By Dr. David Bingham
A group of Connecticut Chapter volunteers descended on the Salem orchard on April 14th, and planted about 200 nuts before dark on a beautiful day. Fifty of the nuts were from a native American Salem tree. These nuts were harvested last fall and lovingly cared for over the winter by Leila Pinchot, and have already shown high germination rates.
Care of the orchard has been greatly enhanced by a master cultivator, 89-year-old Harry O'Donnell. He read about the project, which stirred memories of his youth in Maryland amid dying giant chestnut trees. His father had a nursery business on the side, which included raising some chestnuts. Harry's help with cultivating around each sapling this summer, many hours of difficult manual labor to prevent the need for herbicides, has been an inspiration.
The Salem mother tree has flowered again. It is being re-pollinated, using the pollen from the same hybrid (backcross 3) father tree used last year, with the hope of completing the goal of about 120 nuts of backcross 4 genetic tree lineage. The severely blighted Salem tree has been treated in the meantime with hypovirulent fungus placed at sites of infection hoping to prolong its well-deserved survival. The fungus treatment comes with thanks for the laboratory work of Leila Pinchot at the CT Agricultural Experiment Station, under the tutelage of Dr. Sandy Anagnostakis.
A tree on the grounds of the Old Lyme Library has also been pollinated with BC-3 pollen. It was planted as a sapling by one of the founders of the CT Chapter, Dr. Phil Gordon, many years ago. It came from an island in an estuary on the lower Connecticut River which had a grove with several native American chestnuts on it. Hypovirulent fungus treatment of that tree was done by Dr. Anagnostakis several years ago, which undoubtedly contributed to its survival.
The bagging and pollinating process in Old Lyme, easily visible on Library Lane, resulted in many inquiries from passersby, allowing for some education (and perhaps some memberships!). Being on a Library site, where information can easily be disseminated (we gave a lecture here in March that got good newspaper coverage), this project should help widen our circle of supporters. It is also within a block of the Old Lyme High School.
Each BC-4 nut from these two trees will be about 97% American, 3% Chinese chestnut in DNA content, but all trees resulting from these nuts will be susceptible to blight, with varying degrees of partial resistance. When the most susceptible trees from these nuts are culled, the remaining trees will be allowed to cross-fertilize each other in the orchard with other partially-resistant hybrid strains of trees harvested from CT-native American chestnut mother trees.
Among the nuts from this future crop will be some nuts that are 100% resistant to the blight. It is the resistant trees from these nuts (trees that that will be identified about 10 years from now, when the blight-sensitive trees in this generation are culled out), that will provide the (F2) nuts for a reforestation program with “All-American” (i.e., 3% Chinese) chestnut trees. The expectation is that these trees, emerging as saplings about 12 years from today, will have the form and characteristics of the mighty chestnut of our original native Connecticut forest, but will be fully blight-resistant.