Progeny freeze testing, progeny field testing and parental phenology of Pinus sylvestris (L.) clones in northern Sweden

Publisher Website
Google Scholar
Abstract
Artificial autumn freeze testing was used as indication on the level of cold acclimation of one year old fullsib and open‐pollinated plus‐tree progenies from three north Swedish seed orchards of Scots pine. Correlations between progeny freezing damage after initial cold acclimation in various environments were generally as high or higher than correlations between survival/condition in various ten‐year field trials. Slight freezing damage was related to good field survival and tree condition at ten years of age. A large variation in the rate of cold acclimation within geographical regions indicates that the geographical origin alone is not a reliable selection criterion in breeding for hardiness. It is suggested that a combination of artificial freeze testing in the autumn of one‐year progenies and of detached shoots from the parent clones should be used in selection and breeding for better survival in Scots pine on northern latitudes.