JANUARY 2003


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:

SEE YOU AT THE GULF STATES HORTICULTURAL EXPO

VARIETY TRIALS PROVIDE IMPORTANT INFORMATION

ABELIA FOR COLD CLIMATES

HOW TO PRODUCE ORNAMENTAL GRASSES

ENCOURAGING NOVEL PHOSPHORUS FERTILIZER

PLANT PATHOLOGY REPORT

UPCOMING EVENTS


SEE YOU AT THE GULF STATES HORTICULTURAL EXPO

Just a reminder that the Gulf States Horticultural Expo in Mobile is a few weeks away (January 30 - February 1). It is a great opportunity to see what is happening in the industry and to gather timely information from researchers and business people during the educational seminars. To get more information and to register on line go to http://www.gshe.org


VARIETY TRIALS PROVIDE IMPORTANT INFORMATION

The following information (provided by Joe Kemble of Auburn University) is not nursery specific but good information for those who grow beyond ornamental plants.

For those of you who grow vegetables and always wonder which are the best varieties, there is a free resource on the web that can help. It is a searchable data base (updated fall '02) which includes all vegetables grown in Alabama. The data base was compiled from variety trial information generated from Auburn's annual vegetable variety trial program and available seed catalogues. The data base is searchable by type of vegetables, performance in the trials, disease tolerance/resistance claims, and source of seeds (primary suppliers).

The URL of the site is: http://www.aces.edu/department/com_veg/trials/vegetabl.htm

Please call Joe Kemble (334-844-3050) with questions.


The information presented below comes from the Journal of Environmental Horticulture which is the scientific journal devoted to the nursery industry. This past month's edition offers some excellent practical information for many of our nursery and greenhouses. If you need more information, please let us know and we can send you a copy of the article.

ABELIA FOR COLD CLIMATES

Abelia is well suited for warm climates. Planted in a climate below -20C, stems and leaves do not adapt well. In this research project 12 taxa of Abelia were evaluated to determine stem and leaf hardiness. Also evaluated was the timing of acclimation and deacclimation during a two year period. 'John Creech' was among the hardiest and probably the best choice to be incorporated into a breeding program or landscape design if you are concerned about cold-hardiness. 'Edward Goucher' and 'Confetti' had the least hardy stems and leaves.

(from "Stem and Leaf Hardiness of 12 Abelia Taxa" by S.M. Scheiber, Carol D. Robacker, and Orville M. Lindstrom, published in J. Environ. Hort.,, December 2002).

HOW TO PRODUCE ORNAMENTAL GRASSES

Ornamental grasses have become popular and a common part of our landscape designs. They offer many landscape features: interesting form, texture, color, and visual motion and gentle sounds. Commercial growers could benefit from help with production schedules as there are many cultivars and species that behave differently in spring and fall. Researchers in this study compared spring and fall division.

Feather reedgrass produced a salable plant faster from fall divisions, and two warm season grasses, redflame miscanthus and little bluestem, also grew well and were salable the spring following fall division. Two warm season grasses, prairie dropseed and variegated Japanese silvergrass grew faster from spring divisions and were slow to grow when propagated in the fall. Spring divisions survived over-wintering all of the time regardless of species. It does not seem that grasses can be categorized into spring or fall division based only on their cool or warm season growth patterns.

The five grasses in the study (little bluestem, prairie dropseed, feather reedgrass, redflame miscanthus and variegated Japanese silvergrass) were propagated in fall and spring by plugs or field divisions into 4 inch round, #1 or #2 nursery containers. Plants were evaluated for finish date and winter survival. Three fall handled species (little bluestem, feather reedgrass, and redflame miscanthus) consistently finished as salable plants within one year. Prairie dropseed and variegated Japanese silvergrass grew faster and finished with signifcantly higher survival rates from spring divisions. Spring planted plugs of prairie dropseed and little bluestem finished within 9 weeks. The two smaller container sizes finished significantly ahead of the larger sizes.

Scientific names:
little bluestem - Schizachyrium scoparium 'Nash'
prairie dropseed - Sporobolus heterolepsis 'A. Gray'
feather reedgrass - Calamagrostis xacutiflora 'Karl Foerster'
redflame miscanthus - Miscanthus 'Purpurascens'
variegated Japanese silvergrass - Miscanthus sinensis 'Variegatus'

(from "Propagation Time Affects Winter Survival and Finishing Date for Ornamental Grasses" by Bruce A. Cunliffe and Mary Hockenberry Meyer, published in J. Environ. Hort., December 2002).

ENCOURAGING NOVEL PHOSPHORUS FERTILIZER

The nursery industry has been struggling for some time with the problems related to using slow release fertilizers in container-grown ornamental woody plants. Excess phosphorus leaching is problemmatic and causes environmental pollution and the resultant regulatory pressure from state and federal agencies. The phosphorus release from these fertilizers is dependent on time, temperature and moisture, instead of plant demand. This lack of synchronization between nutrient release and plant nutrient demand can result in periods of excess nutrient supply early in the growing season and periods of nutrient deficiency later in the growth cycle. Plant growth can be inhibited because of the phosphorus surplus which can also effect the availability of calcium and zinc to the plants.

This research focused on the use of a novel phosphorus fertilizer (A1-P) that maintains constant, low levels of phosphorus in the root zone and reduces phosphorus leaching while maintaining vigorous plant growth. Rhododendron plants grown with A1-P wilted more slowly during drought and had better root development; forsythia plants grew more quickly with or without drought. More rhododendron plants produced flowers in the first year when grown with A1-P than with conventional fertilizers.

(from "Buffered Phosphorus Fertilizer Improves Growth and Drought Tolerance of Woody Landscape Plants" by Yuan-Ji Zhang, Larry Kuhns, Jonathan P. Lynch, and Kathleeen M. Brown, published in J. Environ. Hort., December 2002).


PLANT PATHOLOGY REPORT

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

November was, for the most part, seasonably warm with temperatures ranging from the 70s (days) to the 40s-50s (nights). Rainfall was adequate to sparse in different state areas. Our plant sample numbers for November were higher than usual with 88 samples received.

Turfgrass Rhizoctonia brown patch and ring nematode problems were seen in November in several locations. Phytophthora crown and root decay of several woody landscape shrubs was commonly seen.

Cercospora leaf spot, Colletotrichum leaf spot, and black rot (Xanthomonas) were noted on collards and turnips in November and early December.

Centipede, St. Augustine, and zoysia turf samples were diagnosed with brown patch. The samples were in varying stages of decline with leaf blight and crown rot present. Rhizoctonia hyphae were seen when the samples were examined microscopically. Protective fungicide treatments were recommended as long as the grass was actively growing and temperatures were moderate.

Ring nematode damage was diagnosed on centipede and zoysia samples in central and southern areas of the state. Disease control of nematode problems is difficult. See ANR-523 for more information.

Phytophthora crown and root rots were diagnosed on arbor-vitae, boxwood, juniper, Leyland cypress, wax myrtle, windmill palm, rose, and strawberry. Phytophthora is only a problem when areas remain excessively wet for a prolonged period of time. Infection causes tissues to initially become wet, brown, and water-soaked. As tissues die, they become dried. Control requires (1) sanitation (removal of plants), (2) improved soil drainage, (3) protective fungicide drenches in certain situations of greenhouses, nurseries, and large landscape plantings.

Turnips, collards, and other crucifers are especially susceptible to Cercospora and Colletotrichum leaf spots and Xanthomonas black rot in the fall when temperatures are moderate. The Cercospora leaf spot disease appears as pale brown or cream-colored irregular or round shaped leaf spots. Colletotrichum leaf spots may be confused with Cercospora. Colletotrichum leaf spots may appear water-soaked while Cercospora spots are usually dryer in appearance. Black rot begins with V-shaped yellow lesions at leaf edges. The edge spots will become black and veins leading out of the area will become black. The black coloration of the veins is due to the presence of bacteria. Gradually the black veins (and bacteria) will spread downward from the leaf edges to the main stem. Eventually the infected plants will collapse when the stem tissues become totally rotted. See the Alabama Pest Management Handbook and fact sheet ANR-1189 for more information on these diseases and their control.

Pythium crown and root rot seedling disease was diagnosed on oats, ryegrass, and wheat. Seedling foliage was stunted and wilted. Roots were decayed and water-soaked. The usual disease control recommendation is to replant when conditions are less wet.

Bipolaris leaf spot and sheath blight were also observed on oats. Leaf spots are usually small and elongated. With severe disease, spots will coalesce. Disease control measures are usually not necessary or practical. Mild seasonal temperatures and moisture favor this disease.

NOVEMBER 2002 Plant Diseases Seen In
The Plant Diagnostic Lab at Auburn

PLANTDISEASECOUNTY
ArborvitaePhytophthora Root RotMontgomery
BoxwoodPhytophthora Crown RotMadison
CentipedeBrown Patch (Rhizoctonia)Conecuh, Elmore, Houston
Centipede 'Brown Patch (Rhizoctonia)Ring Nematode (Criconemoides)Montgomery
CollardsAnthracnose (Colletotrichum)Pike
CollardsBlack Rot (Xanthomonas)Pike
GladiolusFusarium Crown Rot*
JuniperPhytophthora Crown & Root RotMontgomery
Leyland CypressBotryosphaeria CankerMontgomery
Leyland CypressPhytophthora Root RotMontgomery
OatsBipolaris Leaf Spot/Sheath BlightBarbour
OatsPythium Crown & Root RotMarengo
Palm, WindmillPhytophthora Root RotMobile
PalmRoot-Knot Nematode (Meloidogyne)Mobile
RoseFungal CankerElmore
RosePhytophthora Root RotElmore
RyeBipolaris Lower Leaf BlightDale
RyegrassPythium BlightMarengo, Sumter
SatsumaSour Rot (Geotrichum)Baldwin
Sorghum, GrainFusarium Seed MoldDale
SoybeanAnthracnose (Colletotrichum)DeKalb
SoybeanPod & Stem Blight (Diaporthe)Shelby
St. AugustineBrown Patch (Rhizoctonia)Elmore
St. AugustineTake-All Patch (Gaeumannomyces graminis var. graminis)Shelby
StrawberryPhytophthora Root & Crown RotBlount
Sweet PotatoRhizopus Soft RotBarbour
TurnipBlack Rot (Xanthomonas)Geneva
TurnipCercospora Leaf SpotChoctaw
TurnipColletotrichum Leaf SpotCullman, Talladega
Wax MyrtleBotryosphaeria CankerMontgomery
Wax MyrtlePhytophthora Root DecayMontgomery
WheatPythium Crown & Root RotMarengo
ZoysiaBrown Patch (Rhizoctonia)Henry
ZoysiaRing Nematode (Criconemoides)Henry
ZoysiaRust (Puccinia)Henry
*Counties are not reported for greenhouse and nursery samples.

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

We received 37 samples for the month of November. Weather conditions were near normal for the month. Brown patch continued to be a very common problem especially on St. Augustinegrass. Daylily rust was found at two more locations last month. Remember to remove and destroy infected foliage this fall to reduce the risk of rust surviving the winter. Other diseases of interest included suspect aster yellows on coneflower, black root rot on pansy, rust on tall fescue, and powdery mildew on tomato.

Aster yellows causes a general yellowing and stunting of the plant similar to viral diseases. However, aster yellows is caused by a phytoplasma not a virus. Often there are other symptoms on older plants such as witches brooming, and malformed flowers with petals that are frequently abnormally green colored. This disease is spread in the field by the aster leafhopper. As with viral diseases, there is no cure for infected plants. Remove infected plants as soon as they are diagnosed to prevent spread of the disease to healthy plants. (Aster yellows is difficult disease to confirm; usually confirmation requires molecular methods of PCR.)

NOVEMBER 2002 Diseases Seen In
The Plant Diagnostic Lab in Birmingham

PLANTDISEASECOUNTY
AzaleaLace BugsJefferson
AzaleaPhytophthora Root RotJefferson
BoxwoodLeafminersJefferson
BoxwoodPythium Root Rot (Poor Drainage)Jefferson
CentipedegrassBrown PatchWalker
ConeflowerAster Yellow (Suspect)Jefferson
DaylilyRustJefferson, Madison
Fescue, TallRustJefferson
HydrangeaAnthracnose (Colletotrichum)Jefferson
HydrangeaPowdery MildewJefferson
LavenderFusarium Stem Rot/PythiumJefferson
PansyAphidsShelby
PansyBlack Root Rot (Thielaviopsis)Shelby
RoseCottony Cushion ScaleMadison
Smilax (Jackson Vine)LeafminersJefferson
St. AugustinegrassBrown PatchJefferson(3)
TomatoPowdery Mildew*
ZoysiagrassBrown PatchJefferson
*Counties are not reported for greenhouse and nursery samples.

DISEASE POSSIBILITIES FOR DECEMBER
December is usually our month of least plant samples and most paper work catch-up as well as lab inventories and re-organization. Our usual December diseases include black rot (Xanthomonas campestris) and Cercospora or Cercosporella leaf spots on crucifers in the southern sections of the state. Also, Drechslera and/or Bipolaris leaf spots are seen on small grains and forages including oats, wheat, fescue, rye and also ryegrass. Of course, greenhouse plant diseases develop every month of the year. Pansy diseases are also commonly seen, especially anthracnose and Phytophthora crown and root rot.


UPCOMING EVENTS

January 15 - 17, 2003:
Mid-AM Trade Show.
Navy Pier, Chicago, IL. Contact: Rand Baldwin at 847-526-2010, Fax 847-526-3993, e-mail mail@midam.org
URL:
http://www.midam.org

January 18 - 20, 2003:
Tennessee Nursery and Landscape Association Trade Show and Conference.
Chattanooga Convention Center, Chattanooga, TN
Phone 931-473-3951; fax 931-473-5883; email tnurseryassn@blomand.net;
URL: http://www.tnla.com

January 20 - 22, 2003:
Central Environmental Nursery Trade Show "CENTS".
Greater Columbus Convention Center, Columbus, Ohio
Contact Bill Stalter, ONLA at 800-825-5062; fax 800-860-1713; email onlagreen@aol.com;
URL: http://www.onla.org

January 30 - February 1, 2003:
2003 Gulf States Horticultural Expo.
Mobile Convention Center, Mobile, Alabama
For more information: URL - ww.gshe.org or call 334-502-7777 for more information.

January 30 - February 02, 2003:
ANLA Management Clinic.
Louisville, KY.
Contact ANLA at 202-789-2900; Fax, 202-789-1893
URL: http://www.anla.org

February 1 - 3, 2003:
Southern Region American Society for Horticultural Science Meeting.
Mobile, AL. Contact Paul Smeal, 1107 Kentwood Drive, Blacksburg, VA 24060-5656; phone 540-552-4085; fax 540-953-0805; email psmeal@vt.edu;
URL: http://www.ashs.org

July 15 - 20, 2003:
ANLA Convention & Executive Learning Retreat.
Location TBA. Contact: ANLA, 202-789-2900; Fax, 202-789-1893.
URL: http://www.anla.org

July 30-August 2, 2003:
SNA 2003- Southern Nursery Association Researcherís Conference and Trade Show.
Georgia World Congress Center, Atlanta, GA.
Contact SNA at 770-953-3311; Fax 770-953-4411; SNA Infoline, 770-953-4636.
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
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 22 - 25, 2003:
IPPS Eastern Region.
Portland, ME. Contact M. Bridgen, 26 Woodland Road, Storrs, CT 06268; phone 860-429-6818; email mbippser@neca.com

July 29 - 31, 2004:
SNA 2004 - Southern Nursery Association Researcherís 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

October 1-2, 2004:
Middle Tennessee Nursery Association Horticultural Trade Show.
McMinnville Civic Center, McMinnville, TN
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

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.