By Hill Craddock, TN Chapter President
The Tennessee Chapter held a very successful one-day pollination workshop on Saturday, June 10, 2023, at the beautiful Chestnut Ridge Orchard in Middle Tennessee.
The pollination workshop was led by TN Chapter President, Hill Craddock (left).
The workshop was a hands-on opportunity to learn and practice techniques to make controlled crosses for TACF’s breeding program. More than a dozen people from Mississippi, North Carolina, and Tennessee came together for a day of chestnut breeding. All steps were covered in the process: finding and identifying American chestnut trees, the basic biology of the genus Castanea, how to recognize the male and female flowers, emasculation and bagging, pollen collection and handling, labelling and record-keeping, and all the intimate details of hand pollination. More than 100 hand pollinations were made on two trees at the site. The pistillate parents (moms) (TN-RC09-1-24 and TN-RC09-3-62) were chosen based on evidence of their resistance to chestnut blight. The pollen parents (dads) (TN-TTU05-A30 and TN-TTU05-A34) were chosen based on their known ability to pass resistance to phytophthora root rot disease (PRR) to their offspring. Our hope is that the results of this workshop will produce hybrid trees that combine resistance to blight and PRR.
A volunteer practices bagging techniques.
Participants listen carefully to Hill Craddock’s demonstration.
The Chestnut Ridge Orchard (also known as the Ruth Cochran Orchard) was planted in 2009 by TN Chapter volunteers using the direct seed method. Additional plantings at the site were made using transplants in 2010. It originally included almost 500 trees of TACF backcross hybrids in the F1, B1, B2, B3, and B4 generations, all resulting from hand pollinations, Castanea dentata and C. mollissima (the experimental controls), and C. pumila, C. ozarkensis, C. alabamensis (the Chinquapins). In 2017 the hybrids were screened for blight resistance using Cryphonectria parasitica strains EP155 and SG2-3. The orchard was rogued in 2018, 2019, and 2022.
The successful day of training ended with a group photo of proud participants.