Archive for the ‘Plant Pathology’ category

Check Native Impatiens/Touch-me-not/jewelweed for Downy Mildew

June 7, 2012

Recently there have been outbreaks in the Northeast of a potentially devastating disease on garden impatiens (Impatiens walleriana), a downy mildew caused by Plasmopara obducens.  Cornell Cooperative Extension is looking for help in determining whether this downy mildew is currently affecting native jewelweeds. The New Guinea impatiens (I. hawkeri) does not seem to be affected.  For more info on the disease CLICK HERE.  For more information on what to look for CLICK HERE. If you find what you think is the mildew, collect a sample of the leaves in a clean plastic bag with a moist paper towel, seal it, and mail to:

Margaret Daughtry, Cornell University-LIHREC, 3059 Sound Ave., Riverhead, NY 11901.

This shows what happens to garden impatiens with the mildew.


SUNY ESF Alumni Sponsor the Return of the American Chestnut

February 18, 2012

On April 18, test trees of American chestnut produced by the Restoration Project at ESF will be planted at an event at the New York Botanical Garden, the place where chestnut blight was first discovered in 1904. The Research Project has more than 100 varieties either in field trials or waiting to be tested.  The event will include a lecture on chestnut trees at 3 p.m. followed by a planting of trees at 4:30 and a reception and dinner at 6:00 in the renovated  stone mill at the garden. Fees are $31 for the lecture and $100 for the dinner. Reservations are required and sponsorships are encouraged.  If you are interested contact the ESF alumni office at 315-470-6632 or Let’s hope this is the beginning of the return of the American chestnut tree to our eastern forests.

News About the Status of Butternut From Perdue University

August 8, 2011

From Keith Woeste, U.S. Forest Service Hardwood Tree Improvement and Regeneration Center (HTIRC)

Dear Friends of butternut;

This letter and THIS CLICKABLE PDF FILE are about butternut (Juglans cinerea).  We are providing them to keep you informed about what is happening with butternut and butternut-related research, especially at Hardwood Tree Improvement and Regeneration Center (HTIRC).  HTIRC is research collaboration between the USDA Forest Service (Northern Research Station) and Purdue University (

The PDF file contains a description of the mission of HTIRC with respect to butternut, some photos, descriptions of ongoing butternut research, and links to some butternut-related websites.

Many hundreds of foresters, biologists, naturalists and landowners have contacted HTIRC over the past 10 years about butternut.  I cannot thank you enough for your pictures and samples and other contributions to our work.  I have only ‘met’ most of you by email after you contacted HTIRC.   In some cases, your interest and willingness to help were so great that our staff and resources were overwhelmed by the volume of samples and requests.  As a consequence, at times I didn’t reply to some inquiries in a timely manner or with all the data you requested.  I am sorry for that, and I wish I had more time and resources to offer.  Butternut canker is only one of many threats to the sustainability of the eastern hardwood forest, a resource we all value.  At a time when funds are scarce, the best way forward is to communicate and cooperate.  We do want to hear from you if you have thoughts about research priorities or research opportunities, or if you have resources that may help.

There is no “Butternut Society” or other organized group especially for butternut recovery—at least none that I am aware of.  So for now, we will do our best to keep you informed with periodic letters and updates to our website.  There is much to do if we are to succeed in keeping butternut a vital part of the eastern hardwood forest.  We improve our chances if we all pull together. We expect that updates about butternut will be provided on an occasional basis—certainly no more frequently than twice each year.

Write to me at if you have any questions or need additional information.  My complete contact information is below. Please share this information with anyone who you think will be interested in it.

Yours sincerely,

Keith Woeste

U.S. Forest Service Hardwood Tree Improvement and Regeneration Center (HTIRC)

Department of Forestry and Natural Resources, Pfendler Hall, Purdue University

715 West State Street, West Lafayette IN 47907-2061


phone: 765-496-6808

A Disease of Dirca palustris, Leatherwood

September 4, 2009
Dirca leaves
Dirca leaves

From Steve Young: My son Alex took this photo of leatherwood in Saratoga County today while on a trip with Jackie Donnelly.  She has noticed this disease affecting Dirca for some years and it makes the plant stand out in the woods this time of year.  Anyone have any suggestions as to what it is?

Update Sept. 09: Leucanthiza dircella (Lepidoptera: Gracillariidae): A leafminer of leatherwood, Dirca palustris. It seems that this leaf miner and a rust make the leaves of Dirca turn yellow in August.