FEBRUARY 2003

I caught the fragrance of winter honeysuckle yesterday. That has been my call to action for spring for a number of years. We are just finishing a Great Gulf States Trade Show and Seminars. As always, Linda VanDyke and the Board of the Trade Show along with the 3 State Nursery Specialists, Tilt, Owens and Tatum welcome and appreciate your comments, good and bad. It is time for follow-up from the Trade Show. Make your contacts to people who showed interest at your booths and send thank you notes to the companies that were so kind as to host us throughout the show, read through the notes from the educational sessions and pick out a few things to incorporate in your business. As your monthly reminder send a surprise gift or thank you note to those loyal customers that have supported your family and the people you employ. On the work side, have you ordered all your herbicides, liners and potting supplies? The weeds are coming. Get out your preemergent herbicides between loropetalum and forsythia bloom. If you are in the retail business, don't let an early spring day catch you looking. Clean up and be ready for the people who have survived another long, freezing 6 weeks of winter in Alabama. I think after 4 weeks, I have suffered enough and I am ready for daffodils, robins, and of course Alabama Azaleas. Have a great month!

I want to start off the newsletter with an article from Mark Halcomb, area nursery specialist for middle Tennessee. We steal freely in Extension from each other because we are "Gov'mnt Workers" and all serve the same people. There is no reason to duplicate efforts when someone else has already done a good job. Thanks to Mark Halcomb for his information on Asian Ambrosia Beetle (AAB). It is timely because we are doing an on-farm demonstration beginning this week looking at which traps are best for detecting AAB and looking at several chemicals and spray intervals and evaluating their effectiveness. Our goal is to continue to utilize the technology of the internet to keep you up to date, real time, on the progress of this study and others. Look for updates next month on setting the traps, spraying and a log of our efforts and sources of supplies and equipment. Send in your experiences if you have some thoughts to contribute.

And ..... Oh! Oh! Oh!..... another spring and the Azalea Capital of the World, Alabama, will be looking at the continued testing by Drs. Keever and Gilliam of about 900 cultivars of azaleas to help spark a renewal of great azaleas for the garden from Alabama nurseries. Every garden should have 100 or so cultivars. They are evaluating flowering, hardiness, pest resistance as well as how well they grow in a nursery container situation. The field trials are in Camp Hill, Alabama and the container research is being conducted at the Mobile Ornamental Research Center. Follow this research on line as well as other exciting research at Auburn. I have gotten excited and ready to charge into my day just thinking about what is waiting to bloom around the corner. Have a nice day!

Ken


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:

HOW TO MANAGE AMBROSIA BEETLES

AN IMPROVED PURPLE PASSION PLANT - FOR A WHILE

ANTITRANSPIRANT TREATMENTS AND WHETHER THEY WORK

THE WEED THAT ATE THE SOUTH HEADS NORTH

NEW GROUP WILL KEEP VIRGINIA GREEN

REMEMBER LEWIS AND CLARK

GREENING ROOFTOPS

PLANT PATHOLOGY REPORT

UPCOMING EVENTS


HOW TO MANAGE AMBROSIA BEETLES

by Mark Halcomb

Ambrosia beetle attacks have been sporadic, unpredictable and extremely costly to a few local producers over recent years. Weakened or stressed plants are attacked. They have killed cherry, chestnut, hydrangea, lilac, red maple cultivars, especially October Glory, weeping mulberry, and redbud locally.

Adult beetles bore into the wood and form a gallery, which the female inoculates with an ambrosia fungus to feed herself and her larvae. Toothpick-like filaments composed of frass (excrement and sawdust) protrude from the holes several inches. Wind and rain will remove these telltale signs. Attacked trees usually die. The time to prevent damage is prior to the adult boring into the tree.

The annual trigger for ambrosia beetle activity is generally one to three consecutive warm/sunny days. Ambrosia beetles have been trapped in Warren County as early as February during mild winters but typically not before late March with peak flights occurring in April. The peak flight period may vary by several weeks among different years. Ambrosia beetles overwinter as adults, so a flush of flight activity can occur as soon as the weather becomes suitable.

Early detection of ambrosia beetle activity is the key to successful management. Traps are an essential tool as an early warning system. Ambrosia beetles begin attacking trees as they appear in traps. Therefore, beetles in the trap are a signal to spray ASAP.

The closer spray treatments can be timed to initial beetle activity, the greater the likelihood that sufficient pesticide residues will be present on the tree surface to kill or repel ambrosia beetles. Thorough wetting of the trunk is needed to prevent ambrosia beetles from boring into the plant. The effectiveness of air blast sprayers for delivery of sufficient pesticide residues to tree trunks, is questionable at this time.

Permethrin-based insecticides (Ambush, Astro, Pounce, Tempo) have been the only effective products for preventing Asian ambrosia beetle attacks. Ambush and Pounce are restricted use pesticides.

There is no way to predict in advance which plants will be attacked by ambrosia beetles. Trees that have not broken bud are at the greatest risk of ambrosia beetle attack.

Recommendations vary on whether infested plants should be promptly removed and destroyed. Plants that are infested with ambrosia beetles are highly attractive to other ambrosia beetles. Therefore, some authorities recommend leaving infested plants to draw the beetles away from non-infested stock (i.e., trap crop).

In one study, leaving infested plants in nursery blocks did not increase the risk of attack on adjacent plants. However, plants that are heavily attacked in containers, should be moved to the outer edges of the main block to draw beetles away from healthy plants. When trees are no longer vulnerable to ambrosia beetle attack (after bud break), all infested plant material should be burned before mid-May, before the next generation emerges. Ambrosia beetles can continue to emerge from pruned branches or plants thrown into a gully, so burning is the best method to destroy the insects.

A variety of traps can be used to monitor ambrosia beetle activity. Twenty to sixty dollar traps may be purchased or made from plastic drinking cups, soft drink bottles or by modifying a Japanese Beetle trap.

An attractant will be required to lure the beetles to the trap. Ethyl alcohol (ethanol) is the best bait for these beetles. Ethanol can be obtained from liquor stores (use pure grain alcohol) or paint stores (sold as denatured to prevent consumption). The alcohol should be diluted 7 parts alcohol to 3 parts water (7 cups alcohol to 3 cups water). Do not use other alcohols like isopropyl (rubbing) alcohol, because they will not attract ambrosia beetles.

Alcohol dispensers are used to release the ethanol slowly over time. A plastic pill bottle or film canister can be used to make a homemade ethanol dispenser (hence referred to as the Bottle-Type Lure). Drill a small hole (about 1/4 inch diameter) in the lid of the bottle and insert a cotton rope wick into the ethanol. Be sure the wick is completely wet so that ethanol will be drawn (absorbed) up the wick to evaporate into the air. Check the lure periodically to insure that all the ethanol does not evaporate from the container.

A killing agent in the bottom of the trap will prevent escapes. Drowning solutions placed in the trap collection container can be made from soapy water or non-toxic propylene glycol (environmentally friendly antifreeze).

Traps should be placed near expected ambrosia beetle habitats, woods adjacent to nursery crops. Place the traps about 2 to 3 feet above the ground. A single trap placed in the right location can provide a great deal of information about ambrosia beetle activity on your property. However, until you have gained personal experience with the most effective trap sites on your property, we would recommend several traps be used. A good pattern might be one trap on the north, east, south, and west sides of the crop. Check traps daily from mid-February through April. A trap can catch several hundred beetles in only a few hours when beetle flights begin. Insecticide treatments should begin as soon as beetle activity is detected and continue at 10-14 day intervals until trees break dormancy. Asian ambrosia beetles are reported to fly at dusk, so a good time to check traps might be right after dark. The best indicator that an ambrosia beetle flight has begun will be large numbers of small beetles suddenly showing up in the trap.


AN IMPROVED PURPLE PASSION PLANT - FOR A WHILE

Purple Passion Plant (Gynura aurantiaca) has been used in the industry as an ornmental foliage plant because its leaves are covered with tiny vivid purple hairs that give it a rich, colorful glow. It is easily grown from cuttings and used in hanging baskets and in containers. The problem with this plant is that the scent of the flowers is offensive and if the plant gets sufficient sun and is watered and fertilized regularly, it takes on a leggy, unattractive appearance. To counteract those problems, this research set about trying to determine if the use of plant growth regulators would suppress the flowering and excessive growth thereby improving its overall quality.

Florel (ethephon) was applied twice in March at two-week intervals. The results were suppressed flowering and enhanced lateral shoot growth which produced more compact plants whose aesthetic appearance was greatly improved. The foliar application of A-Rest, B-Nine, Bonzi, or Cycocel either did not improve the plant or was detrimental. All plants, no matter what growth regulators were used, after they were cut back, grew well and flowered the next spring which suggests that no residual effects on plant growth and development were observed.

(from "Ethephon Suppresses Flowering and Improves the Aesthetic Value of Purple Passion Plant (Gynura aurantiaca)" by Jianjun Chen, Richard J. Henny, and Russell D. Caldwell, published in J. Environ. Hort., December 2002).

ANTITRANSPIRANT TREATMENTS AND WHETHER THEY WORK

Tissue and embryo culturing are techniques that have been used to propagate Syringa vulgaris 'Montaigne' (Montaigne lilac) and Chionanthus virginicus (white fringe tree). Growers need techniques that will make vegetative stem cuttings a more reliable propagation method. This would save growers money as they could reduce the time plants have to spend under mist. Larger quantities of salable plants could be produced more quickly. This research investigated the efficacy of using antitranspirants as a potential foliar treatment that would improve adventitious rooting and identify shoot characteristics that correlate with increased rooting percentages.

Rooting ability can vary a great deal among species and among cultivars within species. Some treatments that have been tried are severe pruning and light exclusion at budbreak. This study showed little benefit in treating cuttings with antitranspirants. They did find that lilac cuttings taken from slimmer, shorter shoots will be more successful cutting material than that from thicker, longer shoots. Shading stock plants may improve rootability. Much more research is needed in this area.

(from "Antitranspirant Treatments of Stock Plants Do Not Alter Growth and Adventitious Rooting of Shoots of 'Montaigne' Lilac and White Fringetree" by Susan M. Switras-Meyer and Jeffrey H. Gillman, published in J. Environ. Hort., December 2002).

THE WEED THAT ATE THE SOUTH HEADS NORTH

Washington State Department of Agriculture proposed adding kudzu to the state's Class A noxious weed list. Kudzu can grow 60 feet a year and has been called "the weed that ate the South." It was discovered in Washington's Clark, Grays Harbor and Island counties in the past 2 years. There have also been several small outbreaks discovered in Oregon since 2000. All of these infestations, as well as the ones in Washington, are believed to have been eliminated. Adding the plant to the Class A list would call for the immediate elimination of the plant once it was discovered in the state.

(from the Weekly NMPRO e-mail for Jan. 21, 2003, edited by Todd Davis).

NEW GROUP WILL KEEP VIRGINIA GREEN

A new, unified commercial horticulture organization was launched in Virginia. Virginia Green Industry Council's mission is, "to unify, strengthen and promote the green industry and maintain, promote and certify industry practices and principles that will keep Virginia green and growing." The VGIC developed a logo and a Web site, and hopes to represent all branches of the horticulture trade. Go to http://www.vahortcouncil.org

(from the Weekly NMPRO e-mail for Jan. 21, 2003, edited by Todd Davis).

REMEMBER LEWIS AND CLARK

Lawyer Nursery in Plains, Montana, is advising nurseries and garden centers to take advantage of the 200th anniversary of the Lewis and Clark expedition. The nursery recommends offering a collection of some of the 176 plants that Meriwether Lewis identified for science through the expedition. In 1803, Thomas Jefferson sent Lewis and William Clark west to discover an efficient route to the Pacific Ocean and to study new plant and animal life. Go to: http://www.lawyernursery.com

(from the Weekly NMPRO e-mail for Jan. 21, 2003, edited by Todd Davis).

GREENING ROOFTOPS

The Greening Rooftops for Sustainable Communities Conference is scheduled for May 29-30 in Chicago. This first-of-its-kind event is designed to unite growers, policymakers, researchers and green-roof-technology designers to discuss related issues. The conference will feature a trade show and a tour of Chicago-area green-roof projects. Some potential benefits of green roofs, or those planted with vegetation, are increased storm water retention, increased energy efficiency, reduced smog and lower summer air temperatures. Go to: http://www.greenroofs.ca

(from the Weekly NMPRO e-mail for Jan. 21, 2003, edited by Todd Davis).

PLANT PATHOLOGY REPORT

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

December was relatively quiet in the area of plant samples with 25 samples received. The lab was, however, very busy with soil nematode analysis samples.

Diseases seen in December included Pythium blight on bentgrass; Bipolaris leaf spot/blight on turf grass and small grains; Rhizoctonia brown patch on ryegrass and St. Augustine grass; take-all patch on St. Augustine grass; Phytophthora crown and root rot of fern.

December 2002 Plant Diseases Seen In The Plant Diagnostic Lab at Auburn
PLANTDISEASECOUNTY
BentgrassPythium BlightGA
Bermuda, CoastalBipolaris Leaf SpotPike
FernPhytophthora Root & Crown RotMobile
RyegrassBipolaris Lower Leaf BlightPike
RyegrassRhizoctonia Crown DecayPike
St. AugustineBrown Patch (Rhizoctonia)Dallas
St. AugustineTake-All Patch (Gaeumannomyces graminis
var.graminis)
Dallas
*Counties are not reported for samples from commercial greenhouse and nursery operations.

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

We're back into El Nino, which is cool and wet. For those interested in weather trivia like me, El Nino is a weather phenomenon characterized by an abnormally warm sea surface in the central equatorial Pacific Ocean. La Nina is when the sea surface is cold. Because of the El Nino pattern, rainfall was above normal (7.53 inches) and temperatures were below normal in Birmingham last month. This continues the weather trend seen during the fall. Fifteen samples were received during this typically slow month for the lab.

Stagnospora leaf spot, also called leaf scorch, causes red spots to form on flower stalks, leaves and petals of amaryllis. The spots can enlarge to several inches in length. On flower stalks, dark brown cankers with red borders can develop. Severely infected flower stalks may be stunted and fail to bloom. Control measures include preventing high humidity and overwatering, checking bulbs before planting for signs of disease, and discarding severely infected plants.

Alternaria leaf spot symptoms on dianthus include dark purple spots with sunken grayish brown centers. Sanitation and the use of fungicides (chlorothalonil or mancozeb) can be used to prevent additional disease.

December 2002 Plant Diseases Seen In The Birmingham Plant Diagnostic Lab
PLANTDISEASECOUNTY
AmaryllisStagnospora Leaf SpotJefferson
BentgrassDollar Spot *
BentgrassPythium Root Rot *
DianthusAlternaria Leaf SpotCullman
Southern MagnoliaAlgal Leaf SpotJefferson
Southern MagnoliaOleander ScaleJefferson
St. AugustinegrassBrown PatchJefferson
*Counties are not reported for samples from commercial greenhouse and nursery operations.


UPCOMING EVENTS

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.