PERFORMANCE OF INTER-CULTIVAR SUMMER TURNIP RAPE HYBRIDS IN SASKATCHEWAN

The agronomic performance of inter-cultivar hybrids of Brassica rapa L . was studied in crosses between four B. rapa cultivars. Six reciproca l hybrid combinations were produced by hand pollination in the greenho use. Hybrids and their parents were tested in replicated yield tests f or 3 yr. An average, over all hybrid combinations, of 13% heterosis fo r seed yield was observed. Heterosis for seed yield was greatest in cr osses between genetically diverse cultivars, which agrees with classic al theories on heterosis. There were also significant differences in y ield of reciprocal F, combinations. Seed oil content was not heterotic . The results of this study indicated that the level of heterosis of s eed yield in crosses between B. rapa cultivars adapted for production in western Canada is sufficient to warrant the development of a suitab le pollination control system for hybrid B. rapa production.