Strategies to improve field establishment of canola: A review

Good field establishment provides the foundation for a productive crop. Achieving an adequate seedling population ensures the crop forms an effective canopy to capture light and compete with weeds, and an effective root system for uptake of water and nutrients. Canola (oilseed rape; Brassica napus L.), the world's third largest oilseed crop, commonly fails to establish effectively in many regions, which limits yield potential and increases agronomic costs to control weeds, diseases and pests. In the worst cases, crops must be re-sown at significant cost. Despite the evidence for poor establishment in canola globally, the critical soil and plant factors limiting establishment, and opportunities to overcome these are not well understood. Here we review what is known about the factors that contribute to poor canola establishment, focusing on the genetic, agronomic and farming system opportunities to improve establishment. Effective canola establishment is expected to become ever more challenging due to an increasingly variable climate and restrictions in the use of crop protection products. Solutions must integrate breeding, agronomic and seed treatment technologies, and use insights from different canola cropping systems around the world to meet these significant challenges.