There are several types of American chestnut tree plantings with which we’ve been involved across the State of CT.
Back-cross Breeding Orchards
The back-cross breeding method for chestnut was developed in 1983 and has several key components, each of which requires research orchards for growing trees to be used in selections. The Connecticut Chapter of TACF manages seven back-cross orchards with approximately 3000 BC3F1 Clapper line of resistance, American chestnut backcross material. Each of these was planted from nuts that originated from CT found American chestnut “Mother Trees”
The next major phase of the breeding program and we are actively pursuing locations that could support the seed orchards. A seed orchard is the required next step in producing trees for reforestation in CT that have 50% of their DNA from persisting native CT American Chestnut trees that flowered, allowing pollination and collection of nuts. This DNA reflects the native gene pool that is associated with CT’s soils, light periodicity, disease resistance, rainfall patterns, temperature extremes, etc. These factors differ throughout the native chestnut range in the US and even within CT itself. Capturing this diversity is the goal of the CT program, and seed orchards are our organizational focus, and the primary use of our volunteer efforts.
Other research Orchards
There is a BC2F2 research orchard managed by TACF and located at White Memorial in Litchfield CT. This was an earlier type of back-cross orchard which remains of interest for morphological and resistance studies.
There are numerous locations throughout the state where progeny tests are being performed. These are nuts grown at the Meadowview seed orchards (intercrossed trees) as a result of open pollination. This means the mother tree is known and is selected for maximum resistance, and while the father tree is not known, all have likely been selected for resistance. Of course with open pollinations one can never be sure. This is a type of planting with which an individual or organization can participate in either a small or large scale … both contributing to our understanding of the blight resistance of the latest versions of releasable material. This is a great way for citizen scientists to participate in an ecological restoration project. Some of the sites in CT with restoration plantings include the Zemko Sawmill Site owned by the Salem Land Trust, and the Greenwich Land Trust American Chestnut Sanctuary.
The various chestnuts; Chinese, Japanese, European, American, even Chinquapin, have different morphology, and what better way to show that then an educational planting. We have several educational plantings around the state designed to illustrate the differing morphology, and teach those viewing the display about the chestnut blight story.
View CT Chapter TACF Orchard Locations in a larger map