Abstract
Click on author name to view affiliation information
Contributor Notes
Received for publication 15 Feb. 1985. The authors thank René Pouliot and Jacques Debroux for their technical assistance, the service of audiovisual for making the figures, and Lucette Belanger for typing the manuscript. The authors also acknowledge the Québec Agr. Res. Council and Agr. Canada for their financial support. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.
Abstract
