1. Horticultural Research Centre, Dép. des Sols et de Génie Agroalimentaire; Univ. Laval, Envirotron; 2480 Hochelaga Québec QC Canada G1V 0A6
2. Dep. of Plant Science; McGill Univ.; Macdonald Campus, 21111 Lakeshore Rd. Ste-Anne-de-Bellevue QC Canada H9X 3V9
3. Pedology and Agricultural Precision Lab.; Agriculture and Agri-Food Canada; 979 Ave de Bourgogne Québec QC Canada G1W 2L4