Genetic correlations between growth and growth rhythm observed in a short-term test and performance in long-term field trials of Norway spruce

Genetic parameters were estimated for traits observed in one short-term "farm-field" test and in seven long-term field trials of Norway spruce (Picea abies (L.) Karst.). The trials, located in southern and central Sweden, were based on subsets of 201 openpollinated families derived from plus trees grafted in seed orchards. Observations of height growth and phenology in the farm-field test were made during years 2-4, and trees in field trials were assessed for height and damage at 9-14 years of age. Narrrowsense heritabilities for height-growth traits in the field trials varied from 0.05 to 0.47. Heritabilities in the farm-field test were approximately 0.80 for date of bud burst, 0.35 for leader lignification, and 0.20 for frequency of seedlings with free growth. Early bud burst and a high degree of free growth in the farm-field test were genetically correlated with lower height and higher frequency of ramicorns and frost damage in the field trials. Height in the farm-field test was poorly and inconsistently correlated with height in the field. Genetic correlations for final heights among the field trials were usually significant and in the range of 0.7 and above. Correlations did not decline with distance between trials, suggesting that local climate is more important than regional climatic zones when matching site and genotype.