660 CROP SCIENCE,VOL 41,MAY-JUNE 200 A.SREG2 B.SREGM.1 1.0 1.5 EA 10 EA 0.5 1520 0.0 214 CA WK 0.0 20. 月0.5 RN 20 19 RN D12 LN 121 ID LN 1.0 0.5 WE 0.0 0.5 1.0 1.5 2.0 Primary Effect(29.6%) .1.0 1.0 0.50.0 0.51.0 1.5 Primary effect(26.7%) 1996-1999Dat 5 and 12.The tterns are similar in the SREGy cates ke the 1996 dat sRECnpbtPCsorsodiieetse2aIg than that by PC2(24.5 vs.227%)As a result.the was o A.SREG2 1.5 15 1.0 1.0 12 0.5 94 G9 G13 125 0.0 G2G5 197 G2 3 10.5 66 6 0 1.0 .15 -15 .1.51.0 -05 0.0 0.5 1.0 1.5 2.0 -0.5 0.0 05 10 1.52.0 Primary effect (54.1%) Primary effect(40.8%) ace trial data.Each site is represented by anumber,and each 660 CROP SCIENCE, VOL. 41, MAY–JUNE 2001 Fig. 2. SREG2 and SREGM11 biplots for the 1996 Ontario winter wheat performance trial data. The numbers are different cultivars; the sites are CA 5 Centralia, EA 5 Elora, HN 5 Harriston, HW 5 Harrow, ID 5 Inwood, OA 5 Ottawa, RN 5 Ridgetown, WE 5 Woodslee, WK 5 Woodstock. main effects (r 5 0.83). The SREG2 biplot indicates that 1996–1999 Data cultivar G6 was the best for nearly all sites except Sites 4, 6, and 7, at which Cultivar G4 (and also G10) was Although the environmental PC1 scores in the SREG2 better than G6. Cultivar G7 was as good as G6 for Sites model tend to be of the same sign for yearly MET, 5 and 12. These patterns are similar in the SREG they often take different signs when multi-year data are M11 biplot (Fig. 3B). It indicates that Cultivar G6 was on jointly analyzed. For this dataset, among all 34 year-site average the best and Cultivar G12 the second best, and combinations, 9 had negative PC1 scores and the rest that Sites 5 and 12 were highly discriminating but neither had positive PC1 scores (Fig. 4A). Like the 1996 data, was representative. Interestingly, all sites had positive the GGE explained by PC1 was only slightly greater primary effects in the SREGM11 biplot, as compared than that by PC2 (24.5 vs. 22.7%). As a result, the with the site PC1 scores of different signs in the correlation between cultivar PC1 scores and cultivar SREG2 biplot. main effects was only 0.58. This low correlation prevents Fig. 3. SREG2 and SREGM11 biplots for the 1995 Ontario winter wheat performance trial data. Each site is represented by a number, and each cultivar is represented by a number preceded by the latter G