AUGUST 2003

Ken's musings:

I hope everyone had a chance to go to the SNA Trade Show this year. Bigger and Better fits! As I walked through the Show, I am always humbled by the volume of new products, rare and unusual plant introductions, pesticides, ".com" groups, irrigation and landscape innovations and other advances since last year. The industry is moving fast. If you are not reading, traveling and going to educational seminars, you will get left behind. I cannot keep up but it is fun trying.

As I get excited about the new things, I get frustrated at the things that often stump our toes that we should be avoiding. I received a sample of a container media/substrate problem recently that could have been avoided if we were more careful of changes we make. Quickly summarized, a nursery bought some very fresh, smoldering pinebark that was still composting. The grower immediately potted up several 1000 plants after mixing the fertilizer blend. The fertilizer blend itself was a problem. All the slow release N, P, and K were mixed with the micro-nutrients and lime before applying it to the hot pinebark. The different textures and sizes of the particles of the various fertility ingredients are impossible to mix evenly so when the blend was added, it could not have been uniform. Uniformity is a goal we always strive for in the nursery. We received the plants after a number of weeks in the field but were able to get a probable cause of root death and severely stunted and chlorotic plants. The low pH and heat of the composting bark probably caused a quick release of the slow release fertilizer and the composting wood and bark at low pH can contribute excessive levels of manganese. Although the high salts were gone and the manganese in the substrate was low, tissue samples showed toxic levels of manganese. The take home lesson is get your bark several months early and allow it to complete the composting process. Always take several samples from the pile for testing prior to potting. Thoroughly water and leach your plants after potting to remove possible high salts. It is great to try some new experiments but do it on a small scale. Do not change large portions of your production procedures at one time until you have done a small trial. The lost growth will never be recovered and your good intentions can come back to haunt your business and your customer relationships. If you are new to the business, get advice from your county agent or look over the shoulder of an experienced nursery producer. You know what they are doing has worked for them for a long time. Use what works and then experiment on a small scale to see how you can improve.

Some of articles below are summarized from the Journal of Enviromental Horticulture, a research journal published for the benefit of our industry. Let us know if you need more information.

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

AUBURN FALL LANDSCAPE SCHOOL

FLORICULTURE AND NURSERY CROPS YEARBOOK

RELEASE OF 'SUN VALLEY' RED MAPLE

FERTILIZER METHODS OF WINTER ANNUALS

SPRINKLE IRRIGATION WITH REUSE WATER

UTILIZATION OF NURSERY RUNOFF AND WETLAND TREATED WATER FOR IRRIGATION

THE JAPANESE BEETLE BATTLE

NITROGEN NUTRITION OF CONTAINERIZED Ternstroemia gymnanthora

PROPAGATING EVERGREENS BY STEM CUTTINGS

HERBICIDES AND NATIVE WILDFLOWER SEEDLINGS

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.


AUBURN FALL LANDSCAPE SCHOOL

Make plans to join us for our inaugural Fall Landscape School on the campus of Auburn University. We plan to offer a wide range of learning opportunities from hands-on workshops to expert seminars. We are also excited about launching the Alabama Certified Landscape Program. It is our goal to offer a program that you can enjoy as well as gain knowledge and skills to enhance landscapes and delight your clients. Sessions will include Pest Management, Water Feature Construction Workshop, Irrigation Workshop, Flooding the Night with Light. There will also be tours of the beds and turf at the Jordan-Hare Stadium as well as the Lovelace Museum and the Jule Collins Smith Museum of Art. Fall Landscape School will be held on November 5, 2003. For more information please contact Dr. Dave Williams at 334-844-3032, jdwillia@acesag.auburn.edu


FLORICULTURE AND NURSERY CROPS YEARBOOK

The following summary was published by the Economic Research Service of the US Department of Agriculture, Washington, DC. and was published on line June 18, 2003.

GREEN INDUSTRY SALES ARE FLAT
While grower sales of floriculture crops increased 1.6 percent in 2002 from 2001, nursery crop sales fell by a marginal amount. Together, floriculture and nursery crops, also known as the green industry, reached $13.8 billion in sales in 2002, up from $13.7 billion in 2001. After accounting for imports and exports, domestic consumption of floral and nursery crops is up only slightly in 2002. However, on a per-U.S.-household basis, consumption is down to $136, from $137 in 2001.

The weak U.S. economy in 2001 and 2002 is largely responsible for flat grower sales in the green industry. Although floriculture crop sales have continued to grow, albeit slowly, nursery crop sales, which are about twice the size of floriculture sales, are flat. Among floriculture crops, only bedding and garden plants and foliage plants registered sales gains, raising floral crop consumption up 1.5 percent to $5.6 billion in 2002. Cut flower imports fell in value even as import volume rose, due in part to the high exchange rate of the dollar. U.S. consumption of cut flowers has been on a downward trend, now $8 per household compared with $10 in 1999.

BEDDING AND FLOWERING PLANTS LEAD FLORICULTURE SALES
Two-thirds of the value of U.S. floriculture production in 2002 consisted of bedding and garden plants and potted flowering plants. These plants led U.S. sales growth among the six floriculture subsectors, which also include cut flowers, foliage plants, cut cultivated greens, and unfinished propagative material. In 1990, bedding-garden plants and potted flowering plants comprised only 55 percent of total U.S. floriculture production value. Their relatively faster growth over the past decade is due in part to reduced demand for domestic cut flowers and cut greens. Although demand for foliage plants continues to increase, their sales growth has been relatively slower.

Imports of flowering and bedding plants, largely from Canada, have also risen rapidly in recent years, helping consumption of floriculture crops per-U.S. household reach $52 from $32 in 1990. The largest producers of bedding and garden plants are California, Michigan, Texas, Ohio, Florida, and New York, each exceeding $100 million in sales in 2002. The production of potted flowering plants is dominated by California and Florida, whose combined sales were 36 percent of U.S. growers’ sales of potted flowering plants in 2002.

Most States produce more bedding and garden plants than any of the other floriculture products. One major exception is Florida, whose growers collectively produce and sell more foliage plants than any other State. Indeed, Florida produces almost 70 percent of total U.S. foliage plant production, which is not unlike California’s two-thirds share of U.S. cut flower production. Florida produces about four times more foliage plants than flowering or bedding plants, its next largest green product.

GROWERS IN THE SOUTH AND WEST HAVE LARGEST SALES
California, Florida, and Texas all exceeded $1 billion each in sales of green crops in 2002. Since growers in these States also sell their products in other States, green sales per-U.S. household by growers in the four largest States are also the highest among all States. Together, sales by these four States accounted for 53 percent of the total U.S. green industry output in 2002.

Growers in the Southern and Western States produced 75 percent of all green crops in 2002. However, led by Michigan and Ohio, growers in the Midwest produce and sell a relatively large portion of total U.S. bedding and garden plants. Only growers in California sell more bedding and garden plants than Michigan growers. But with respect to herbaceous perennial plants, South Carolina is the sales leader.

Growers in the Midwest generated the highest sales per acre of production area--averaging more than $104,000 in floriculture sales in 2002. This compares with $92,000 in the Northeast, $80,000 in the South, and $77,000 in the West. Individually, however, growers in Colorado claim the highest sales per acre of floriculture crops in the United States--almost $300,000 in 2002.

Florida has the largest production area for floriculture crops-- close to 18,000 acres in total--about as large as the combined growing areas of all States in the West, including California, and twice as large as the Midwest’s total production area. Although California’s total greenhouse cover is close to twice Florida’s, the latter’s share of total U.S. use of shade and temporary cover is 82 percent.

FLORICUTURE GROWERS CONTINUE TO DECLINE IN NUMBER
There were 12,717 growers of floriculture crops in the United States in 1997. In 2002, the number of growers has declined to 10,216. While the number of both small and large growers has fallen, the average sales of large growers now exceed $1 million, compared with only $46,000 for small growers. (Large growers have $100,0000 or more in annual floriculture sales at wholesale, and small growers have between $10,000 and $100,000 in annual floriculture sales.) The largest average sales are by growers in the West, followed by growers in the South. Among large growers, those in South Carolina averaged more than $2.25 million sales in 2002, the highest in the 36 surveyed States. The next highest average sales among large growers were $1.84 million in California.

As floriculture sales of large growers continue to expand, sales by small growers have been shrinking since 2000. Large growers in the West and South produce and sell about twice the crop value of their counterparts in the Midwest and Northeast. Average sales of small growers are highest in the West.

The total production area for U.S. floriculture crops in 2002 was just under 58,000 acres. This is down from 1998’s 68,500 acres of production area. About 36 percent of the production area in 2002 was under covered protection, either under greenhouses or under shade and temporary cover. The rest of the crops are grown in open fields. Southern growers, principally in Florida, have bigger production areas under cover than growers elsewhere. While growers in the West also widely employ covered protection for their crops, growers in the South use more shade and temporary cover than greenhouses with rigid structures.

About 72 percent of the U.S. production area for floriculture crops is in the Southern and Western States. And of the U.S. total area under covered protection, 75 percent is in the South and West. Plants grown under covered protection include seedlings, immature, and unfinished plants, as well as high-value plants such as orchids and other tropical flowers. The decline in the size of total production area under covered protection in recent years is due in part to flat overall sales and to increasing outsourcing of seedling and propagative material production to growers in Central America and Mexico.

Cut flowers--Almost all the major cut flowers have experienced declining sales in the past decade. Although imports have supplanted domestic-grown flowers, such as roses and orchids, the import values of carnations and chrysanthemums have also fallen. The reason behind these downward trends is the general drop in U.S. demand for cut flowers since 1997 when total cut flower supply and consumption peaked. Relatively higher priced domestic cut flowers helped shift demand toward imported cut flowers and other domestic grown floral crops. Thus, while the import share of U.S. cut flower consumption remained around 60 percent, domestic cut flower production continued to recede. U.S. growers instead shifted production toward potted flowering plants, bedding and garden plants, and foliage plants.

Bedding and garden plants--As U.S. demand for floriculture crops other than cut flowers increased in the 1990s and continued to grow in recent years, domestic production of flowering, bedding, and foliage plants responded accordingly. Although still relatively small as a share of consumption, imports of these plants have also risen sharply, especially as the dollar’s exchange rate has risen. Thus far, most of these imported plants are produced in Canada since restrictions related to plant diseases and pests largely constrain imports from other countries, especially plants with soil attached to roots. Consumption of flowering, bedding, and foliage plants is now $43 per-U.S. household, up from only $22 in 1989 and $30 in 1995.

Nursery crops--U.S. production of nursery crops was estimated at $8.9 billion in 2002, 83 percent larger than floriculture crop production. Per-household consumption was $84 for nursery crops and $52 for floriculture crops. While per-household consumption of floriculture crops continues to increase, that of nursery crops appears to have peaked in 2001. The U.S. economic recession in 2001 and weak growth in 2002 are partly responsible for the subdued demand for nursery crops, despite strong U.S. housing construction activity. Imported nursery crops, largely live plants and nursery stock, are still an insignificant fraction of U.S. nursery crop consumption at 3.3 percent. Growers in California and Texas produced 36 percent of the country’s nursery crops in 2002 based on sales of $2.1 and $1.1 billion, respectively.

U.S. green imports--Cut flower imports are 48 percent of total U.S. imported green products, which were $1.1 billion in 2002. This import share is down from 60 percent in 1996 when cut flower imports per-U.S. household were $6. Cut flower imports are now down to an average $5 per household. Imported nursery stock, bulbs, etc., on the other hand, have been expanding continuously. As recently as in 2000, these nursery crop imports were less in value than cut flower imports. In 2001, nursery crops first exceeded cut flowers in value, and are now 52 percent of total U.S. green imports.

The bulk of imported cut flowers come from Colombia, Ecuador, and the Netherlands. Colombia supplies most of the imported roses, carnations, and chrysanthemums, while Ecuador ships more roses than other cut flowers to the United States. The Netherlands is the prime source for tulips. Canada and the Netherlands supply three-quarters of U.S. nursery stock imports. Live trees and plants largely come from Canada, and bulbs of tulips, lilies, and narcissus are from the Netherlands.

U.S. imports of propagative material--unrooted cuttings and slips of plants--ballooned by 400 percent in value from 1992 to 2002. Attracted by lower production costs and favorable climate, these immature plants as well as unfinished seedlings are grown initially in Costa Rica, Guatemala, and increasingly in Mexico. After shipment into the United States, they are further grown to maturity and final sale.


RELEASE OF 'SUN VALLEY' RED MAPLE

In 1995 The U.S. National Arboretum released this cultivar to wholesale nurserymen. 'Sun Valley' comes from a controlled pollination in 1972 between 'Franksred' (female) and 'Autumn Flame' (male). This cultivar has a symmetrical, broadly columnar crown with strong upright branching. Leaves have three prominent lobes and are approximately 3.8" x 3.8". Fall color is red to red purple and lasts for about two weeks. 'Sun Valley' grows best in moist, well drained, slightly acid conditions in both sun and shade. Both wet and dry soils are tolerated.

(from "'Sun Valley' Red Maple" written by A.M. Townsend and published in the Journal of Environmental Horticulture 21(2):108-109. 2003).

FERTILIZER METHODS FOR WINTER ANNUALS

Winter-grown landscape bedding plants flourish in areas that experience mild winters. To date there has been little or no research on fertilizer recommendations for these winter-grown plants. This research indicates that method of application had little or no effect. Multiple applications of fertilizers improved foliar color, foliar nitrogen (except with snapdragon) and growth index. Controlled release fertilizers (CRF) improved foliar color and plant size compared to granular water-soluble (GWS) fertilizers. Incorporating a GWS fertilizer and topdressing a CRF provided superior foliar color and larger plants compared to other inorganically fertilized plants.

(from "Fertilization Methods Affect Growth, Color and Nitrogen Leaching of Winter Annuals in Landscape Beds" by James E. Altland, Charles H. Gilliam, James H. Edwards, Gary J. Keever, Donna C. Fare, and Jeff L. Sibley, published in the Journal of Environmental Horticulture 21(2):99-107. 2003).

SPRINKLE IRRIGATION WITH REUSE WATER

Many American communities use treated sewage effluent to irrigate golfcourses, parks, schools and nursery plants. This water has a high nutrient and total salt content. When this water is applied directly to the soil most plants can tolerate the high levels of salt. But when this reuse water is applied by overhead irrigation there is some toxicity to leaves of turfgrass and landscape plants. Landscapers and nurserymen must be aware of which species are tolerant and what irrigation strategies need to be employed to minimize this potential damage. This research demonstrated that Chinese pistache and flowering plum were more damaged than desert willow and Heritage oak when irrigated with reuse water. The intensity of damage seemed to depend upon which of the following treatments were employed: diluting the reuse water, following the reuse irrigation with a post irrigation rinse of fresh water or by pH adjusting the reuse water, aerating and passing the reuse water through a carbon filter. The most reasonable strategy is to select species relative to the irrigation methods that you plan on employing.

(from "Impact of Water Treatment on Foliar Damage of Landscape Trees Sprinkle Irrigated with Reuse Water" by D.A. Devitt, R.L. Morris, and D.S. Neuman, published in the Journal of Environmental Horticulture, 21(2):82-88. 2003).

UTILIZATION OF NURSERY RUNOFF AND WETLAND TREATED WATER FOR IRRIGATION

Growers are always looking for more efficient ways to use their resources. Drip application of single pass recycled wetland effluent or direct nursery runoff have been successfully used to drip irrigate zinnia, vinca, pansies and snapdragons in a landscape setting. Larkspur and paperwhite narcissus used for cut flower crops were also successfully irrigated in this manner. There was a reduction in the yield of sunflowers during the warm season. If, however, soluble salt levels increased to the 3.0 dS/m level then salts will need to be diluted with less saline water.

(from "Irrigating Landscape Bedding Plants and Cut Flowers with Recycled Nursery Runoff and Constructed Wetland Treated Water" by Michael Arnold, Bruce J. Lesikar, Garry V. McDonald, Donita L. Bryan, and Amit Gross, published in the Journal of Environmental Horticulture 21(2):89-98. 2003).

THE JAPANESE BEETLE BATTLE

The use of bifenthrin (Talstar 0.2G or TalstarF) as a potting mix incorporation or drench treatment can prevent the development of white grubs and black vine weevil larvae in container-grown nursery crops. Instructions on the product label guides the grower to achieve a concentration of 5-25 parts per million, a concentration which will control various soil-dwelling insects. The chemical lasts for approximately three years in the potting mix which allows for preventive control of these soil-dwelling pests for years. More than 95% mortality can be expected up to three years following the media incorporation of 10 parts per million bifenthrin and more than 99.9% larval mortality for at least three years when the media is loaded with 20 parts per million of bifenthrin.

(from "Modeling the Effectiveness of Bifenthrin for Reducing Populations of Japanese and Oriental Beetle Larvae in Nursery Containers" by Richard S. Cowles, published in the Journal of Environmental Horticulture 21(2):78-81. 2003).

NITROGEN NUTRITION OF
CONTAINERIZED Ternstroemia gymnanthera

Before this research nothing was known about the mineral nutrition requirements for this very versatile upright evergreen shrub. It is valued as a specimen plant or as part of an informal hedge in sun and shade. This research has shown that maximum growth during containerized culture can be attained by the application of ammonium nitrate at 117 mg/liter (ppm) with every irrigation.

(from "Nitrogen Nutrition of Containerized Ternstroemia gymnanthera" by Peter J. Conden, Stuart W. Warren, and Frank A. Blazich published in the Journal of Environmental Horticulture 21(2):73-77. 2003).

PROPAGATING EVERGREENS BY STEM CUTTINGS

An evergreen with a great deal of landscape potential for the southeastern United States is the Castanopsis sclerophylla. This is a medium sized, rounded evergreen tree. It is readily propagated by seed. Propagation by stem cuttings, however, would allow cloning of desirable genotypes. Stem cuttings can be rooted at over 60% when taken at the softwood stage and treated with 7500 ppm potassium salt indolebutyric acid (K-IBA).

(from "Propagation of Castanopsis scherophylla by Stem Cuttings" by Peter J. Conden and Frank A. Blazich, published in the Journal of Environmental Horticulture 21(2):61-63. 2003).

HERBICIDES AND NATIVE WILDFLOWER SEEDLINGS

When planting wildflowers it is essential to control weed growth to ensure the successful establishment of direct-seeded native wildflower and grass plantings. Weeds can substantially interfere and must be controlled. The application of Plateau herbicide was studied to determine which flowers would be injured and how severely. Flowers studied were lanceleaf coreopsis, blanketflower, standing cypress, sundial lupine, annual phlox, black-eyed susan and scarlet sage. Plateau caused only minimal stunting to annual phlox, and just slightly stunted lanceleaf coreopsis and sundial lupine. Apply Plateau to these species preemergent at rates recommended on the label for wildflower establishment and maintenance. Stunting and occasional stand thinning occured on scarlet sage, blanketflower and black-eyed susan. Increased seedling rates should be used to compensate for possible thinning of the wildflower stands.

(from "Tolerance of Native Wildflower Seedlings to Imazapic" by Jeffrey G. Norcini, James H. Aldrich, and Frank G. Martin, published in the Journal of Environmental Horticulture 21(2):68-72. 2003).

PLANT PATHOLOGY REPORT

AUBURN PLANT DISEASE REPORT - JUNE
Jackie Mullen
Extension Plant Pathology Specialist

Much of June was characterized by moderate temperatures in the 80’s and frequent or adequate rainfall, depending upon the area of the state. Our lab received 178 plant samples during the month of June.

Many of our June samples were crown or root rot diseases caused by the fungi Pythium (on Helleri holly, Rudbeckia, and Vinca minor), and Rhizoctonia (on impatiens). Brown patch (Rhizoctonia ) was seen on centipede and zoysia. In addition, Sclerotium rolfsii crown rot was observed on catharanthus and Rudbeckia. Phytophthora root rot was confirmed on dogwood.

Several problems were observed on oak including anthracnose, Actinopelte leaf spot, Inonotus root rot, and dieback. Dieback is often difficult to diagnose on a large tree. With oaks dieback may be caused by a variety of factors including canker diseases, root rot diseases, and trunk wood rot fungal diseases. These problems often occur on previously stressed trees. With oaks, two common stress factors are drought and fluctuating water tables. Either one of these situations could cause oak dieback with no involvement of fungal disease. But, these stressed trees do often become infected with stress-dependent fungal cankers, root rots, or wood rot diseases. The stress-dependent diseases we often see on oaks include Hypoxylon canker, Botryosphaeria canker, Inonotus wood rot, Armillaria root rot, Ganoderma wood and/or crown (butt) rot. Bacterial scorch (Xylella fastidiosa) or oak wilt (Ceratocytis (Ophiostoma) fagacearum) will also occur as dieback symptoms. The bacterial scorch typically will develop with initial scorch showing up on older leaves first. Oak wilt initially develops as branch wilt with interveinal yellowing of leaves on affected branches. Many of the trunk canker and wood rotting agents gain entrance to the trees via wounds. The bacterial scorch and oak wilt pathogens enter leaves or twigs usually via leaf hopper feeding and bark beetle feeding, respectively.

June 2003 Plant Diseases Seen In The Auburn Plant Diagnostic Lab
PLANTPROBLEMCOUNTY
BermudaDollar Spot (Sclerotinia homeocarpa)Cleburne
BermudaExserohilum Leaf SpotCleburne
BermudaRing Nematode Problem (Criconemoides)Tuscaloosa
CamelliaAlgal Leaf Spot (Cephaleuros)Baldwin
CedarPestalotia BlightMontgomery
CentipedeAnthracnose (Colletotrichum)Tuscaloosa
CentipedeBrown Patch (Rhizoctonia)Montgomery
Cherry, OrientalCoccomyces Leaf SpotElmore
CryptomeriaPestalotia Fungal Blight *
DaylilyBipolaris Leaf Spot/BlightMadison
DogwoodBotryosphaeria Crown RotEscambia
DogwoodPhytophthora Root RotEscambia
DogwoodPowdery MildewPike
DogwoodSpot Anthracnose (Elsinoe)Marengo, Pike
HawthornCedar Hawthorn or Cedar Quince RustPike
Holly, HelleriBotryosphaeria Crown DecayTallapoosa
Holly, HelleriPythium Root & Crown DecayTallapoosa
ImpatiensRhizoctonia Crown RotMobile
Indian HawthornEntomosporium Leaf SpotAutauga, Covington
Leyland CypressCercosporella BlightMacon, Montgomery
MapleAnthracnose (Colletotrichum)Lauderdale
MaplePhyllosticta Leaf SpotElmore
MapleXylaria polymorpha (Saprophyte)Out-of-State
MayhawCedar Quince Rust (Gymnosporangium claviceps)Cleburne
OakAnthracnose (Colletotrichum)Montgomery
Oak, WaterInonotus Root RotMontgomery
Oak, WillowActinopelte Leaf SpotLee
PecanScab (Cladosporium)Russell
PeonyBotrytis Leaf BlightEscambia
PeonyColletotrichum Leaf BlightEscambia
Pine, LoblollyColeosporium Needle RustWinston
Poplar, CarolinaCladosporium BlightBarbour
Poplar, YellowAnthracnose (Colletotrichum)Madison
RudbeckiaPythium Root Decay *
RudbeckiaSclerotium rolfsii Crown Rot *
Shamrock (Oxalis)Rust (Puccinia)Lee
SourwoodAnthracnose-Colletotrichum Branch CankersCullman
St. AugustineBrown Patch (Rhizoctonia)Dallas, Henry
St. AugustineGray Leaf Spot (Piricularia)Mobile
St. AugustineTake-All Patch (Gaeumannomyces graminis (var. graminis)Henry, Mobile
Vinca (Catharanthus)Colletotrichum Stem BlightElmore
Vinca (Catharanthus)Phytophthora nicotiana BlightElmore, Mobile, Russell
Vinca (Catharanthus)Sclerotium rolfsii Crown RotRussell
Vinca minorPythium Root DecayLee
YewPestalotia Needle BlightColbert
ZoysiaBrown Patch (Rhizoctonia)Lawrence
ZoysiaRust (Puccinia)Montgomery
*Counties are not reported for greenhouse and nursery samples.

BIRMINGHAM PLANT DISEASE REPORT - JUNE
J. Jacobi
Extension Plant Pathology Specialist

The lab received 172 samples during the month of June. Some of the problems seen last month included:Phytophthora root rot on several woody ornamentals, downy mildew on viburnum, and zonate leaf spot on hickory and maple.

Downy mildew of viburnum causes angular spots or lesions that are often bordered by leaf veins. Damaged areas are initially chlorotic, but rapidly turn brown and dry as the disease progresses. Grayish-white fungal growth may be seen on the underside of lesions. In severe cases, extensive defoliation can occur. Management options for this disease include removal of affected leaves, avoiding overhead irrigations, and application of fungicides during favorable conditions (wet weather with cool to moderate temperatures). Mancozeb (several brand names) and azoxystrobin (Heritage) are labeled for control of downy mildew.

Zonate leaf spot was another common disease seen last month. This disease is caused by the fungus, Cristulariella, and is typified by grayish-brown spots with concentric rings. The rainy conditions this spring were very favorable for disease development. In one case, an affected hickory tree was completely defoliated in less than a month. However, this same tree rapidly produced a new crop of leaves and no long-term damage should occur. Rake and remove fallen leaves. Fungicides are generally not necessary.

June 2003 Plant Diseases Seen In The Birmingham Plant Diagnostic Lab
PLANTPROBLEMCOUNTY
ArborvitaePestalotiopsis BlightJefferson
ArborvitaeSpruce Spider MitesJefferson
BarberryPhytophthora Root RotJefferson
BentgrassChemical Injury *
BentgrassPythium Root Rot *
BermudagrassBipolaris Leaf SpotJefferson
BermudagrassLow pHJefferson
BermudagrassPoor Drainage/Black LayerCullman
CentipedeAnthracnose ( Colletotrichum)Jefferson
CentipedeBrown PatchJefferson (4), Shelby
CentipedeHigh pHJefferson (2)
Cypress, LeylandPhytophthora Root RotJefferson
Cypress, LeylandSeridium CankerJefferson
DogwoodPowdery MildewShelby
DogwoodSpot AnthracnoseJefferson, Shelby
Euonymus, JapanesePowdery MildewJefferson
Fescue, TallBrown PatchJefferson
GardeniaCercospora Leaf SpotJefferson
GardeniaWhitefliesJefferson
GladiolasThripsJefferson
HickoryZonate Leaf Spot ( Cristulariella)Jefferson
Hydrangea, BigleafCercospora Leaf SpotJefferson(2)
Hydrangea, BigleafSouthern Red MiteJefferson
Hydrangea, OakleafArmillaria Root RotJefferson
Hydrangea, OakleafPhytophthora Root RotJefferson(3)
Indian HawthornEntomosporium Leaf SpotShelby
Juniper, ChineseSpider MitesJefferson(2)
Juniper, ChineseTwig Blight ( Pestalotia)Jefferson
Leyland CypressPhytophthora Root RotJefferson
Maple, JapaneseAsian Ambrosia BeetleJefferson
Maple, JapanesePhytophthora Crown RotJefferson
Maple, RedZonate Leaf Spot ( Cristulariella)Jefferson
OakJumping Oak GallsJefferson
PecanLeaf Stem Gall Aphid (Phylloxera)Jefferson
PecanPecan ShuckwormJefferson(2)
Rose, FlorabundaRoundup InjuryJefferson
SourwoodPhytophthora Root RotJefferson
St. AugustineGray Leaf Spot (Pyricularia)Jefferson
ViburnumDowny Mildew ( Plasmopara)Jefferson
ZoysiaBrown PatchJefferson(2)
ZoysiaPoor Drainage/AlgaeJefferson
ZoysiaRustJefferson(2)
ZoysiaZoysia MitesJefferson(2)
*Counties are not reported for greenhouse and nursery samples.

JULY
In July we usually continue to see our 'June'-summer diseases. programs.

Recently we received a sample of dogwood anthracnose from Russell County. This is noteworthy since most of our dogwood anthracnose has been seen in northern sections of the state where temperatures are cooler. The fungal agent of dogwood anthracnose requires temperatures in the 60-75E range with high humidity. Mountainous areas with morning fogs and shade are ideal for development and spread of this disease.

We also just recently received a few samples of southern corn leaf blight caused by Bipolaris maydis.


UPCOMING EVENTS

August 9 - 15, 2003:
2003 Horticulture Tour.
Pennsylvania
Contact Brian Hardin, Greenhouse, Nursery & Sod and Horticulture Divisions of ALFA
Phone: 334-288-3900; Fax 334-284-3957
URL:
www.alfafarmers.org

August 15 - 19, 2003:
Garden Writers Association (GWA) 55th Annual Symposium.
Indian Lakes Resort, Chicago, IL.
Contact GWA at 10210 Leatherleaf Court, Manassas, VA 20111; 703.257.1032; Fax, 703.257.0213; e-mail info@gwaa.org
URL: http://www.gwaa.org/symposium/index.html

August 21-23, 2003:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail, info@farwestshow.com;
URL: http://www.farwestshow.com

September 11-13, 2003:
The Southern Plant Conference.
Charleston, SC.
Contact Danny Summers at SNA, 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636; e-mail, danny@mail.sna.org;
URL: http://www.sna.org

September 30 - October 4, 2003:
American Society for Horticultural Science Annual Meeting and 100th Anniversary.
Providence, RI.
Contact ASHS at 703-836-4606, Fax: 703-836-2024, E-mail: ashs@ashs.org
URL: http://www.ashs.org

October 3-4, 2003:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
For more information contact Ann Halcomb by: phone: 931-668-7322; fax: 931-668-9601; e-mail: mtna@blomand.net,
http://www.mtna.com/ or http://www.southeasternnursery.com/mtna/

October 5-8, 2003:
IPPS Southern Region NA.
San Antonio, TX.
Contact: Dr. David L. Morgan, 332 Warbler Drive, Bedford, TX 76021; phone 817-577-9272; e-mail, dleemorgan@msn.com

October 8-11, 2003:
IPPS Western Region 44rd Annual Conference. Portland, OR.
Contact: Jim McConnell, Bailey Nurseries, Inc., 9855 NW Pike Road, Yamhill, OR 97148; 503-662-3244; e-mail, jim.mcconnell@baileynursery.com
URL: http://www.ipps.org/WesternNA

October 22 - 25, 2003:
IPPS Eastern Region.
Portland, ME. Contact M. Bridgen, Margot Bridgen, IPPS Executive Secretary/Treasurer, 1700 North Parish Dr., Southold, NY 11971; 631.765.9638; Fax 631.765.9648; e-mail ippser@earthlink.net

November 5, 2003:
Fall Landscape School.
Presented by the Auburn University Department of Horticulture on the Auburn University campus.
For information contact Dr. Dave Williams, jdwillia@acesag.auburn.edu or 334-844-3032.

November 6, 2003:
First Annual Henry P. Orr Memorial Golf Classic.
FarmLinks Golf Club, Fayetteville, Alabama
Deadline registration is October 23, 2003. For information contact Linda Van Dyke at 334-821-5148 or at alna@prodigy.net

January 29 - 31, 2004:
Gulf States Horticultural Expo
Mobile Convention Center, Mobile, AL
Educational program: January 29; Trade Show: January 30 - 31. For more information go to http://www.gshe.org; fax 334-502-7711; phone 334-502-7777.

July 29 - 31, 2004:
SNA 2004 - Southern Nursery Association Researcher’s Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA.
Contact: SNA 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636
URL: http://www.sna.org

August 26-28, 2004:
The Farwest Show. Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail, info@farwestshow.com;
URL: http://www.farwestshow.com

October 1-2, 2004:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
Contact Ann Halcomb, MTNA Exec. Secr., P.O. Box 822, McMinnville, TN 37111-0822; phone: 931-668-7322; fax: 931-668-9601; e-mail: mtna@blomand.net,
http://www.mtna.com/ or http://www.southeasternnursery.com/mtna/

October 3-6, 2004:
IPPS Southern Region NA
Greenville/Spartanburg, S.C.
Contact: Dr. David L. Morgan, 332 Warbler Drive, Bedford, TX 76021; phone 817-577-9272; e-mail, dleemorgan@msn.com

August 25-27, 2005:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail, info@farwestshow.com
URL: http://www.farwestshow.com

September TBA, 2005:
The Southern Plant Conference.
Louisville, Kentucky.
Contact: Matt Gardiner, KY Coordinator, 502-245-0238: e-mail, matthew624@aol.com; or Betsie Taylor, KNLA Exec. Dir., 350 Village Drive, Frankfort, KY 40601; 502-848-0055 or 800-735-9791, Fax 502-848-0032 e-mail knla@mis.net
URL: http://www.knla.org
or Danny Summers at SNA, 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636; e-mail, danny@mail.sna.org;
URL: http://www.sna.org

September 30 - October 1, 2005:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
For more information contact Ann Halcomb by: phone: 931-668-7322; fax: 931-668-9601; e-mail: mtna@blomand.net,
http://www.mtna.com/ or http://www.southeasternnursery.com/mtna/

August 24-26, 2006:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401; 503-682-5089 x 2006; Fax, 503-682-5099; e-mail, info@farwestshow.com
URL: http://www.farwestshow.com

October 6-7, 2006:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
For more information contact Ann Halcomb by: phone: 931-668-7322; fax: 931-668-9601; e-mail: mtna@blomand.net,
http://www.mtna.com/ or http://www.southeasternnursery.com/mtna/

August 23-25, 2007:
The Farwest Show.
Portland, Oregon, Oregon Convention Center.
Contact Aimee Schendel, Oregon Association of Nurserymen, 29751 SW Town Center Loop West, Wilsonville, OR 97070; 800-342-6401, 503-682-5089 x 2006; Fax, 503.682.5099; e-mail, info@farwestshow.com
URL: http://www.farwestshow.com

October 5-6, 2007:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
For more information contact Ann Halcomb by: phone: 931-668-7322; fax: 931-668-9601; e-mail: mtna@blomand.net,
http://www.mtna.com/ or http://www.southeasternnursery.com/mtna/

Send horticultural questions and comments to ktilt@acesag.auburn.edu.

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

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