2014 Progress Report -Cold Hardiness Testing of Apple Rootstock Genotypes in Maine

摘要

Three experiments were conducted in the last year to test cold hardiness in apple rootstocks.Experiment 1. We measured the relative level of hardiness in 10 Geneva selections, three Vineland selections, as well as in M.7, M.9 G.30, G.41 and G.935 in January, April and October 2014. This was the second and third year of the three-year study. In fall 2014, rootstocks were tested twice to measure the change after exposure to freezing temperature. Since very little difference in hardiness occurs in Jan-uary, midwinter measurements will not be repeated in 2015. Instead, additional measurement will be done in spring as trees lose hardiness. Bud.9 was added to the collection in fall 2014.