Canola As a Winter Crop for California – Experiences, Potential and Future Directions.

In this presentation we describe our research related to evaluating canola as a winter crop for California. California has the most valuable agricultural sector in the United States however this could be jeopardized by increasing temperatures and reduced irrigation water availability. A proposed adaptation strategy involves the increased use of cool-season crops that can be grown during times of lower evaporative demand and use rainfall rather than irrigation. The majority of field-crops available to California growers are warm-season species, so a niche exists for new cool season crops. Canola (Brassica napus) is well-placed to fill this niche. Successful canola industries in climatically similar regions of southern Australia suggest the crop may be well-adapted to California. Californian growers can take advantage of both food-grade and biodiesel markets for canola oil, and the state’s livestock industry is a potential market for canola seed meal. Because canola can also be used as forage, there may also be opportunities to use canola as a dual-purpose crop. Surprisingly, despite this potential and intermittent field evaluation since the late 1970s, there is little commercial canola production in California at the present time. We have evaluated canola in California since the mid-2000s. Our work has found surprisingly high yields, although yields vary significantly between sites, agronomic management methods, and varieties. This demonstrates canola has excellent yield potential in the state, but further variety evaluation and agronomic studies are required. In this presentation we give our findings and also discuss our use of spatially-optimized partially-replicated trial designs, the use of mixed model analysis via ASREML-R, and the use of field data to evaluate the APSIM crop model.