Friday, November 21, 2008

American chestnut

Needed: a photograph of an American chestnut to be enlarged to a height of two stories for a museum exhibit about chestnut trees and the Appalachian mountains. Where do you suppose the paragon of chestnuthood worthy of such photographic extravagance was found? Why, suburban New Jersey, of course. The photogenic chestnut is shown below with its discoverer, Tony Rosati, and his border collie, Jessie. The tree is 19" in diameter at chest height and is next to a path through the woods behind the Middletown Public Library. Mr. Rosati discovered the tree a few years ago while he was strolling in the woods with Jessie, just killing time while waiting for a canine agility training course.

The black discolorations on the tree's bark are the result of chestnut blight. More detail of chestnut blight injury can be seen in the photographs in Note 4.

Tony Rosati was in Plainfield a few weeks ago to visit our own American chestnut, a 10" diameter tree at 946 Madison Avenue. The tree was planted in 1992 by Bill Santoriello and is now owned by Vicki Blasucci. Robin Gates wrote to report on the existence of this tree as a correction to my September 2007 blog posting on chestnuts ( ). My posting had made the (seemingly safe, but erroneous) assertion that one probably had to leave Plainfield to see an American chestnut.

The Madison Avenue chestnut has become a star. Someone posted forty photographs of the tree on Flickr . Members of the Pennsylvania chapter of the American Chestnut Foundation are interested in the tree because it has reached a considerable size(1) in good health and with a graceful shape. Past president of the chapter Bob Summersgill recently visited the Madison Avenue chestnut. He concluded from a quick inspection that there were no other chestnuts in the vicinity. How did he know that? He had two important clues. First, the tree had no injury from chestnut blight, which it almost surely would have had if there had been a nearby chestnut to transmit the infection. Second, the tree was producing only sterile burs, lacking a nearby chestnut to serve as a pollinator. Mr. Summersgill showed me the papery "non-nuts" inside the unfertilized burs (pictured below).

Unfertilized chestnut bur with papery, brown "non-nuts" in the center. Even the squirrels have no use for them.

Rosati and Summersgill have great hopes for the Madison Avenue chestnut. They would like to provide pollen for the tree so that it can reproduce. The flowers could be hand-pollinated with pollen from another chestnut. Alternatively, blight-free chestnut seedlings could be planted nearby, and the wind could do the work of pollination.

Rosati and Summersgill's work was featured in the October 9 edition of the Star-Ledger.(2) The article focused on American chestnuts in the Monmouth County parks, some of the best surviving examples of the species in the eastern United States. Volunteer workers hand-pollinate the chestnut flowers in the spring, bag the flowers to keep out other pollen, and harvest the resultant bagged chestnuts in the fall. This is not work for the faint of heart. Chestnuts only produce flowers on branches that are exposed to the sun. For a tree in the woods, that means the top branches only. The volunteers go up as high as 75 feet in a cherry-picker to accomplish their mission.

But this is New Jersey; there must be another twist to this story. What do the chestnut harvesters do with the chestnuts that they collect? They plant some of them in the garden of Vito Genovese, (now Deep Cut Gardens, part of the Monmouth County parks system, the garden was created by Vito Genovese). Yes, that Vito Genovese. Reputed to be the convener of the ill-fated 1957 mob conference in Apalachin New York, Vito Genovese is also said to be the man who ordered the barbershop assassination of Murder, Incorporated's Albert Anastasia.(3) When Mr. Rosati took me to visit the little chestnut nursery at beautiful and peaceful Deep Cut Gardens, I could sense the spirit of Vito Genovese watching over the tender saplings and frightening off predatory deer.(4)

(1) A considerable size by the standards of today. American chestnuts used to mature at trunk diameters many times the size of the Madison Avenue tree's.

The Monmouth County chestnut work cited in the article is a collaborative effort involving the Monmouth County Park System, The Monmouth County Shade Tree Commission, the Middletown Parks and Recreation Department, and the Pennsylvania chapter of the American Chestnut Foundation.


(4) American chestnuts are sometimes able to survive chestnut blight until they're old enough to produce nuts. In addition, the stumps of fallen chestnuts send up new shoots that mature to bear nuts. All other things being equal, the species might presumably limp along that way until it develops resistance to chestnut blight through genetic mutation. The explosion of the deer population has placed another obstacle in the way of hopes that the species will escape extinction, however. Deer are very willing to eat chestnut shoots.

While I can't claim to keep up with the research, I know of several avenues along which workers hope to develop blight-resistant American chestnuts. 1. Breeding the Chinese chestnut's resistance into American chestnuts. The American Chestnut Foundation has a program that crosses Chinese chestnuts with Americans to confer resistance and then "backcrosses" the progeny with Americans over several generations to dilute out the Chinese characteristics while maintaining the blight resistance. 2. Other researchers are using molecular techniques to decipher and/or modify chestnut DNA. 3. Hypovirulence: weakening of the chestnut blight fungus with an antifungal virus. 4. Natural resistance. It's not clear why Monmouth County's parks have American chestnuts that survive better than American chestnuts elsewhere. Perhaps they have evolved some measure of blight resistance. It's just possible that Tony Rosati and coworkers will produce a highly blight-resistant strain in their little chestnut nursery in Deep Cut Gardens. If they do, I will lobby hard to persuade them to name it Castanea dentata 'Vito Genovese'.

The blackened areas on the trunk pictured above are the sequelae of chestnut blight.

Damage from chestnut blight at the tree base.

Damage from chestnut blight

Copyright Gregory Palermo