
15. Ants vs. Greenhouse Beneficials
16. Notes from Jackie Mullen at the Plant Pathology Lab
17. New Fire Ant Bait Products
18. UPCOMING EVENTS

AUBURN UNIVERSITY STUDENTS EXCEL AT ALCA STUDENT CAREER DAYS

The 23rd Associated Landscape Contractors of America Student Career Days was held in Lexington, Kentucky on March 18-21. Auburn University placed 14th out of 44 schools, a new record in number of participating institutions. For the third consecutive year Auburn's standing represented the highest score among the Southeastern Conference schools that participated. 600 students participated in the competition. Top honors went to the following students:

Fourteen other students finished among the top 20 in their events.

Industry representatives were very enthusiastic about the Auburn students and offered internship and career opportunities on the spot. The state and university were very well represented by this group of students.

(from Dave Williams and Joe Eakes, Auburn University)


MORTALITY AND GROWTH OF DOGWOOD SELECTIONS IN THE SOUTHEASTERN UNITED STATES

A study conducted at Auburn University from May 1996 to March 1998 observed differences in 38 dogwoods of 4 main types: flowering dogwood, giant dogwood, kousa dogwood, and kousa x flowering dogwood hybrids. Researchers concluded that flowering dogwood selections are better performers in full sun of the Southeast than giant dogwood, kousa dogwood, and kousa x flowering dogwood hybrids based on plant mortality. Of the flowering dogwood selections with white bracts and green foliage, 'Barton', 'Cloud 9', 'Fragrant Cloud', 'Ozark Spring', and 'Welch Bay Beauty' were the best performers while 'Autumn Gold' and 'Wonderberry' were the worst. 'Cherokee Brave', 'Cherokee Chief', and 'Pink Beauty', and f. rubra were the best performers with red or pink bracts and green foliage. Among the selection with variegated foliage, 'First Lady' was the only selection that performed well, while 'Cherokee Sunset' and 'Rainbow' performed poorly.

(by B.R. Hardin, D.J. Eakes, C.H. Gilliam, G.J. Keever and J.D.Williams, Auburn University)

1999 LOUISIANA AND MISSISSIPPI WINNERS ANNOUNCED

From Allen Owings at the LSU Agricultural Center comes information about the 'Louisiana Select' and 'Mississippi Medallion' winners for this year. 'Lady in Red' salvia is the 'Louisiana Select' winner. The Mississippi winners are 'Tonto' and 'Sioux' crapemyrtle, 'Biloxi Blue' (aka 'Blue Princess') perennial verbena, and 'Indian Summer' rudbeckia.

(from Allen Owings, LSU)


BIRMINGHAM BOTANICAL GARDENS RELEASES LIST OF BEST LOCAL ROSE VARIETIES

The Birmingham Botanical Gardens has released a list of rose varieties that they have rated excellent for the Birmingham area. This list will benefit home gardeners as well as nursery owners. One asterisk next to a variety indicates that no Blackspot was found on the leaves and two asterisks indicate less than 1% of the leaves were infected. Of course the cultural practices of the gardens are rather rigorous and roses were obviously grown under those conditions. The varieties are as follows:
  • Betty Boop
  • Brass band
  • Brigadoon
  • Carefree Delight**
  • Caribbean
  • Elina
  • Fame
  • Flower Carpet*
  • Fountain Square
  • Fourth of July*
  • Impatient
  • Irresistible
  • Jean Kennealy
  • Livin' Easy**
  • Medallion
  • Midas Touch
  • Mister Lincoln
  • Olympiad
  • Polarstern
  • Rio Samba
  • Secret
  • Sheer Bliss
  • Star Glow
  • Summer Dream
  • Summer Snow
  • Sunset Celebration
  • Sunsprite**
  • Touch of Class
  • Voodoo
The Botanical Gardens uses this spray program: Every 7 days they spray with a mixture of five commercial products: Triforine (Funginex) and Dithane M-22 are mixed together for black spot fungus prevention. Orthene for insects; Avid for spider mites; Rubigan for powdery mildew are added on an "as needed" basis.

The Fertilizer program: 1st. application in the Spring using 13-13-13. After the first flush of blooms, they make another application using Nursery Special; then another application of Nursery Special about mid July and then nothing else until the following Spring.

(from The Birmingham Botanical Gardens)


BARLEY STRAW TO CONTROL POND ALGAE

From the HortIdeas electronic newsletter:
"HortIdeas reader MaryAnna Anderson recently brought to our attention information from various sources about putting barley straw bales in ponds to control algae (which not only are aesthetically objectionable, but also can clog pumps and filters). In England, the Centre for Aquatic Plant Management has proven this method for stopping algae growth in trials conducted over a period of several years. Here’s a synopsis of the CAPM’s current recommendations, based on a paper given out at a professional horticultural clinic in Nebraska in January of this year by Dr. Roch Gaussoin, turfgrass specialist at the University of Nebraska (e-mail rgaussoin@unl.edu, phone 402-472-8619):

Barley straw does not kill already existing pond algae. Best results are seen in ponds that are amply oxygenated. Approximately one ounce of barley straw per 10 square feet of pond surface area is suggested; additional straw sometimes can work better in ponds that have had severe algae problems in the past, but too much straw can cause deoxygenation. Place the straw loosely in cages or nets, so water can easily pass through it, and position at or near the surface of the water; use several small bales rather than one large bale. Install the bales in the fall or early spring, allowing plenty of time prior to peak algae bloom period (spring and summer); higher ambient temperatures will accelerate the onset of algae. The straw will provide suppressive effects for about six months. No negative effects on pond organisms have been reported."
(from HortIdeas Online, April 1999)


THE POPULAR ORNAMENTAL SWEET POTATO - A WARNING

Eddy Edmonson, Texas Nursery and Landscape Association President, is worried about the growing popularity of ornamental sweet potatoes such as Ipomoea "Blackie" and "Margarita". He and other producers are afraid that the importation of these plants could lead to infestation of the sweet potato weevil (Cylas formicarius) into weevil-free areas as it is illegal to transport any portion of sweet potato plants from quarantine areas into non-infested areas. For more information phone 1-800-880-0343.

(from the Greenbeam)


MORE ON ORNAMENTAL SWEET POTATOES

Now that we've warned you about the weevil problem associated with ornamental sweet potatoes, we'll give you more information so that you can decide whether they are a good match for your garden or business. The advantages are many: rapid growth as a ground cover; intense foliage color in the summer; rapid establishment; heat tolerance; multiple uses; minimum disease problems. The disadvantages include: need for warm growing conditions; limited cultivar availability; no flower production; sweet potato looper; white flies.

There are currently three main cultivars that are available: 'Blackie' - deeply cut dark purple/black leaves; 'Marguerite' - heart-shaped chartreuse lime green leaves; 'Tricolor' (also called 'Pink Frost') - multi-colored cultivar with green, pink, and white foliage. Tricolor is more sensitive to shade and cooler temperatures. It requires less pruning, though, than 'Blackie' and 'Marguerite'. Evaluations are being conducted currently in Louisiana.

(from Allen Owings, LSU Extension Horticulturist)


1999 GEORGIA GOLD MEDAL WINNERS

The Georgia Plant Selections Committee, Inc., a non-profit organization with the goal of promoting production, sale, and use of superior Georgia-grown ornamental plants, has each year since 1994 selected an annual flower, herbaceous perennial, shrub, and tree as Georgia Gold Medal Winners “for superior performance.” These are low-maintenance plants that are well adapted to the southeastern U.S. 1999 Winners are Pentas lanceolata ‘Nova’, Helleborus orientalis, Viburnum × burkwoodii ‘Mohawk’, and Cladrastis kentukea. For additional information, contact University of Georgia extension horticulturist Gary Wade (phone 706-542-2861, e-mail gwade@uga.edu).

(from HortIdeas Online, April 1999)


HOW TO COMBAT THE TWO-SPOTTED SPIDER MITE
ON BUTTERFLY BUSHES

The two-spotted spider mite is the most damaging pest of the butterfly bush (Buddleia taxa), a very popular ornamental shrub known for its sweet fragrance that attracts nectar feeding butterflies to gardens. Damage caused by the two-spotted spider mites includes stippling, chlorosis, and leaf damage - significant enough to make plants hard to market.

Horticultural and agronomic crops have been examined for their resistance to this costly pest. Research in the past on butterfly bushes speculated that the resistance was associated with plant chemistry. It is known that glandular trichomes (a hair or a scale) that may contain defensive compounds are present on the leaves of some Buddleia species.

A laboratory method used to assess susceptibility of plants to this mite is the use of leaf disk bioassays (small disks of leaves cut from the plant and put in a glass laboratory dish). The number of eggs laid on the disks by the mites indicates how susceptible the plant is to damage. This study was conducted to determine if there are differences in two-spotted spider mite resistance among Buddleia taxa and ascertain the effects of trichomes and surface compounds.

The larger the quantity of hairs seemed to correlate with the lower number of eggs laid. Species with compounds present on the leaf surface that repel mites are also a good selection. Using this information should help growers produce butterfly bushes that are more resistant to this pest, thus requiring fewer pesticide applications. Healthier, more aesthetically appealing plants would result.

(from an article entitled "Gradients in Susceptibility and Resistance Mechanisms of Buddleia L. Taxa to the Two-spotted Spider Mite (Tetranychus urticae Koch)" published in the J. Amer. Soc. Hort. Sci. 124(2):114-121, 1999 by Jeffrey H. Gillman, Michael A. Dirr, and S. Kristine Braman).


RHODODENDRON STAND-OUTS

In a recent survey of the membership of The Southeastern Chapter of the American Rhododendron Society, members listed 268 cultivars as "Good Doers." Those listed below got a 60% or higher rating from society members. To get the whole list you can contact the chapter president, Ed Collins, at azaleaed@brinet.com :

(from Richard E. Bir, NC)


ENHANCEMENT OF HOME VALUE BY LANDSCAPING

"Clemson University economist Mark Henry has studied the effect of landscaping on home market value in Greenville, South Carolina, using data collected in 1996 and 1997. The results are similar to those of a previous study conducted in Greenville from 1991 through 1993, in which improving landscaping from “poor/average” to “good” raised home value by 7-9%, while improving landscaping from “good” to “excellent” raised home value by 4-5%. The 1996-97 data indicated that improving landscaping from “average” to “good” raised home value by 4-5%, while improving landscaping from “good” to “excellent” raised home value by 6-7%. Henry writes as follows about making judgments regarding the quality of particular home landscapes in his study: A landscape design and real estate professional carried out the on-site surveys of the 218 homes.... The quality of the landscaping was evaluated both from the point of view of the type, size, and condition of plants, trees, etc., and how they were placed on the lot. Thus, the admittedly subjective concepts of balance, symmetry, sense of proportion, and unity entered into the evaluations. In 1996-97, most of the landscapes were judged to be good (27%) or average (36%). About 15% were excellent and 22% were poorly landscaped. Location attributes also influence home prices ... Some non-landscaping features were held constant by ... choice of the sample units.... variation in home sale prices because of differential zoning ... was eliminated by restricting the sample to single-family homes in the same tax district ... Reference: Mark S. Henry, “Landscape Quality and the Price of Single Family Houses: Further Evidence from Home Sales in Greenville, South Carolina,” Journal of Environmental Horticulture 17(1), March 1999, 25-30. (Horticultural Research Institute, 1250 I St., N.W., Suite 500, Washington, DC 20005.)"

(from HortIdeas Online, April 1999)

BACTERIAL DISEASES ALERT IN GERANIUM

Two rather destructive bacterial diseases have already begun to infect geranium this year. The first is bacterial wilt (Xcp) of geranium which usually infects plants much later in the growing season. Growers need to begin scouting their greenhouses looking for symptoms. The initial sign is wilt on some part of the plant, particularly in the heat of the day or when there is some sort of moisture stress. Examine the roots of wilted plants and if root rot is not present then you can probably assume that it is Xcp. Test affected plants at a university or private lab. There is currently no cure for this disease so affected plants must be discarded to arrest the spread of the disease. Copper-based compounds such as Phyton-27 and Kocide 101 should be applied to non-infected plants to help slow the spread of the disease.

If plants are wilted and Xcp is ruled out, the problem may be another bacterial disease (Ps). It is not as common in the greenhouse but can be just as destructive. Unlike Xcp, Ps can infect other greenhouse bedding plants such as impatiens, mums, gerbera, zinnia, petunia, salvia, and marigolds. Attention to this problem may help you prevent a major disaster.

(from Stephen T. Nameth and the Ohio Florists' Association Hotline)


BATTLING LIVERWORT IN NURSERY PRODUCTION

Nursery growers are often faced with the problem of liverworts and mosses growing in their container plants. Light, temperature, humidity, growing media, irrigation and fertility programs needed by new plants are ideal conditions for liverwort growth. They are small plants, over 10,000 species. The genus that infects most potted plants is Marchantia, a very adaptable plant. Liverworts make nursery floors slippery, provide a home for fungus gnats, food for slugs and snails. In containers they absorb water from the plant and make the plants unsuitable for sale.

Liverworts are propagated by the wind, when water drops onto part of the plant, and by breaking off and growing anew. In greenhouses care must be taken at the doors or openings as liverworts are often blown in. It's important to eliminate wet and weedy areas around nurseries. Sanitize all greenhouse surfaces between crops with products like EcoClear and Zer-Tol. Reduce or eliminate overhead irrigation to prevent propagation by splashing. Keep the surface of the growing medium loose and dry. When nitrogen is in the 75 to 250 ppm range liverwort grow well. If you can grow plants with a lower nitrogen level you may have some success in slowing the establishment of liverwort on your plants. Applying fast-drying mulch also helps. Examples are rice hulls, hazelnut shells (not crushed), pumice, turkey grit and oyster shells. Geotextile discs work but only if both sides have been treated with copper compounds (e.g. SpinOut). The application of heavy metal fertilizers on the surface of the growing medium helps.

The use of pre-emergent herbicides, particularly oxadiazon (Ronstar, Regal 0-0) or oryzalin (Surflan, Rout) may contribute to the eradication of liverwort. These pre-emergent herbicides, though, must be carefully monitored as they may lead to damage to the container plants. The combination of physical techniques, surface iron or copper fertilizer applications, and pre-emergent herbicides has nearly eliminated liverworts in several nurseries.

To eliminate liverwort, growers need to focus on a balanced plan of attack, combining physical controls, surface fertilizers, pre-emergent herbicides, and post emergent controls. Wind and water are constantly delivering new spores so the balanced attack must be vigilant and constant.

(from "Controlling Liverworts and Moss in Nursery Production" by Sven E. Svenson, Bill Smith and Bruce Briggs, published in the Combined Proceedings of the International Plant Propagators' Society, Volume 47, 1997).


ANTS VS. GREENHOUSE BENEFICIALS

"Difficulties in establishing beneficial insects (specifically Encarsia and Eretmocerus) in a North Carolina State University greenhouse last spring led NCSU horticulturist Mary Peet to look for a cause. She discovered ants, which she believes either eat immature beneficials or protect aphids and whiteflies from the beneficials. In the fall, after using boric acid to destroy ant nests near the greenhouse, it was easier to establish beneficials. For more details, contact Mary Peet, North Carolina State University, Dept. of Horticultural Science, Box 7609, Raleigh, NC 27695, phone 919-515-5362. Reference: Anonymous, “Ants Could Affect Biocontrols,” Greenhouse Management & Production 19(1), January 1999, 12. (Branch-Smith Publishing, 120 St. Louis Ave., Fort Worth, TX 76104.)"

(from HortIdeas Online, April 1999)


NOTES FROM JACKIE MULLEN AT THE PLANT PATHOLOGY LAB

Most of the February samples were landscape ornamentals with 2/3 of the problems being abiotic. Biotic diseases seen were spring black stem and leaf spot (Phoma), Phytophthora root rot on dwarf English boxwood, anthracnose on Crinum, Pythium root rot on English Ivy, Volutella canker on Hibiscus, Phytophthora and Pythium root rot on hydrangea; Colletotrichum leaf spot on southern magnolia, Phythium root rot on maple, Cercospora leaf spot and Pythium stem rot on pansy, Pythium blight and Rhizoctonia blight on Poa trivialis, Pythium root rot on verbena.

Colletotrichum leaf spots are also a common disease problem on a wide variety of plants. Stress may or may not be involved with these situations. Sanitation and protective fungicide sprays are often recommended.

Volutella canker on hibiscus is not a commonly seen disease. The fungus produced tiny orange fruiting bodies on infected stem areas. These bodies were observable with a hand lens. As with most canker diseases, pruning is recommended. On ornamentals, Cleary's 3336 protective sprays may give some protective disease control after pruning operations are completed.

March Possibilities:
Unusually warm weather during January and February caused early bloom and spring development of many landscape and crop areas. Sporadic freezing night temperatures in February have caused cold damage on some field and landscape plantings. With woody ornamentals, watch for bark splits and leaf edge browning to occur from the time of the cold injury to about 4-10 weeks thereafter. Bark splits are not always noticed, and branch dieback noted in April-May may be related to cold injury several weeks earlier. Other diseases often reported in early spring include bacterial leaf spots on greenhouse crops.

1998 FEBRUARY DISEASES SEEN IN THE PLANT DIAGNOSTIC LAB
PLANTDISEASECOUNTY
CrinumAnthracnose (Colletotrichum)Lee
English IvyPythium Root RotCalhoun
HibiscusVolutella CankerBaldwin
HydrangeaPhytophthora & Pythium Root Rot*
Magnolia, southernColletotrichum Leaf SpotMontgomery
MaplePythium Root RotElmore
PansyCercospora Leaf SpotEscambia
PansyPythium Stem RotEscambia
* Counties are not reported for nursery and greenhouse crops.

DISEASE DESCRIPTIONS AND BRIEF CONTROL COMMENTS ON SOME COMMON DISEASES SEEN IN MARCH
PlantDiseaseDescriptionControl
AZALEABotryosphaeria Canker Sunken cracked lesions on branches. Often this canker follows cold injury or some other type of wound. Stressed plants are often involved.Sanitation.
AZALEABotrytis Petal Blight Large irregular areas of blossoms turn brown; brown areas are covered with a gray delicate webbing during humid weather.See the APMH.
AZALEACercospora Leaf Spot Roughly circular-angular brown-black spots (about 0.5 cm diam.); spots are usually associated with stressed plants.Sanitation of fallen leaves. Maintain proper fertility and watering schedules. Protective sprays of Cleary's 3336 may be applied.
AZALEAColletotrichum Leaf Spot Roughly circular brown-black leaf spots (about 0.5 cm diam.). Spots often associated with stressed plants..See Cercospora Leaf Spot.
AZALEAExobasidium Gall Blossoms and leaves develop green-pink-white fleshy galls.See the APMH; sanitation.
AZALEAOvulinia Petal Blight Small white-brown spots enlarge to become large browned areas on the blossoms.See the APMH.
AZALEAPestalotia Blight
Secondary)
Gray-white dried blotches on foliage, often along leaf edges.Sanitation.
AZALEAPhytophthora Crown
& Root Rot
Crown & roots become brown and water-soaked, then dried.See the APMH; sanitation.
AZALEARhizoctonia Aerial Blight Medium-dark brown spots or blotches on lower leaves may involve 50-100% of leaf area. Dead leaves will fall.See the APMH.
BOXWOODMacrophoma Blight-Stress During the winter, boxwood may change color and take on a reddish tint. These discolored plants sometimes develop a more serious yellowing and blight with tiny black dots scattered on yellowed leaves; cankers may develop. This is generally a problem of stressed plants. Pruning; proper maintenance.
CAMELLIAAlgal Leaf Spot (Cephaleuros)Green or green-red, slightly raised leaf spots with slightly wavy margins. Old spots have white centers.See the APMH.
CAMELLIARingspot Virus Yellow or brown rings develop on leaves. Plants may be stunted.Maintain plants with proper fertilization and water schedules.
CEDAR, RED (JUNIPER)Cedar Apple Rust Gymnosporangium Large (1-3 inch diameter), woody galls on stems develop orange, jelly-like projections (one or more inches long) which protrude from the entire surface of the gall.Remove galls before orange "fingers" develop. Apply protective fungicide sprays to apple and crabapple. See APMH.
CHERRY LAURELBacterial Leaf Spot
(Xanthomonas)
Medium to dark-brown circular or slightly irregular spots develop. As spots age, they dry and eventually the whole spot may fall out. Small, faint halos present sometimes. Sanitation; basic copper sulfate may give protective control. See Alabama Pest Management Handbook .
CHERRY LAURELCercospora Leaf Spot Irregular brown spots of variable size. Sanitation of leaves in the fall.
EUONYMUSAnthracnose (Elsinoe) Brown circular-angular lesions on leaves. See the APMH; sanitation.
GERANIUMBacterial Blight
Xanthomonas campestris pv. pelargonii)
Black, angular, water-soaked spots on leaves and stems; wilt; dieback.Sanitation. See the APMH.
GREENHOUSE CROPSBacterial Leaf SpotSmall-large, irregular, dark, wet-looking spots which often become dry in their centers and may have yellow zones or borders at their outer edges.Strict sanitation; eliminate overhead irrigation if possible; copper sprays help some; see APMH.
GREENHOUSE CROPSBotrytis BlightSee Azalea. See APMH. Decrease humidity.
GREENHOUSE CROPSDowny MildewsDiffuse yellow spots on upper leaf surfaces with corresponding areas on lower leaf surfaces showing darker color, often with tan-gray fungal growth. See the APMH for specific controls.
GREENHOUSE CROPSPhytophthora Root Rot Roots become brown, decayed, water-soaked; the outer cortex easily pulls away from the inner tissues.Sanitation. Check soil water relations and fertilizer levels. Chemical control depends on plant type.
HOSTA Pythium Crown Rot
Brown, wet, water-soaked decay at lower stem near the soil line.Sanitation; improve soil drainage; rotate away from Hosta; Subdue 2E after test treatment.
INDIAN HAWTHORNE Entomosporium Leaf SpotReddish spots with black centers.Sanitation. Protective fungicide sprays.
IRIS, BEARDEDHeterosporium Leaf Spot Brown, usually elliptical, sometimes large (1-2 cm) spots.Sanitation. Protective sprays of Cleary's 3336.
JUNIPERCedar Apple Rust
Gymnosporangium virginianae)
Spherical woody galls develop on twigs and branches; with warm wet weather, orange, jelly-like projections or fingers extend from the galls.Remove galls before they develop orange spore projections; see ANR-468.
LEYLAND CYPRESSPhomopsis Twig Canker Sunken circular or elliptical brown lesions on twigs.Sanitation; protective spray of Cleary's 3336.
LEYLAND CYPRESSCercospora Blight Blight usually starts on lower inner needles.Pruning, sanitation, protective sprays of Cleary's 3336.
LILACBacterial Leaf Spot Black, angular, water-soaked spots.See the APMH; sanitation.
LILACPythium Root Rot Roots are off-color, decayed, water-soaked.Sanitation; improve soil drainage; crop rotation.
MAGNOLIAPhyllosticta Leaf Spot Small-large (0.5-1 cm) light brown usually circular spots.See the APMH under 'Leaf Spot'.
PEAR, BRADFORDFireblight Erwinia)Black-colored dieback, blossom blight, twig-tips may have a shepherd's crook Sanitation; see APMH.
PERIWINKLEPythium Root RotRoots brown and water-soaked.See the APMH; sanitation.
PETUNIAPythium Root RotSee Periwinkle.
PETUNIAPhytophthora parasitica
Crown Rot
Cankers and blight areas develop on foliage.Sanitation. Daconil, Echo, Thalonil, and Aliette are labelled.
PHLOX (AND OTHER ORNAMENTALS)Powdery MildewsBuff or white powdery patches on leaves and stems; some distortion of new growth.Sanitation; Cleary's 3336 may be used.
PHLOX (AND OTHER ORNAMENTALS)Rhizoctonia BlightLower leaves become brown blotched with whole leaves and stems sometimes affected.Sanitation. Cleary's 3336 may be used.
PHOTINIAEntomosporium Leaf SpotDark red spots (usually 3-4 mm or 1/8 inch diam.) on upper and lower leaf surfaces. Spots often coalesce.Pruning; fungicide treatment; see Cir. ANR-392 or APMH.
PINE, LOBLOLLYFusiforme Rust
(Cronartium quercuum f. sp. fusiforme)
Rusty, powdery coating appears on the surface of fusiform (elliptical-shaped) swellings on branches and trunks. (Near-by oaks will develop small black leaf spots in late spring.). Sanitation in landscape settings; protective fungicide sprays available for nursery situations. See the APMH.
PINE SEEDLINGS, LONG LEAFRhizoctonia Root Rot Brown lesions, often shriveled, on roots.Sanitation.
PINE, VIRGINIAFusarium Pitch Canker Sunken, elliptical lesions on branches and trunks covered with pine resin.Sanitation.
PINE, VIRGINIANeedle Rust
(Coleosporium)
Cream-colored pustules (2-3 mm or 1/8 inch wide and high) develop along the edges of needles..
PRIVETCercospora Leaf Spot Large (1/4-1/2" diam.), medium brown circular or irregular spots.See the APMH; sanitation.
RED CEDARPhomopsis Dieback Tips of twigs are brown. The dieback will extend further down the twig as time progresses; canker.See the APMH; sanitation.
RHODODENDRON AZALEABotryosphaeria Canker Elongated, elliptical, sunken, brown cankers with margins that are often cracked. Sanitation.
RHODODENDRONCercospora Leaf Spot Brown spots (5-10 mm or 1/4-1/2" diam.) usually circular.Protective sprays of Cleary's 3336 or Domain. Sanitation.
ROSE, HYBRID TEANectria Canker Sunken cane lesions with some callus production around lesion edges.Sanitation. Protective fungicides labeled for black spot
THRIFT (Phlox subulatins)Anthracnose
(Colletrichum)
Brown or reddish-brown spots, blotches (1-3 mm diam.) develop. Spot coalescence.Sanitation; protective sprays of Cleary's 3336 or Domain may help.
THRIFTPhlox subulatins)Rhizoctonia Crown Rot The stem (crown) at the soil-line becomes brown, dried, and rotted.Crop rotation; possibly soil solarization..
TULIPFusarium and
Penicillium Bulb Rots
Bulbs develop sunken brown-gray dried lesions. Penicillium sporulation may occur as a blue-gray mold on the surface of the sunken rotted area.Sanitation. Bulb dips. See the APMH.
VINCA, ANNUALRhizoctonia Stem Rot Dark brown, dried, sunken lesion(s) on stems.Sanitation; remove damaged plants; Chipco 26019, Cleary's 3336, or Domain protective sprays; see APMH.
(from Jackie Mullen at the Extension Plant Pathology Lab at Auburn University)

NEW FIRE ANT BAIT PRODUCTS

Fire ant baits are the least labor intensive and often the longest lasting method of fire ant control. They all work in a similar manner:
bait = carrier + food attractant + active ingredient (insecticide or insect growth regulator). When using these products it is very important to follow all label directions carefully. Below is a summary of some of the registered uses for fire ant baits.

ACTIVE INGREDIENTCOMMERCIAL OR PUBLIC TURF AREAS; ATHLETIC FIELDS, GOLF COURSES, ETC.INDOOR USECOMMERCIAL NURSERIES
VarsityX-X
AwardX-X
AmdroX-X
Amdro ProXXX
ExtinguishX-X
DistanceXXX

(from Kathy L. Flanders, Extension Entomologist)

UPCOMING EVENTS:

April 22-24, 1999:
1999 Alabama Master Gardeners Conference.
Holiday Inn Research Park and Huntsville-Madison County Botanical Garden, Huntsville, AL.
For more information contact Mary Beth Musgrove at 334-844-5481 or mmusgrov@acesag.auburn.edu

July 22-27, 1999:
American Nursery & Landscape Association Annual Convention.
Philadelphia, PA. Contact ANLA at 202-789-2900; http://www.anla.org

July 28-31, 1999:
96th American Society for Horticultural Science.
Minneapolis Convention Center, Minneapolis, MN. Contact ASHA: 703-836-4606, Fax: 703-836-2024; e-mail: ashs@ashs.org

July 30-August 1, 1999:
SNA 99 - Southern Nurserymen's Association Researcher's Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA. Contact SNA at 770-973-9026; SNA Infoline at 770-973-4636;
http://www.sna.org

August 1-4, 1999:
International Society for Arboriculture Annual Conference. Stamford, CT. Contact ISA at 217-355-9411; http://www.ag.uiuc.edu/~isa

September 10-11, 1999:
TNA's "Tennessee America's Nursery" Trade Show and Conference.
Opryland Hotel Convention Center, Nashville, TN. Contact TNA at 931-473-3971; fax 931-473-5883; e-mail nurseryassn@blomand.net

September 23-25, 1999:
6th Biennial Southern Plant Conference.
Richmond, VA. Contact SNA at 770-973-9026; SNA Infoline at 770-973-4636; http://www.sna.org

October 3-6, 1999:
Southern Region International Plant Propagators' Society.
Mobile, AL. Contact David Morgan: 817-882-4148, SR IPPS, P.O. Box 1868, Ft. Worth, TX 76101; e-mail dmorgan@bsipublishing.com

October 8 and 9, 1999:
Middle Tennessee Nursery Association Horticulture Trade Show.
Civic Center, McMinnville, Tennessee. For more information call 931-668-7322, fax 931-668-9601; e-mail: MTNA@blomand.net
www.growit.com/MTNA>p> November 4-6, 1999:
Gulf Coast Native Plant Conference
Camp Beckwith, Fairhope, Alabama
Featuring four habitats with guided field trips. For more information contact Thayer Dodd, Conference Coordinator, at 1-888-808-3633

January 11-13, 2000:
Kentucky Landscape Industries Winter Educational Conference and Trade Show.
The Lexington Center, Lexington, KY. Contact Debbie Cain, KNLA Exec. Dir. at 502-899-3622; fax 502-899-7922

January 19-21, 2000:
Mid-AM Trade Show.
Navy Pier, Chicago, IL. Contact Don W. Sanford at 847-526-2010, fax 847-526-3993; e-mail midam@mc.net

January 29-February 2, 2000:
Southern Region American Society for Horticultural Science Annual Convention.
Lexington, KY. Contact Paul Smeal at 1107 Kentwood Drive, Blacksburg, VA 24060-5656, 540-552-4085; fax 540-953-0805; e-mail psmeal@vt.edu

February 3-6, 2000:
The Management Clinic.
Galt House, Louisville, KT. Contact ANLA at 202-789-2900; http://www.anla.org

June 1-3, 1999:
Mid-South Greenhouse Growers Conference.
Ramada Inn - Southwest Conference Center in Jackson, MS. More information will be available soon or you can contact Allen Owings, Extension Horticulturist at LSU.

July 8-12, 2000:
Ohio Florists' Association Short Course and Trade Show.
Greater Columbus Convention Center. Contact OFA at 614-487-1117; e-mail ofa@ofa.org; web: http://www.ofa.org

July 11-16, 2000:
American Nursery & Landscape Association Annual Convention.
Location TBA; contact ANLA at 202-789-2900; http://www.anla.org

July 14-18, 2000:
Ohio Florists' Association Short Course and Trade Show.
Greater Columbus Convention Center. Contact OFA at 614-487-1117; e-mail ofa@ofa.org; web: http://www.ofa.org

July 16-19, 2000:
American Society for Horticultural Science 97th International Conference.
Disney Coronado Springs Resort, Orlando, FL. Contact ASHS at 703-836-4606; fax 703-836-2024; e-mail ashs@ashs.org

August 3-6, 2000:
SNA 2000 - Southern Nurserymen's Association Researcher's Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA. Contact SNA at 770-973-9026; SNA Infoline at 770-973-4636; http://www.sna.org

August 11-18, 2000:
International Society for Arboriculture Annual Conference.
Baltimore, MD. Contact ISA at 217-355-9411; http://www.ag.uiuc.edu/~isa

September 15-16, 2000:
TNA's "Tennessee America's Nursery" Trade Show and Conference.
Opryland Hotel Convention Center, Nashville, TN. Contact TNA at931-473-3971; fax 931-473-5883; e-mail tnurseryassn@blomand.net

October 8-11, 2000:
Southern Region International Plant Propagators' Society.
Norfolk, VA. Contact David Morgan at 817-882-4148; fax 817-882-4121, SR IPPS, P.O. Box 1868, Ft. Worth, TX 76101; e-mail dmorgan@bsipublishing.com

January 27-31, 2001:
Southern Region American Society for Horticultural Science Annual Convention.
Fort Worth, TX. Contact Paul Smeal at 1107 Kentwood Drive, Blacksburg, VA 24060-5656, 540-552-4085; fax 540-953-0805, e-mail psmeal@vt.edu

August 2-5, 2001:
SNA 2001 - Southern Nurserymen's Association Researcher's Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA. Contact SNA at 770-973-9026; SNA Infoline at 770-973-4636; http://www.sna.org

October 18-21, 2001:
Southern Region International Plant Propagators' Society.
Houston, TX. Contact David Morgan at 817-882-4148; fax: 817-882-4121; SR IPPS, P.O. Box 1868, Ft. Worth, TX 76101; e-mail: dmorgan@bsipublishing.com

Send questions and comments to bfischma@acesag.auburn.edu.

Letters to Bernice Fischman - 101 Funchess Hall - Auburn University, AL 36849.