FREE FATTY-ACID LEVELS IN ONTARIO-GROWN SUMMER RAPE CULTIVARS

High levels of FFA have been a recurring problem in the seed oil of On tario-grown, canola-quality summer rape (Brassica napus L.). Examinati on of seed samples from the Eastern Canadian Co-operative Cultivar Tri als conducted at several locations in 1988-1993 showed significant, co nsistent differences in FFA levels among cultivars. In each year from 1988 to 1991 the cultivars Kristina, Delta and Westar had FFA levels t hat were about 40% of those of Global and the triazine-tolerant cultiv ars Stallion, OAC Triton and OAC Triumph. Pearson's correlations and S pearman's rank correlation between years for FFA levels of genotypes w ere all significant, with the exception of the Spearman's rank correla tion between 1992 and 1993. Significant differences in FFA occurred am ong locations in southern Ontario, but location differences were not c onsistent across years. Cultivars grown in western Canada, however, ha d FFA levels between 2 and 41% of their FFA levels at the southern Ont ario locations. The FFA levels of cultivars at one Ontario location we re significantly correlated with the mean FFA levels of the same culti vars from all the other Ontario locations in the same year, 28 out of 34 times. Correlations were higher before the high-FFA cultivars were removed from the trials in 1991. Screening of lines in a breeding prog ram for susceptibility to high FFA at one southern Ontario location ap peared to be predictive of FFA levels at other southern Ontario locati ons. Selection of cultivars that have low FFA levels should reduce the FFA problem in Ontario-grown spring canola.