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Florticulture AoE Team

No. 9, April 25, 2007

In this issue
White mold (Sclerotinia sp.)
The 2007 Michigan Garden Plant Tour
Application technology for small acreage producers

White mold (Sclerotinia sp.)
Jan Byrne
MSU Diagnostic Services

Recently in the diagnostic lab we have seen several cases of disease caused by white mold. Infected plants included lobelia (stem rot) and gazania (blighting) and gerbera (crown rot). Sclerotinia has a wide host range including many annuals, perennials, vegetables and field crops. Disease symptoms include pre and post-emergent damping off, crown rot, and blighting of foliage and petioles. Small, hard, irregular, black structures called sclerotia may be present on or in plant tissue (especially inside stem and petiole tissue). White fluffy growth is produced on affected plant parts – this is most readily visible in high humidity.

Disease is spread mainly via sclerotia. These are long term survival structures, that are found in soil and on plant debris. Movement of these structures is the primary means of disease spread. Disease can also be spread by the movement of infected plant material. Under certain environmental conditions, mushroom like structures (apothecia) are produced and they release airborne spores.

Disease management is primarily based on avoidance of the pathogen. Field soil should be sterilized before using it in growing media. Susceptible crops should not be grown in areas with a history of white mold problems. Additionally, good sanitation is important to limit spread. Weeds should be controlled in production areas, because some weeds are hosts to Sclerotinia. Fungicide drenches can be used to protect plants from infection. Fungicides labeled for control of Sclerotinia in the greenhouse include chlorothalonil, thiophanate-methyl and PCNB.

The 2007 Michigan Garden Plant Tour
Erik Runkle
Horticulture

Six leading young plant growers in Michigan are teaming up with Michigan State University (MSU) to offer garden plant displays and tours from July 30 through August 10. Greenhouse growers, retailers and landscapers are invited to visit the participating companies to learn about new garden plant varieties and observe how they perform in beds, landscapes and containers. The 2007 Michigan Garden Plant Tour sites are:

C. Raker and Sons
Duwayne’s Greenhouse Inc.
Four Star Greenhouse Inc.
Glass Corner Greenhouses Inc.
MSU Horticulture Gardens
Pell Greenhouses, Inc., and
Walters Gardens, Inc.

Each location showcases different plant specialties and product lines. Companies are open Monday through Friday during normal business hours and the MSU Horticulture Gardens are open daily from dusk to dawn. We suggest that you contact the sites in advance so that they know you are coming. There is no fee to attend the tour, and the educational program at MSU on August 7 is only $35 per person and includes interesting and informative presentations, lunch, parking, and a trial booklet.

Visit the Michigan Garden Plant Tour website at www.hrt.msu.edu/planttour or call Sandy Allen at 517-355-5191 ext. 1339 for more information. Last year, nearly 2,000 people attended the Michigan Garden Plant Tour and 64 percent spent at least two days visiting the participating plant producers. An amazing 92 percent of the last year’s attendees indicated that they would attend the tour this year!

Application technology for small acreage producers
Roberta Dow
Northern District Water Quality Educator
Michigan Groundwater Stewardship Program
Michigan State University Extension

This workshop is designed for pesticide applicators working with nurseries, greenhouses, vegetables, floral, forest and other small acreage settings.

June 14 from 6:00 – 9:00 PM
Northwest Horticultural Research Station
6686 Center Rd.
Traverse City, MI

Dr. John Grande, Snyder Research Farm, Rutgers University will be the featured speaker. Different types of liquid applicators (pump and powered backpack sprayers, backpack mist blowers, small – <150 gallon – sprayers mounted on Mule, etc.) will be demonstrated, discussed and calibrated. Modifications for different usage will be presented. Spray efficacy will be demonstrated.Attendees will gain hands-on experience.

Two core recertification credits for commercial and private applicators have been applied for. The cost is $5. The rest of the program expense is sponsored by a North Region Project GREEEN grant.

To register, send check for $5 to:
Roberta Dow, MSU Extension Grand Traverse County
520 W. Front St.
Traverse City, Michigan 49684-2208.

For more information, contact Roberta Dow, dowr@msu.edu

The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the Michigan Agricultural Experiment Station, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.
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