1. Dep. of Soil ScienceUniv. of ManitobaWinnipegMBCanadaR3T 2N2
2. Ottawa Research and Development CentreAgriculture and Agri‐Food CanadaBuilding 99, Central Experimental FarmOttawaONCanadaK1A 0C6
3. Dep. of Plant ScienceUniv. of ManitobaWinnipegMBCanadaR3T 2K1