1 Identifying Isoyield Environments for Field Pea Production 2 3 4 5 Rong-Cai Yang*, Stanford F. Blade, Jose Crossa, Daniel Stanton, and Manjula S. Bandara 6 7 8 9 Rong-Cai Yang and Daniel Stanton, Policy Secretariat, Alberta Agriculture, Food and Rural 10 Development, Room 300, 7000 – 113 Street, Edmonton, AB, Canada T6H 5T6 and Dep. of 11 Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 12 2P5; Stanford F. Blade, Crop Diversification Centre North, Alberta Agriculture, Food and Rural 13 Development, RR6, 17507 Fort Road, Edmonton, AB, Canada T5B 4K3; Jose Crossa, 14 Biometrics and Statistics Unit, International Maize and Wheat Improvement Center (CIMMYT), 15 Apdo. Postal 6-641, 06600 Mexico D.F., México; Manjula S. Bandara, Crop Diversification 16 Centre South, S.S. #4, Alberta Agriculture, Food and Rural Development, Brooks, AB, Canada 17 T1R 1E6. Received _______________. *Corresponding author (
[email protected]) 18 19 Abbreviations: AFPRVT, Alberta Field Pea Regional Variety Test; CV, coefficient of variation; 20 GEI, genotype-environment interaction; UPGMA, unweighted pair-group method using 21 arithmetic averages. 22 1 1 ABSTRACT 2 Cultivars are often recommended to producers based on their averaged yields across sites 3 within a geographic region. However, this geography-based approach gives little regard to the 4 fact that not all sites in a given region have the same level of production capacity. The objective 5 of this paper was to describe a performance-based approach to identifying groups of sites with 6 similar yielding ability (i.e., ‘isoyield’ groups), but not necessarily contiguous, and its use for 7 analyzing the yield data from field pea (Pisum sativum L.) cultivar trials conducted across the 8 Province of Alberta, Canada from 1997 to 2001.