Pod Drop and Pod Shatter are Not Closely Related in Canola

Preharvest seed losses in canola (Brassica napus L.) can be substantial and are caused by pod drop and pod shatter. The relative importance of pod drop and pod shatter was determined among a group of hybrid and open‐pollinated canola varieties to better understand these phenomena. Preharvest seed losses in canola were determined by collecting canola seeds (pod shatter) and entire dropped pods (pod drop) from catch trays immediately before direct‐harvesting the plots. Results from correlation analysis showed that pod drop and pod shatter were largely independent. Interestingly, pod shatter was linked primarily to genotype while pod drop was influenced more by the environment. When significant differences were observed, average pod drop was greater in the open‐pollinated cultivars than in the hybrids used in this experiment.