Jack pine establishment in Ontario: 5-year comparison of stock types ± bracke scarification, mounding, and chemical site preparation

Field experimentation was begun in 1984 to assess performance of jack pine (Pinus banksiana Lamb.) (2 + 0 bareroot and FH408 Japanese paperpot) in relation to mechanical site preparation, including Bracke scarification with and without supplementary mounding, and site preparation using Roundup® herbicide. Twenty treatments encompassed 4480 trees in 40-tree plots split equally between bareroot and paperpot stock. The study site, about 200 km north of Sault Ste. Marie, Ontario, had deep silt loam soil. After 3 growing seasons, survival was significantly higher among bareroot than among paperpot stock, but survival no longer differed significantly (P < 0.05) between stock types 2 years later. In years 4 and 5, the rate of increase in mean total height of bareroot stock was 11% less than that of paperpot stock, though bareroot stock was 40 and 4.7 cm greater in mean total 5th-year height and 5th-year height increment, respectively. Paperpot stock needed mechanical site preparation more than did bareroot stock...