SEPTEMBER 1999

Hello everyone!

I think we can all collectively exhale a sigh of relief in recognition of the fact that the worst of the summer heat is over. Drought conditions seem to still be plaguing some areas of the state and region. Surely, there will be enough rain soon.

High temperatures and no rain = tough landscape installation and maintenance

We have some student research articles and there will be more next month. Ken is doing his extension duties around the state so I will wish you all a most pleasant September, a special month, getting us ready for the fall: changing leaves, changing light.

Until next month,
Bernice Fischman


The following articles are featured in this month's Something to Grow On:

THE CONTINUING SAGA OF THE CRAPEMURDER RECOVERY PROGRAM IN DECATUR

1999 ORNAMENTALS RESEARCH REPORT NOW ON LINE

WEB SITE OF INTEREST: ENVIRONMENTAL INFORMATION PERTINENT TO AGRICULTURE

ALABAMA FRUIT AND VEGETABLE GROWERS ASSOCIATION CONFERENCE AND SHORTCOURSE

CAMELLIA PROPAGATION: THE SECRETS OF ROOTING CUTTINGS

GENETIC ENGINEERING - A POSSIBLE BOON FOR GROWERS

STUDENT PAPER: THE USE OF GROWTH REGULATORS ON MEXICAN SAGE

TRADE SHOW BOOTH TIPS

WEB SITE OF INTEREST: BOTANY HANDBOOK

STUDENT PAPER: PLANT GROWTH REGULATOR EFFECTS ON CANNA LILY

1999 GULF COAST REGIONAL NATIVE PLANT CONFERENCE

HEALTH RISKS DUE TO SPREADING SEWAGE SLUDGE ON CROPLAND

WHAT'S EATING YOUR MULCH? IT COULD BE TERMITES

WEB SITE OF INTEREST: MYCORRHIZA INFORMATION EXCHANGE

THE CASE OF THE THINNING OUT GRASS...

THE VALUE OF COCONUT COIR BASED ROOT SUBSTRATES

JACKIE MULLEN'S PLANT PATHOLOGY REPORT

UPCOMING EVENTS

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 CONTINUING SAGA OF
THE CRAPEMURDER RECOVERY PROGRAM IN DECATUR

If you remember, we began a program this spring to take some poorly pruned crapemyrtles and use a few techniques to demonstrate possible solutions to "Crapemurder". Crapemurder was the term coined by Southern Living Magazine to describe the common practice of lopping the tops off of crapemyrtle. The reasons offered for this practice include, Because….???? well, just because that is what you Do; you get more flowers? Another reason often proclaimed for the practice of pruning the trees to the ground each year is because that is the way they were displayed in northern climates. Actually, in northern climates, killing freezes bring these trees to their knees but the cold is not severe enough to kill their roots. So, they sprout from the ground each year in a bush form. People in the north are unfortunately unable to enjoy the full beauty of a southern crapemyrtle.


High Maintenance, Low Visibility = Crape Murder

Decatur, Alabama has proclaimed itself the Crapemyrtle City and has many of the streets entering the town lined with these trees. To the city leaders' credit, if they were going to adopt this title, they wanted to display them in their natural and most aesthetic southern horticultural form.

For the recovery process, we selected one of the gateways to the city on Highway 31 as a demonstration area. We wanted to demonstrate the practices of developing a single stem tree, a multi-stem tree, and the more time consuming process of creative pruning of a disfigured tree to return it to its natural form.

With the help and support of the City Grounds maintenance crew, we cut the disfigured shrubs/trees to the ground in late February. We later selected from the profusion of suckers 3 to 5 sprouts to keep. We sprayed the fresh cuts of some of the downed trees with a product called Tre-Hold, which has proven in research trials to suppress the prolific suckering that always follows this practice. We took a few trees and tried to select 3 to 5 healthy, evenly spaced canes and remove all the rest of the extra branches at ground level. This is a more time consuming practice and requires a more artistic eye. For the home gardener with a few trees, this is a nice option, but for 100's of trees within the city, it is more efficient to cut the trees to the ground and select for new canes or trunks as they emerge.


Artistic Recovery - Multi-Stem Pruning

Many spots within a city offer narrow planting spaces, such as between the sidewalk and the street. These locations require a single-trunk tree that rises above the pedestrian and car level. We took a few trees and selected one sucker to become the main trunk, which will continue to be pruned to lift the branches above the pedestrians and cars. We left a few trees as control examples without spraying the Tre-Hold to show the benefit of this product. We also demonstrated, although not intentionally, the need to spray all cut surfaces thoroughly. The chemical does not move far from the application area. You quickly find your missed spots. Latent buds sprout everywhere the Tre-Hold was not applied.


from left to right:

  • Creative multi-stem recovery and pruning
  • Cut to Ground - no Tre-Hold
  • Cut to ground - select 3-5 shoots for Crapemurder Recovery. Tre-Hold applied.
  • No Tre-Hold applied

Effects of Tre-Hold applied to pruning cuts
Single Stem form with a few suckers where
Tre-Hold spray missed
No Tre-Hold applied to cuts

There was some concern that the city would lose the flowers for the next few years but our demonstration showed that the flowers did not miss a beat.


FLOWERS ARE BACK

Crapmyrtles bloom on the current season's growth so flowers were present on most branches. Observations of the few branches that did not bloom showed that they were too vigorous and succulent to set flower buds. There are so many carbohydrates stored in the roots and too much is directed to too few buds. A similar problem occurs when too much fertilizer is applied to crapemyrtles. The new growth is again too vigorous to slow down and enter the sexual phase of the tree's life cycle.

One pruning session is not a complete cure for crapemurder. Additional removal of suckers, removal of lower branches, and thinning in the upper canopy are needed to fine tune the recovery. Application of Tre-Hold is needed after pruning if you do not want to continue to remove the sprouts that generate below the cuts.

BE PATIENT! Within three to four years, you will have a properly pruned tree that displays the beautiful bark and ample continuous blooms on the upper canopy. Your annual maintenance will be almost eliminated. Twenty years from now, your children will be thankful for your efforts to provide them with this beautiful legacy of graceful, specimen trees rather than the curse of continued expensive, high maintenance, annual crapemurder butchering to maintain a diseased, suckering, knobby, disfigured bush.

(Ken Tilt, Auburn University)

1999 ORNAMENTALS RESEARCH REPORT NOW ON LINE

A great deal of valuable research goes on at Auburn University. A new web site functions as a large compendium of some of this work, which is assembled into 3 main categories:
  1. Greenhouse Crops
  2. Insect, Disease, and Weed Control
  3. Woody Ornamentals

Authors include professors and students from Auburn University in the Departments of Horticulture, Zoology and Wildlife Sciences, Entomology and the College of Forestry. Collaborators are from other universities, the private sector and government agencies.

The URL is http://www.ag.auburn.edu:80/aaes/information/ornamentals99/index.html


WEB SITE OF INTEREST: ENVIRONMENTAL INFORMATION PERTINENT TO AGRICULTURE

The EPA and USDA, through a special partnership, have worked together and recently created "Ag Center", a new web site, with the intent of helping agriculture comply with environmental requirements. The plan is to make this into a very user friendly site to provide information to producers and others interested in regulations that impact different sectors of agriculture. The current sectors covered include animals, crops, forestry, and nurseries & greenhouses. Much more is to be added.

The URL is: http://www.epa.gov/oeca/ag/

(from James E. Hairston, Professor of Agronomy & Soils, ACES Water Quality Coordinator, Auburn University).

ALABAMA FRUIT AND VEGETABLE GROWERS ASSOCIATION CONFERENCE AND SHORTCOURSE

This year's Alabama Fruit and Vegetable Growers Association Conference and Shortcourse will be held at the Holiday Inn South in Dothan, AL from November 10-12. Some of the topics to be discussed include: History of Agriculture in the Wiregrass; Farmers Market Authority Efforts for Fruits and Vegetables; Methyl bromide alternatives research/basics of fumigation; Where to get materials; Carrot Production in the Southeast Coastal Plain; Recommendations for Managing TSWV in Tomatoes; Demonstration of Tomato IPM Practices in Alabama.

Other topics include: Potential New Crops for Alabama—Pumpkins; Historical Perspective of Plasticulture in Georgia; Nuts and Bolts: Putting a Drip System Together; How to Use Your Drip System: Irrigation Scheduling; An Alabama Commercial Watermelon Operation; plus a tour of the Wiregrass Substation complete with a demonstration of plasticulture equipment. CCA points and Pesticide points will be available. The Holiday Inn South is providing a special rate for those attending the conference ($56/night plus tax). This rate is a flat rate for a room with 1 to 4 occupants. This rate also includes a full breakfast for two people. Call 1-800-777-6611 or 334-794-8711 to make your room reservation. Be sure to tell the operator that you are with the“Alabama Fruit and Vegetable Growers Conference.”

(from Joe Kemble, Auburn University).

CAMELLIA PROPAGATION: THE SECRETS OF ROOTING CUTTINGS

Bond Nursery Corporation in east Texas has an outstanding success rate propagating camellias. Here are some of their secrets:

The best time to start root cuttings is when new growth is more that 80% hardened off. The ideal cutting is 3 or 4 inches long and has 2 or 3 leaves and 2 or 3 growth buds. Slice the butt end of the cutting on an angle and/or make a scratch line through the bark and cambium to the white pulp on one side of the cutting and treat the cut with a fungicide.

The suggested rooting medium is 80% crushed, aged pine bark mulch (2-3 years old and 3/4" mesh) and 20% clean, sharp, coarse sand. Add 25-40% more volume with perlite. Add dolomitic limestone to a pH of 6. Soil is put in well-drained trays: 10x20 36 cell trays for small leaved camellias and 24 cell trays for camellias with large leaves.

To stimulate the roots they use a root stimulator made from the following:

  • the solution approximates a .5% IBA mixed with .25% NAA in de-ionized water. IBA and NAA powder come from Research Organics Corp. in Cleveland, Ohio.
  • add Celluwet (water thickening additive from Griffin Laboratories, Valdosta, Georgia) to thicken the solution (make it viscous, like 10W motor oil) so it will adhere to the stem when it is put into the rooting medium. (Make sure you consult State Agricultural and Pesticide agencies for recommended chemicals registered by your state and follow all label instructions).

Dip the butt end in the thick solution and place to a depth of 1" in the prepared trays. Trays are put in a mist bed which receives 5-10 seconds of mist every 8-10 minutes. Or else put them in a very humid environment that is shaded and wind protected with good light intensity. Preferred rooting temperature is 65 to 75 degrees Fahrenheit. Cuttings and medium must be kept moist (not dry or over-wet).

Rooting should occur in 1 1/2 to 2 months with planting in 6 to 8 months. Three things may slow the process:

  • The cutting has formed a callus. If this happens it will take longer to root. Be patient.
  • Some just take more time.
  • If the temperature is above or below the ideal more time will be required to root.

When the cuttings appear to be growing well transfer them to larger containers, 1 or 3 gallon size. Healthy roots are white and not in a tight ball. Even if the roots don't appear abundant, but are white and healthy looking, they can be transferred. Don't mix fertilizer with your growing medium as it can kill the new plants. In one or two years you should see blooms.

It's a bad idea to "store" cuttings. They must be taken care of and nourished in order to grow into healthy plants.

(from an article on camellia propagation by Ray Bond in the July-August 1999 Nursery Notes - published by the NC Association of Nurserymen, Inc. and the NC Landscape Association, Inc.).

GENETIC ENGINEERING - A POSSIBLE BOON FOR GROWERS

USDA researchers have developed a method of genetic engineering to create dwarf varieties of existing selections. This could lead to a faster, cheaper way for plant developers to create shorter cultivars and other traits. Ralph Scorza and Richard Bell, research horticulturists at USDA's Ag. Research Service Appalachian Fruit Research Station in Kearneysville, W.Va., dwarfed Bosc pear trees by inserting genes from a bacterium. The technique works on any plant, Scorza said. (304) 725-3451.
(from Greenbeam, August 1999)

THE USE OF GROWTH REGULATORS ON MEXICAN SAGE

The production of Mexican sage (Salvia leucantha) is somewhat problematic because it can grow to between 3 and 4 feet in one growing season. A possible solution for this problem could be the use of plant growth regulators (PGRs). To date most research on height control has been conducted under greenhouse conditions with plants in small containers (4" or smaller). The object of this research project was to determine the effectiveness of PGRs under nursery and greenhouse conditions.

In the greenhouse study, all PGRs significantly reduced the growth index through 6 weeks after treatment. In the nursery study treatment effects for most of the PGRs were more transitory. Size control steadily decreased through 4 weeks after treatment with no significant growth suppression by 6 weeks after treatment.

The results of the study indicate that although PGRs have retarding effects under both greenhouse and nursery conditions, effects may be less pronounced and less persistent under nursery conditions. In a greenhouse setting, all of the PGRs provided excellent size control of Mexican Sage for a minimum of 8 weeks. Conversely, all of the PGRs reduced height at 2 weeks after treatment in a nursery setting, but two weeks later, growth suppression was much less or non-significant. By 6 weeks after treatment, all plants treated with PGRs in a nursery setting were similar in size to non-treated controls. Shorter term growth control under nursery conditions indicates the importance of crop scheduling and market timing with Mexican Sage and suggests the need for either higher PGR concentrations or multiple applications.

(From a student research paper at SNA by Stephanie E. Burnett, Gary J. Keever, J. Raymond Kessler, Jr. and Charles H. Gilliam).

HOW TO PULL SHOW-GOERS INTO YOUR TRADE SHOW BOOTH

TRADE SHOW BOOTH TIPS

  1. Use bold graphics: a message of no more than 8 words describing what you can do for someone. Company name and product are less important in drawing people in so should be smaller.

  2. Always create a separate sign that says NEW about your product. People will stop and look.

  3. Use bright colors as they get people's attention. Black lettering on orange or yellow gets much more attention than white paper. Earth tones and blues are comfortable colors but not jarring enough to get someone's attention.

  4. Photos appear to be more attention grabbing than graphics. Before and after shots are also effective.

  5. Don't stack brochures on your table as it looks like no one is picking them up. If you want to use brochures restock your short table stack often. One page handouts seems to be best, though.

  6. Make sure people can comfortably browse. Make a sign welcoming people to browse and enjoy your exhibit. Don't block your exhibit with a table that makes it difficult for people to pass by.

  7. Stand off to the side with your arms uncrossed over your chest and not in your pockets. Face the main aisle at a 45 degree angle so you don't look that imposing.

  8. Don't put give-aways out on your table as people grab them without even talking with you. Keep them on your person and give them to people you talk to as a way of expressing your appreciation.

  9. Round tables are more welcoming - do not appear to be a barrier between you and them.

  10. Use bright lighting as a way to draw people in. It is a very effective tool.

    (from an article by Dr. Allan Knonpacki, a research psychologist who specializes in assessing behavior at trade shows. It originally appeared in the Wisconsin Landscape Federation, Inc. December 1998).

    WEB SITE OF INTEREST: BOTANY HANDBOOK

    The University of Florida's CES web site has a 16 page Botany Handbook that will surely be of use to horticulture people, the general public, and particularly master gardeners as it is quite useful in plant identification. The document covers scientific names and classification, root systems, stem types, food storage organs, leaf shapes and structure, flower types and parts ID, seed, and fruit types. The URL is http://edis.ifas.ufl.edu/scripts/htmlgen.exe?body&DOCUMENT_MG012
    (from Allen Owings, Louisiana).

    STUDENT PAPER: PLANT GROWTH REGULATOR EFFECTS ON CANNA LILY

    The rather dramatic size of canna lilies makes them difficult to manage in nursery and retail settings. Canna lily species and cultivars are characterized by heights of up to five feet with leaves two feet in length and six inches in width. They bloom in mid- to late summer. Problems arise during container production due to their rapid and top-heavy growth habit. Pots blow over easily and shipping costs are increased. Plant growth regulators (PGRs) are effective in suppressing height in numerous species and may offer benefits in the production, shipping, and marketing of canna lilies. The objective of this study was to determine the effects of several rates of four PGRs on height and flowering of canna lily.

    Canna lilies were divided and repotted in a substrate consisting of 7:1 pine bark to sand medium amended with 10.7 kilograms Polyon 22-4-14, 0.9 kilograms Micromax, and 3.0 kilograms limestone per cubic meter. Plants were placed in full sun with overhead irrigation. After the plants were measured the following PGRs were applied as foliar sprays: B-Nine, Bonzi, Cutless, and Pistill.

    Results of this experiment show that vegetative and inflorescence height of canna lilies can be significantly reduced during production using Bonzi or Cutless. Height suppression was more persisent with Cutless than with Bonzi; however, plants treated with either PGR and transplanted into the landscape outgrew treatment effects within two months of planting.

    (From a paper by L.L. Bruner, G.J. Keever and C.H. Gilliam, Auburn University)

    1999 GULF COAST REGIONAL NATIVE PLANT CONFERENCE

    This conference (November 3 - November 6, 1999) has been planned to feel more like summer camp so participants are encouraged to leave their briefcases at home and pack their sneakers. You will experience the terrible, deadly beauty of the White Topped Pitcher Plant, thought by many to be one of the loveliest plants on earth; feel the grandeur of the Longleaf Pine Forest; see beach and dune flora as they live their well-adapted lives in one of the most inhospitable ecosystems in North America. Participants will also visit a classic southern swamp forest, the native home for many treasured ornamental trees and shrubs. Passionate and cordial discussions are planned as well as many social events. Call Thayer Dodd at 334-645-2222 for registration information.

    HEALTH RISKS DUE TO SPREADING SEWAGE SLUDGE ON CROPLAND

    A potential health risk exists for those living in the United States. Two Georgia researchers did a literature review on what is currently known regarding the possible risks to human health associated with the agricultural use of sewage sludge. We need to figure out how to limit sludge applications so as to avoid harmful amounts of toxic elements in produce. It is not an easy issue to address because of all the complicated variables.

    The concentration of toxic elements in sludge varies greatly. How plants uptake and store toxic elements is not universal. The individual consumption of effected crops ranges from very high to very low. The U.S. Environmental Protection Agency has decided to monitor this problem by setting limits on the accumulation of various toxic elements in agricultural soil. The limits are quite a bit higher than they are in other countries. U.S. farm soils will be allowed to accumulate concentrations of lead, mercury, cadmium, chromium, copper, nickel, selenium and zinc ranging from 10 to 100 times the pre-sludge concentrations. Dudka and Miller, from the University of Georgia, conclude in their researach that due to "the limited supply of toxicity data obtained from metals applied in sewage sludge, it is very dificult to foresee if the [EPA] approach to setting limits for metals in soils, allowing substantial increase in soil metal concentrations, will be effecive in protecting environment, food chain, and human health from adverse effects of potentially toxic metals."

    The researchers concluded that there is insufficient data to make a scientifically based judgment on the safe limits of toxic elements in farm soils. It may be the responsibility of local communities to enforce stricter regulations.

    (from HortIdeas On-Line, May 1999).

    COMPARATIVE MULCH STUDY

    Some of the findings from a recent mulch study in Florida are:
    • Most nutrient laden mulch was that derived from utility trimmings. These trimmings include a significant amount of green material but are still less than 1% nitrogen. Pine straw also provides nutrients.
    • Pine straw, pine bark,and cypress mulch are the most decomposition resistant mulches. These have significant lignin content that increases decay resistance.
    • Aromatic compounds found in almost all mulches lead to an allelopathic ("the inhibition of growth in one plant by chemicals produced by another plant") affect. Pine straw and utility trimmings have the most allelopathic affect. Both suppress weed seed germination for at least one year while other mulches only suppress seed germination for 2-3 months. No research has been done to determine the allelopathic influence of these mulches on shrubs, bedding plants, etc. in landscape beds.
    • Mulches do lower the pH of underlying soil. Utility trimmings lowered pH the least in this study, followed by cypress mulch and pine bark mulch. Pine straw mulch lowered pH significantly more than the other mulches. These results were afer one year of use and influenced the top 2-4" of soil.
    • Pine bark and cypress mulch retain original color better than other mulch materials.

    (from Allen Owings, Commercial Nursery Crop/Home Grounds Update - August 15th).

    WHAT'S EATING YOUR MULCH? IT COULD BE TERMITES!

    University of Florida researchers have conducted experiments that have shown that various kinds of organic mulching materials can be utilized as food by dark subterranean termites. These termites consumed mulches consisting of cypress, eucalyptus, pine bark, melaleuca, pine straw and mixed utility prunings. Termites could be fortifying themselves on these mulches while assaulting nearby wooden buildings. The U.S. Forest Service manual on controlling insects that attack wood cautions that when construction of a new home is done, any "piece of wood that can be picked up between the tines of a common garden rake should be removed" to avoid attracting termites. Thick, well watered mulch is a great all you can eat buffet for these destructive insects.
    (HortIdeas On-line, May 1999 - from an article by Jacob B. Huffman, R. Jeffery English, and Weste Osbrink, "Will Subterranean Termites Consume Landscape Mulches?", published in the Journal of Arboricultre, May 1999)

    WEB SITE OF INTEREST: MYCORRHIZA INFORMATION EXCHANGE

    This web site has information, links, articles, bibliographies, images, news and sources of mycorrhizal inoculants.

    The address is http://mycorrhiza.ag.utk.edu


    THE CASE OF THE THINNING OUT GRASS...

    When you look out onto your lawn are you not taken with the emerald green beauty of it? The main culprit for thinning grass is shade. All turfgrasses require sunlight to grow. If the sun does not directly hit the ground, consider shade tolerant ornamental, or ground covers or mulch. Soil compaction is the second most frequent cause of stand loss. To check for this problem, force a six inch bladed knife or screwdriver into moist soil. You should be able to push the blade in with your thumb over the head of the handle. Compare its pressure to a known softer soil.

    Poor soil fertility is also a potential problem. Some grasses can survive in pH of 4.9 while others can't. If you can't or won't change the pH, you will have to change your grass. Don't think that centipede likes very acid soil. It does well at 6.5 and has been known to survive at 8. Grass is kind of 'growing or going'. If you don't have a moderate level of fertility (N, P, K) it will be going.

    And there is also the problem of rings that develop around the base of trees. Loosen the soil/thatch mat and apply Prostar fungicide as directed for a slow improvememt. There is the stress of wear. Some grass doesn't wear well and will get too compact. Wear-tolerant selections are Bermudagrass or St. Augustinegrass.

    Lastly, consider the stress of improper mowing which involves cutting it too close or too frequently. Don't take more than the top 1/3 off at any one time.

    (from Allen Owings, Commercial Nursery Crop/Home Grounds Update, Louisiana, August 1999).

    THE VALUE OF COCONUT COIR BASED ROOT SUBSTRATES

    Adding 60% or more coir to a perlite and sphagnum peat growing mix inoculated with soybean-attacking Phytophthora megasperma prevented disease symptoms on soybean seedlings. Without coir, more than half of the seedlings died.
    (from Michael R. Evans, Department of Horticulture, Iowa State University, Ames, IA - published in HortIdeas On-line, May 1999)


    JACKIE MULLEN'S PLANT PATHOLOGY REPORT

    MONTHLY PLANT PROBLEM REPORT
    FROM THE PLANT DIAGNOSTIC LAB - JULY

    As usual, July was a busy month in the clinic. Diseases of ornamentals and turf were numerous. We saw unusual leaf spot disease of dogwood. The spot somewhat resembled dogwood anthracnose, but the associated fungal spores were that of a Phomopsis-type fungus, not Discula.

    Black root rot (Thielaviopsis) was identified on Helleri holly. It is not unusual to find this disease on Helleri holly, but we do not usually see active black root rot during the high heat of the summer. The fungus was probably just trying to 'hold on' until temperatures drop this fall. Black root rot is identified by the presence of numerous black spores on the surface of roots.

    A diagnosis of Pythium is usually significant on herbaceous plants. Pythium root rot diagnosis on woody plants is often associated with other problems. In all cases, Pythium development depends upon prolonged wet conditions. Pythium is known as a 'root nibbler', damaging small feeder roots.

    A morningglory sample was received with rust (Puccinia) and white rust (Albugo). White rust is not commonly encountered. The fungus develops white leaf or stem pustules that are composed of chains of spores. This fungus is related to Pythium and Phytophthora, and moisture is required for disease development. Sanitation is important for disease control. Protective chemicals recommended depend upon the specific crop.

    In Mobile, John Olive reported a Phytophthora stem rot on a mature English ivy vine. He identified this disease on the basis of culture results. John speculated that it may be Phytophthora which has been causing other old established English ivy vines to die. In an azalea situation, John reported isolating a Cylindrocladium species. This fungus is known to cause a crown rot of azaleas. The best way to diagnose this disease is usually by culture isolation.

    DISEASES SEEN IN THE PLANT DIAGNOSTIC LAB IN JULY
    PLANT DISEASE COUNTY
    Boxwood Phomopsis Leaf Blight Cullman
    Boxwood Volutella Blight Calhoun
    Daylily Anthracnose (Colletotrichum) Elmore
    Dogwood Possible Phomopsis Leaf Spot Pike
    Dogwood Pythium-Phytopthora Root Rot Dallas
    Gardenia Phytophthora Montgomery
    Holly, Helleri Black Root Rot (Thielaviopsis) Madison
    Hydrangea Fusarium Crown Rot Lee
    Hydrangea Phytophthora Root & Crown Rot Lee
    Hydrangea Phythium Root Rot Elmore
    Juniper, Shore Phythium Root Rot Butler
    Lavender Phythium Root Rot Elmore
    Liriope Root-Knot nematode (Meloidogyne) Tallapoosa
    Magnolia, Japanese Powdery Mildew Pike
    Maple, Red Anthracnose (Colletotrichum)Elmore
    Maple, Red Phyllosticta Leaf Spot Elmore
    Maple, Silver Anthracnose (Colletotrichum)Coffee
    Morning Glory Rust (Puccinia) Cullman
    Morning Glory White Rust (Albugo) Cullman
    Periwinkle Phytophthora Blight Covington, Geneva
    Petunia Phytophthora Blight & Root Rot Calhoun
    Rose Botrytis Blossom Blight Lawrence
    Sycamore Powdery Mildew Montgomery
    Sycamore Alternaria Leaf Spot Montgomery

    Disease Possibilities For August

    Many of the same diseases of vegetables and ornamentals are problems throughout the summer. The disease lists for June and July are still relevant.

    August will probably see an increase in the number of fungal leaf spot diseases on a variety of crops, especially shade trees. Often, these spots occur on trees that are experiencing some type of stress including nutritional or water stresses. Alternaria, Cercospora, Septoria, phyllosticta, and a variety of anthracnose fungi are some of the many fungi seen on trees in the late summer and early fall. Leaf spot diseases developing at this time of year on trees are generally of no concern. Advise clients to collect and destroy fallen leaves this fall.

    In August, bacterial scorch disease may become evident on infected sycamore, elm, maple (red), oaks (oaks in the red and black group: pin oak, southern red oak, laurel oak, water oak) and mulberry. Symptoms include leaf edge scorch on lower branches which will slowly spread upward in the tree canopy during the following 2-5 years. Scorched foliage will develop branch dieback, usually the following year. This disease is caused by the bacteria Xylella which is believed to be transmitted by leaf hoppers. The bacteria cause xylem plugging. Tree removal is the only control recommendation.

    For specific disease control recommendations, see the Alabama Pest Management Handbook. Also remember that sanitation is a necesary component of most disease control programs.

    PLANTDISEASEDESCRIPTIONCONTROL
    AJUGASclerotium rolfsii
    Crown Rot
    Stems collapse at soil line; a white mold with brown mustard-seed sized sclerotia present.Sanitation; solarization.
    AUCUBABotryosphaeria
    Canker (Blotch)
    Black, large irregular lesions on leaves and stems; dieback beyond cankers.Sanitation; Cleary's 3336, Domain, or benomyl labelled for ornamentals.
    AUCUBAHelminthosporium
    Leaf Spot
    Brown, elongate leaf lesion.Sanitation; Cleary's 3336.
    AZALEAPhytophthora
    Crown/Root Rot
    Crowns/roots become brown and wet or water-soaked.See the Alabama Pest Management Handbook.
    BEGONIAPythium Root Rot
    Rhizoctonia/Fusarium
    Lower Stem/Root Rot
    Lower stem brown and decayed.See the Alabama Pest Management Handbook.
    CHRYSANTHEMUMBacterial Leaf Spot
    (Pseudomonas)
    Dark brown/black, small (2-4 mm diam.), angular spots; sometimes with water-soaked edges.Sanitation.
    CHRYSANTHEMUMBotrytis BlightBrown spots, blotches.See the Alabama Pest Management Handbook.
    CHRYSANTHEMUMFusarium WiltYellowing/wilt of leaves, beginning at the bottom of the plant and moving upward.Sanitation; rotation for 7-10 years or solarization.
    CHRYSANTHEMUMPythium Root RotRoots become brown and water-soaked.Sanitation; protective fungicide drenches of Captan, Subdue, or Banol; solarization or crop rotation.
    COLEUSPhytophthora Crown RotRoots become brown and water-soaked.Sanitation.
    CRABAPPLEScab (Venturia)Olive-brown circular, slightly raised spots (4-5 mm diam.) develop on leaves and fruit.See Alabama Pest Management Handbook.
    DAISY, GERBERAPhytophthora Leaf
    Blight/Crown Rot
    Leaves develop brown blotches; lower stem develop brown lesions; plants collapse.See the Alabama Pest Management Handbook.
    DAYLILYSouthern Blight
    (Sclerotium rolfsii)
    A wet rot at soil line; sometimes a white fluffy mat of fungus at soil line.Sanitation; solarization.
    DOGWOODCercospora Leaf SpotLeaf spot on lower leaves of tree; angular to irregular leaf spots (2-6 mm) which are light brown or gray in the center and dark brown or purple on borders.Sanitation.
    DOGWOODPowdery Mildew
    (Phyllactinia)
    Powdery white dusting on leaves; foliage distortion and death.Sanitation in the fall; see Alabama Pest Management Handbook.
    DOGWOODSeptoria Leaf SpotLeaf spots on lower leaves of tree; angular to irregular tan or brown spots (2-6 mm) sometimes with faint yellow halos.Sanitation.
    DOGWOODSpot AnthracnoseTiny red spots on flowers and leaves.Sanitation in fall; see Alabama Pest Management Handbook.
    EUONYMUSAnthracnose
    (Colletotrichum)
    Small, whitish spots (1/16 in. diam.) on foliage.Recommended fungicide sprays. See Alabama Pest Management Handbook.
    FERNRhizoctonia Root RotDark brown, dried,decayed roots.Sanitation; see the Alabama Pest Management Handbook.
    FORSYTHIAAnthracnoseBrown, leaf spots/blotches.Sanitation; see the Alabama Pest Management Handbook.
    FORSYTHIAFusarium Crown RotBrown, dried, decayed lower stem.Sanitation; crop rotation.
    HOLLY, JAPANESEPhytophthora Root RotRoots become brown and water-soaked; plants become yellowed with dieback.See the Alabama Pest Management Handbook.
    HOSTAWhite Mold
    (Sclerotium rolfsii)
    Lower trunk or stem is rotted and generally soft and limp.Sanitation; possibly solarization.
    HYDRANGEACercospora Leaf SpotBrown circular or angular leaf spots. Sanitation; See Alabama Pest Management Handbook.
    HYDRANGEAPythium Crown/Root
    Rot
    Wet, water-soaked brown lesions on crown and roots.See Alabama Pest Management Handbook.
    IMPATIENSRhizoctonia Crown
    and Root Rot
    Crown and roots become brown and dry rotted. Sanitation; solarization may help.
    IMPATIENSPhytophthora Root RotWet, water-soaked brown lesions on roots. See Alabama Pest Management Handbook.
    IVY, ENGLISHColletotrichum Leaf SpotBrown leaf spots that are circular or irregular.See the Alabama Pest Management Handbook.
    IVY, ENGLISHPhomopsis CankerBrown, gray lesions on stems; dieback.Sanitation; Cleary's or benomyl protective sprays.
    IVY, ENGLISHPhytophthora Root RotRoots become brown and water-soaked.See the Alabama Pest Management Handbook.
    JUNIPERPhytophthora Root RotSee Holly, Japanese.See Holly, Japanese.
    JUNIPERPestalotiopsis Needle
    Blight
    Needles turn brown in patchy areas on branches.Sanitation. See Alabama Pest Management Handbook; avoid stress.
    MAPLEAnthracnose
    (Kabatiella)
    Small-large brown blotches develop on leaves, often folllowing along veins and/or leaf edges.See the Alabama Pest Management Handbook.
    MAPLEPhyllosticta Leaf SpotSmall (4-8 mm diam.) leaf spots develop with brown-purple borders and brown-cream centers.See the Alabama Pest Management Handbook, under 'Leaf Spot'.
    SUGAR, MAPLEMonastichella
    hysteroidea
    Leaf Spot
    Brown irregular spots.Sanitation.
    MARIGOLDAlternaria Leaf SpotBlack irregular spots 0.5-2 mm diameter. When spots are numerous, plant death may result.See Alabama Pest Management Handbook, under 'Leaf Spot'.
    MONDOGRASS Anthracnose
    (Colletotrichum)
    Gray, brown spots on leaves.Sanitation. See Alabama Pest Management Handbook.
    OAKAnthracnose(Apiognomonia) Small to large brown blotches develop on leaves, often following along veins and/or leaf edges.Sanitation; See Alabama Pest Management Handbook for small oak trees.
    OAKBacterial Scorch
    Disease (Xylella)
    Leaf edge turns brown in scatttered locations in tree; gradual dieback over 2-3 years).---
    OAKOak Leaf Blister
    (Taphrina)
    Light brown leaf spots that are circular and concave-convex.Sanitation. See the Alabama Pest Management Handbook.
    PANSYPythium Root Rot Roots become brown and water-soaked; plants become yellowed and finally die.See the Alabama Pest Management Handbook.
    PERIWINKLEAnthracnose
    (Colletotrichum)
    Brown, sunken cankers on stem sections.Cleary's 3336, Domain, or WP benomyl; Sanitation.
    PERIWINKLEPhomopsis BlightBrown, sunken cankers on stem sections.Sanitation; Cleary's 3336, Domain or benomyl WP labelled for ornamentals.
    PERIWINKLEPhytophthora Aerial
    Blight
    Dark brown lesions appear on stems; dieback.Sanitation; Aliette.
    PERIWINKLEPhytophthora Root RotRoots become dark brown, decayed and water-soaked; foliage shows yellowing/dieback. Sanitation; solarization.
    PERIWINKLERhizoctonia Aerial BlightLower stems and leaves become browned and dry-rotted. Some mycelial webbing may occur. Whole plants will eventually die.Sanitation. Protective sprays of Cleary's 3336, Domain, or a benomyl WP labelled for ornamentals.
    PERIWINKLERhizoctonia/Fusarium
    Crown Root Rot
    Dried, brown lesions on lower stem and roots.Cleary's drenches will help provide some protection.
    PINE, VIRGINIAFusarium Pitch CankerSunken lesions that ooze sap.Sanitation.
    PINE, VIRGINIALophodermium
    (Ploioderma) Needle
    Cast
    Last year's needles become spotted and browned; eventually they drop. Needles have tiny football-shaped, hard black bodies scattered over their surfaces.See the Alabama Pest Management Handbook.
    PINE, VIRGINIARhizosphaeria Needle,
    Twig Blight (Suspect
    Stress Related)
    Needles and twigs become brown and dead.Apply Bravo 720 at rate of 5 1/2 pints per 100 gallons or Bravo 500 at 8 pts. per 100 gallons after shearing when growth is 1/2 inch and again when new growth is 2 inches long..
    POINSETTIABacterial Stem Rot
    (Erwinia)
    Lower stem becomes blackened and rotted; usually occurs on small plants.Sanitation.
    POINSETTIAPythium Root RotRoots water-soaked, decayed.Sanitation; protective drenches fungicide; see Alabama Pest Management Handbook.
    POPLARAlternaria Leaf SpotBrown, irregular spots (8-15 mm diam.) develop on leaves.Sanitation. Chemical treatment not usually recommended.
    RED CEDARPhomopsis BlightTips of branches become brown with damage spreading into the lower sections of the branches.See the Alabama Pest Management Handbook.
    ROSEAerial Blight
    (Rhizoctonia)
    Brown, irregular blotches on leaves.Sanitation; Cleary's 3336 would give protective control.
    VINCA MINORAlternaria Leaf SpotDark brown angular leaf spots; leaf blight.Sanitation. Chipco 26019.
    VINCA MINORRhizoctonia Aerial BlightLeaves or stems become blighted, spotted.Sanitation; Cleary's or benomyl protective treatments.
    WISTERIAPhomopsis Stem BlightDieback and brown, dried sunken lesions.Sanitation; Cleary's 3336.


    UPCOMING EVENTS

    Alabama Certified Nursery Professional Course
    August 31-September 3, 1999:
    160 Funchess Hall, Auburn University, AL.
    For more information contact Linda Van Dyke at P.O. Box 9, Auburn, AL 36831-0009; phone 334-821-5148; fax 334-821-9111.

    1999 National Urban Forest Conference: Building Cities of Green.
    Seattle, Washington. Contact Dan DeWald: 425-452-6048.

    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 15-18, 1999:
    Eastern Region International Plant Propagators' Society Annual Meeting.
    Minneapolis, MN. Contact Margot Bridgen, 26 Woodland Road, Storrs, CT 06268. Phone 860-429-6818; Fax 860-429-6665

    September 17-19, 1999:
    Alabama Christmas Tree Association Annual Meeting
    The Quality Inn Beachside Resort Hotel, Gulf Shores, AL. Contact Ken Tilt @334-844-5484; email ktilt@acesag.auburn.edu

    September 17-18, 1999:
    Tennessee Nursery & Landscape Association "TENNESSEE AMERICA'S NURSERY" 23rd Annual Trade Show and Conf.
    Opryland Hotel & Conv. Ctr., Nashville, TN.
    E-mail Tnurseryassn@blomand.net;
    www.tnla.com; Phone 931-473-3951; Fax 931-473-5883.

    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 1, 1999:
    Ornamental Horticulture Open House at the University of Georgia, Athens, GA
    Tour will be 9 a.m. to 4 p.m. For more information phone 706-542-2861. Fee is $20 before 9/24 and $25 after 9/24.

    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 Ann Halcomb, Exec. Sec., at 931-668-7322, fax 931-668-9601; e-mail: MTNA@blomand.net
    http://www.growit.com/MTNA

    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 1-334-645-2222.

    November 10-12, 1999:
    1999 Alabama Fruit and Vegetable Growers Conference.
    Holiday Inn South, Dothan, AL.
    For more information e-mail: Joe Kemble (jkemble@acesag.auburn.edu) or Arlie Powell (apowell@acesag.auburn.edu).

    November 13-16, 1999:
    ALCA Landscape and Ground Maintenance Conference.
    Baltimore, Maryland. Contact ALCA at 800-395-2522. http://www.alca.org

    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

    March 18, 2000 - September 17, 2000:
    Japan Flora 2000 'Communication Between Man and Nature'.
    Awaji Island, Japan. See http://web.pref.hyogo.jp/jpnflora/english/index.htm or Meg VanSchoorl at MVANSCHOOR@agr.wa.gov

    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 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 Researchers' Conference and Trade Show.
    Georgia World Congress Center, Atlanta, GA. Contact SNA at 770-973-9026; SNA Infoline at 770-973-4636; 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 1-4, 2000:
    Eastern Region International Plant Propagators' Society Annual Meeting.
    Hyatt Regency Oak Brook, Chicago, IL. Contact Margot Bridgen, 26 Woodland Road, Storrs, CT 06268; phone 860-429-6818; e-mail mbippser@neca.com

    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

    January 27 - January 31, 2001:
    Southern Region American Society for Horticultural Science Annual Convention.
    Fort Worth, TX. Contact Paul Smeal, 1107 Kentwood Drive, Blacksburg, VA 24065-5656; phone 540-552-4085; fax 540-953-0805; e-mail: psmeal@vt.edu

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

    September 30 - October 3, 2001:
    Eastern Region International Plant Propagators' Society Annual Meeting.
    Lexington, KY. Contact Margot Bridgen, 26 Woodland Road, Storrs, CT 06268; phone 860-429-6818; e-mail mbippser@neca.com

    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.