VA- Inoculations at Sky Meadows, day 2

June is a busy month for chestnut breeding. Tree inoculation will be done in the first half of June and pollination the second half. We use open pollinations to produce seed for our northern Virginia seed orchards, and have mostly finished harvesting seed for them. Now the trees have grown up large enough, it is time to test them for blight resistance. The first phase of selection entails inoculating them with the blight (giving them blight) and picking the winners.

When seed orchard trees are about 2” in diameter and 10-15 feet tall they are ready to be inoculated. We do this by boring a hole in the bark, removing a plug of bark and replacing it with a disk of agar and mycelium, the chestnut blight fungus. The agar and mycelium are cut from a culture of the fungus in a Petri plate. I am currently in the process of generating large numbers of culture plates for our activity.

In trees inoculated in 2022 and 2023 we have seen clear and statistically significant separation of family means, which is an indication that we have variability in blight resistance between families. Variation is good; we can pick the winning families and discard the losers. If there were no variation, we couldn’t select the best families. There also is variation between families that share the same grandparent but not the same parents. Again this is good because we can select the best. Finally, we can select the best trees within families as trees vary within families.

Our experience has been that a crew of three people can inoculate two plots of 180 planted nuts per day, from 9am to 3 pm. In 2023 we inoculated 11 plots, and 25 in 2023. For 2024, we have nine plots at Blandy, five at Banshee Reeks and four or more at Sky Meadows. With two crews, I estimate it will take two days to inoculate Blandy, and one each Banshee and Sky Meadows. We may inoculate a few more plots at Sky Meadows as they are coming along fast and we are in danger of getting swamped next year.

Successive weekends worked well this spring for planting, so I hope we can repeat this progress this June. The plan is to inoculate Saturday and Sunday over the weekends of June 8th — Blandy, June 15th — Sky Meadows, and June 22nd — Banshee Reeks. Please email back with your date preference and indicate whether you can work multiple days. It would be preferable to work both days of a weekend so we have continuity.

I look forward to getting out in the orchards with you and we will send out a confirming memo in the week prior to each weekend.

Yours Truly,
Fred

Frederick V. Hebard, PhD
Vice President, Virginia Chapter
The American Chestnut Foundation
mbiew@comcast.net
276 356-8517