EARLY MEASURES OF BASAL AREA AND CANKER DISEASE PREDICT GROWTH-POTENTIAL OF SOME HYBRID POPLAR CLONES

Differences in percent survival, canker disease rating, and basal area (m(2)-. ha(-1)) were quantified for a plantation of 54 hybrid poplar clones in northern New York at ages 3 and 9 years to test the hypothes is that early growth and canker incidence indicate future growth. Diff erences in growth and canker severity between clones with similar pare ntage were assessed. Five of the seven clones, which exhibited high ba sal areas and low disease ratings at 3 years of age, maintained their growth potential at 9 years of age. Four of the five clones, which had 0% survival at 9 years of age, had low basal areas at 3 years of age. The growth potential of the remaining clones was not accurately predi cted based on early measures of growth and disease incidence. Variatio n in basal area and canker rating among clones within the same parenta ge group made it impossible to use parentage as a predictor of growth potential. Correlations among canker rating and basal area and percent survival increased over time, suggesting that impacts of canker disea se became more significant with age. Septoria musiva Peck was suspecte d to be the primary cause of stem cankers, but isolations revealed the presence of many fungi.