Canola Planting Date Study

Objective:                  

To identify the optimum planting dates and varieties of winter canola to ensure winter survival and high yield potential in northwestern Montana

Personnel:                 

Clint Beiermann, Jessica Pavelka                

Summary:

Six varieties of winter canola were planted at three planting dates: August 15^th, September 1^st, and September 15^th of 2020. They were managed using irrigation and all were harvested on August 11^th of 2021 (Table 1).

Yield was affected by planting date and canola variety. Canola planted on August 15 and Sep 1 yielded 105 bu/A and 103 bu/A, respectively, outyielding canola planted September 15. Average yield decreased as planting was delayed beyond August 15 with the highest average yield at 105 bu/A for August 15 to the lowest average at 96 bu/A for September 15 (Table 2, Figure 2). Within the August 15 planting date the varieties CP1022WC, P_Quartz, and R_Mercedes were the highest yielding. Within the September 1 planting date P_Quartz, R_Mercedes, and R_PluraxCL were the highest yielding varieties (Table 2).

Canola survival rate during the overwinter period was affected by planting date. Canola planted on August 15 and September 1 suffered stand reduction near 20% (Table 4). Canola planted on September 15 resulted in significantly poorer survival and 41.6% stand reduction was observed during the overwintering period.  

Oil content is generally high for all varieties planted in the study, with oil content values ranging from 47.4% up to 51%. Oil content was affected by variety with R_Mercedes having the highest oil content at 51.2% (Table 3).

Based on our first season results, planting dates between August 15^th to September 1^st would be optimum to establish winter canola in northwestern Montana. Repeated years of research on this study will strengthen results.

Figure 1

Winter canola yield by planting date

Figure 2

Regression of yield for 30 days after August 15th planting date