Intermediate Physiological Dormancy Excised embryos will growExcised embryos will grow As much as 6 months prechilling neededAs much as 6 months prechilling needed Gibberellins, kinetin, thiourea can shorten prechilling requirementGibberellins, kinetin, thiourea can shorten prechilling requirement Acer negundo, Acer pseudoplatanus, Acer saccharum, Corylus avellana, Fraxinus americana, Fraxinus pennsylvanicaAcer negundo, Acer pseudoplatanus, Acer saccharum, Corylus avellana, Fraxinus americana, Fraxinus pennsylvanica Fagus sylvatica – ethylene accelerated and increased germination at 15°C, at 5°C chemicals no better than water soak on germination, GA 3 increased germination of unchilled seeds at 15°C, 10 weeks prechill negate chemical effect (Seed Sci 2004, p21-33)Fagus sylvatica – ethylene accelerated and increased germination at 15°C, at 5°C chemicals no better than water soak on germination, GA 3 increased germination of unchilled seeds at 15°C, 10 weeks prechill negate chemical effect (Seed Sci 2004, p21-33)