Blighting the Chestnut Trees

Adding blight to healthy American chestnut trees, through inoculation, seems counter-productive and makes little or no sense!  However, that is what was done with a 5 - 6 year old chestnut orchard not far from Louisville on the morning of June 22, 2013.  Nearly 165 trees were infected with chestnut blight, which included potentially blight resistant American trees, Chinese trees, pure American trees (no resistance) and half American/half Chinese trees.  This variety of trees provides for a "control" to measure against when determining blight resistance.

Healthy 15/16th American chestnut trees soon to be blighted.  (Photo by Ed Fredrickson.)

So, why would anyone want to intentionally blight these apparently healthy and nut producing trees?  As questionable as this sounds, the answer truly is, "to save the trees!"

TACF Southeastern Regional Science Coordinator, Tom Saielli, inoculates the first tree in the orchard. (Photo by Ed Fredrickson.)

Huh?  Please clarify!  Okay, here is the deal (short version).  These trees have been back-cross bred for blight resistance.  Not all of these trees will demonstrate high resistance, so they need to be "tested" to find out which ones carry the most resistance within their genetics.  Those that do will carry forward with breeding to eventually provide offspring that will be placed back into our Kentucky woods to naturally reproduce, compete, and fulfill the former niche provided by American chestnut trees!

There are two genetic lines represented in this orchard, with about 70 trees of each.  They have all been given two doses of different strains of chestnut blight.  The inoculation points (holes punched through the bark, blight added, taped over to "seal" it in) will produce "sores" on the trees.  Some will show resistance to these infections by attempting to heal over the "sores."  Others will completely fail, so will die.  Measurements will determine which trees show good resistance and which ones should be "culled from the herd."  Yes, those that fail will not be allowed to continue in the breeding process.

Ultimately, it is hoped that 5 or 6 trees from each genetic line will "pass" the resistance evaluation and will be allowed to naturally breed across the two lines.  Then, the nuts produced from these trees will be used through a similar process with another unrelated genetic line that "passed" a similar test.  The offspring of this next generation (in 5 or 6+ years) will be considered "Restoration Chestnut 1.0" trees, so will be ready for out-testing in forested conditions to see how they compete, how they resist natural blight and other vectors and may well be some of the future "redwoods of the East" that we read about in books, diaries and other documentation of how American chestnut trees used to be throughout our Eastern US woods.

Interested in helping with the American chestnut program in the Louisville area?  It isn't all work, as some of it is a lot of fun!  You could help follow up on a report of a chestnut tree out in the woods, such as in Jefferson Memorial Forest, at Otter Creek or on someone's private land.  Maybe you would rather help write a news release of ongoing activities within the Louisville area?  Maybe you can only occasionally participate, so would like to water growing trees within the Louisville area every couple of weeks as a "chestnut steward?"  Well, come on, get involved to help revive this tree!  Comment on this blog or send an email to Keith at kchacha@yahoo.com and we'll get you involved!  All assistance is appreciated and accepted!  Even if you can only assist monetarily, that is greatly needed, as well!

A "chestnut steward" is providing care for the four tree grove of chestnut trees located out front of the Louisville Nature Center.  The rain hasn't stopped since watering devices were installed (after photo was taken).  (Photo by this blogger.)

Learn more about efforts to restore the American chestnut tree at www.acf.org.

Be sure to check all postings at http://louisvillechestnut.blogspot.com/ for the Louisville Chestnut Trees blog!