Organic chestnut farmer, Chris Foster of Cascadia Chestnuts in Portland, Oregon, shares some of his first-hand knowledge about the American chestnut tree, and its unique place in our history. As you see in the video, in Sherwood, Oregon, there exists what some believe to be the largest remaining American Chestnut tree in North America.
Before the turn of the 20th century, it was the predominant tree in the eastern half of the United States. The American chestnut was hit hard with the chestnut blight around 1904 from a fungus that originated in China. Since the American varieties of chestnut tree had never encountered this fungus before (Cryphonectria Parasitica), they died by the millions in droves. The blight was said to have spread as fast and as wide as 50 square miles per year.
Besides their majestic size and beauty as they reached maturity, the American chestnut tree is larger in size than their Asian and European counterparts. In the pre-blight era, the wood was used as flooring in barns, as plywood core, and other secondary uses where natural resistance to rot was a key prerequisite. In addition to their commercial value as wood, the chestnut was eaten by many people, and fed to livestock, and for tannins in making finished leather.
A recent New York Times post, Like-Minded Rivals Race to Bring Back the Chestnut Tree writes about two independent teams that are tackling the blight problem using very different approaches.
The American Chestnut Foundation, a nonprofit seeking to restore the chestnut tree, for decades has been using traditional breeding methods, to develop a hybrid with the high blight resistance of certain Asian varieties, while preserving the key attributes of the American chestnut varieties (their relative size, and general heartiness under local conditions), over successive generations (it is believed to take 6 generations, a generation is six years long, to produce a seed with the desired, stabile mix of traits ) with a final hybrid that’s about 92% American.
The other approach by the State University of New York College of Environmental Science and Forestry involves the use of biotechnology to transfer an enzyme producing gene from the wheat plant which can neutralize the toxic oxalic acid formed by the infecting fungus. This approach which uses only American chestnut varieties, relies upon the transferred gene to produce the necessary enzyme in sufficient quantity, and in a timely fashion to prevent the oxalic acid that is exuded by the fungus on the outside trunk area, to render the chemical harmless before it can cause damage to the tree.
It will be exciting to see in 20 or 30 years, to what extent, those beautiful American Chestnut trees abound.