1. Crop Production; Eastern Cereal and Oilseed Research Centre; Agriculture and Agri-Food Canada; 960 Carling Ave. Ottawa Canada K1A 0C6
2. Land and Water Commonwealth Scientific and Industrial Research Organization; G.P.O. Box 1666 Canberra ACT 2601 Australia
3. Water Research Foundation of Australia, Centre for Resources and Environmental Studies; Australian National Univ.; Canberra ACT 2601 Australia