To investigate whether agronomy can overcome the yield penalty of retained (F2) TT hybrid canola compared with purchased (F1) hybrid seed by using;

• seed mixes.
• increased density or,
• grading to increase seed size.

• Across the trial series at Grass Patch, Ballidu, Merredin and Holt Rock the highest grain yields, oil and gross margins were from the open pollinated variety, so growers should continue to use open pollinated TT varieties in the low rainfall regions, rather than hybrid varieties.
• In the hybrid treatments, there were generally increased yields and oil from the purchased (F1) seed, compared with the retained (F2) seed.  The gross margin was only significantly better at the Grass Patch site, for the 2014 F1 compared with the retained seed. Grading to increase seed size and sowing at a target density of 40 plants/m² improved the yield and gross margins of F2 retained hybrid seed, but at Grass Patch in 2015 using F1 hybrid seed or OP seed provided better results..