Management for Maximum Economic Yield of Open Pollinated and Hybrid Canola

Hybrid varieties of canola are new to farmers in western Canada, and there is a lack of understanding as to the level of management and inputs required to optimize yield relative to established open pollinated varieties. Inputs that are seen as critical to optimizing yield include seeding rate (crop establishment), fertility level (N, P, K, and S), and fungicide use for control of white mold (sclerotinia spp.). Research is currently being carried out at three locations in Saskatchewan to evaluate the response of new hybrid and open pollinated canola cultivars to varying these three inputs on crop yield, quality and disease response.

To date, five location-years of data have been collected. Seeding rates lower than recommended generally delayed crop maturity and reduced yield at one location where stand establishment was low. A seed rate by N rate interaction at two location years suggested that higher plant densities might require higher fertility when moisture is abundant. Increased levels of fertility generally increased yield and protein content, although increasing fertility levels above recommended rates did not always increase yield significantly. In 2000, the hybrid variety was consistently higher-yielding than the open pollinated variety. Disease incidence and severity (Blackleg and Sclerotinia) have been low, and fungicide responses have been small or non-existent. In a separate N rate by cultivar trial, the hybrid variety generally yielded more than the open pollinated variety at all N rates. At two of the three locations, yield of the hybrid was maximized at higher N rates than the open pollinated. These results suggest that the hybrid not only used N more efficiently, but required more N to optimize yield. Preliminary economic analyses suggest returns would have been optimized at higher N rates for the hybrid variety at these two locations. SK-24