Canadian Forest Service Publications
Effects of cone scorching on germinability and vigour of lodgepole pine (Pinus contorta var. latifolia) seeds in Alberta. 1992. Wang, B.S.P.; Downie, B.; Wetzel, S.; Palamarek, D.; Hamilton, R. Seed Science and Technology 20: 409-419.
Available from: National Capital Region
Catalog ID: 10746
Serotinous cones of lodgepole pine (Pinus contorta var. latifolia Engelm.) from a large, relatively uniform, cone lot from a stand collection in Alberta weere subjected to six different methods of opening the cone scales: (1) drying at 60 C for 16 hours in a conventional kiln, (2) drying at 60 C for 23 hours in a rotating drum kiln, (3) scorching at 220 C for 0.5 minute, for 1.0 minute (4), for 1.5 minutes (5), and for 2.0 minutes (6). Cones from treatments 3-6 were also subjected to drying in the rotating drum kiln, as in treatment 2, immediately after scorching. Seeds with the best overall vigour, ascertained from germinatin tests following accelerated ageing treatment for periods of 0, 3, 7, 12, 17 and 21 days followed by prechilling, were those extracted in the drum kiln from cones receiving up to and including 1.5 minutes of scorching. The 2.0 minute scorching treatment was associated with a significant decrease in the germinability and vigour of seeds and indications of a loss of membrane integrity. Seeds from the rotating drum kiln were superior in vigour when compared to those from the conventional kiln. This may be due to the fact that seeds released from cones during the drying cycle are able to drop free of the kiln environment in the drum kiln. In the conventional kiln seeds which fall from the cones are retained in the kiln for the full 16 hours drying treatment, possibly harming the seeds by prolonged exposure to the kiln environment.