Sharon, You make a good point, I really don't know, but what you say makes very good sense. On the site that sells Chestnut trees to the growers, they were talking about what the 'Growers' should do to maximize their crop yield is intersperse a one to ten ratio of a different hybrid. We don't need 'maximized crop yields', just enough for the furry tailed tree critters with some left over for us :) I will be starting the seeds in my green house with a heat mat under under the pots. I will post the progress on them. These are gorgeous looking nuts, far superior to those Chinese nuts you get in stores, Lou

Yes, I suspect all three approaches will be useful. Northern areas will work fine with the backcross method, as nature culls for the less hardy Chinese phenotypes. I tried the ACCF pure American ones, but we have had some worse than usual winters and they have all frozen back repeatedly. Many have died and the rest are about a foot high after 4 or 5 years. I don't see them ever getting vigourous enough to set seed....not at my latitude anyway. (46 degrees, 22 minutes). They might work well further south, I don't have a way to measure that. The wheat gene is not a problem for me, as I can eat wheat. It has not be approved yet, not released yet, so I don't know if I will ever get any...border crossings and all. Since I have been playing with spuds for more than a few years, I can say that multigene potato blight resistance does work. It probably will for chestnut too. I suspect we will hedge our bets, trying all three approaches, just to up the odds of some trees growing well in many areas. Southern areas will not have cold to weed out the Chinese early leafing traits, or lack of cold hardiness, so that will need active selection. They have added a biomarker for the wheat gene, so those transformations that actually do incorporate the gene and any resultant seedlings from those trees, will be recognizable at sprouting. I can't test for blight resistance here, on PEI, as PEI is blight free at the present time. Blight has not arrived yet. We have some some 200 year old trees within driving distance of my house, so I'm getting slips to graft as I can. It's fun. The local seedlings are very cold adapted, but slower growing...almost grow anywhere trees, but catkin hardiness at bloom is an issue for some years. Plus 3 or 4, degrees C and the anthers may not pop out.

Regular irrigation (water) during the growing season. ==>> depends on the media ... most trees like a sip of water.. and then near drying before the next watering ... do not water them like water hungry annuals and perennials ... insert your finger.. and learn how to tell.. when the media is drying ... in my experience.. small pots should not be in full sun ... the plants should.. but not the pot ... the sun can make the small media mass much more hot that roots prefer .. so figure out how to keep the pot in shade ... ken

Thought this might be of interest: https://www.nationalgeographic.com/environment/2019/06/saving-chestnut-trees-ozarks/?cmpid=org=ngp::mc=social::src=facebook::cmp=editorial::add=fb20190624env-lostozarktree::rid=&sf214771832=1&fbclid=IwAR0S5irMrRT7HxtssJI-O3Px6rOqbQZex7RKBm9dpWoYSOL1MFhXUt539c8