How does in-row seed spacing and spatial pattern affect canola yield?
Term: 4 years, ending March 2023
Status: Complete
Researcher(s): Steven Shirtliffe, U of S; Rob Gulden, U of M
SaskCanola Investment: $409,469
Total Project Cost: $409,469
Funding Partners: N/A
Grower Benefits
This research found that canola yield is maximized when seeding rate and row spacing result in the longest duration of vegetative ground cover.
It also confirmed that existing recommendations to establish 5 – 8 seedlings per square foot with row spacings of 12 inches are adequate to achieve maximum yield.
Project Summary
When it comes to canola seeding rate and row width, think of your crop as a solar panel. Using crop imagery, researchers have found that canola yields are maximized with seeding rates that result in early ground cover that is maintained throughout the growing season. Canola can compensate for lower seeding rates with increasing branching and podding but if that reduction slows canopy closure, or if wide row spacings do not fill in, then yield will be reduced.
The overall hypothesis of this research is that optimal seeding rate and row spacing affect seed yield in canola by maximizing the ground cover through the growing season. To test this hypothesis the study was split into three sub-objectives. The first was to determine plant distribution, survival, branching, ground cover, and yield in response to row width and seeding density. The second sub-objective was to develop and apply image analysis techniques to track space occupied by individual plants over time in different planting arrangements. Finally, the last sub-objective was to study and validate plant growth responses to planting arrangements through simulation modeling.
A replicated, factorial field experiment that varied seeding rate and row spacing over a wide range was used. This research was conducted in 2 x 6 m plots using equipment similar to field scale equipment. It was conducted at Saskatoon (dark brown soil zone, semi-arid climate; Figure 1) and Carman (black soil zone, sub-humid climate) from 2019 – 2022. The growing conditions during these field trials resulted in below optimal seed yield in canola and may have influenced the results. This was due to drought and heat stress that occurred at both the Saskatoon and Carman locations. Despite these stresses and sub-optimal yields, we believe these results are still valid as plant population effects often have greater proportional effects in dry years.
Figure 1. Field site aerial view of row spacing by seeding rate trial on July 18, 2022. Field trial location is Saskatoon. The row spacing varied from 15cm – 90 cm (5.9 - 35.4 in) and seeding rate from 5 – 140 seeds m-2.
To maximize yield in canola growers should seed at least 60 seeds /m2 (5.5 seeds/ft) and have row spacing of 30 cm (12 in) or less. Canola was able to compensate for low seeding rates by increasing branching and number of pods, but this delayed flowering. The row spacing effect was minimal compared to seeding rate however wider row spacings always trended to lower maximum yields than narrower row spacing. Crop yield in canola is highly associated with the space that the crop canopy occupies over time. The highest yielding treatments were the ones that most rapidly achieved and maintained full canopy coverage. The practical agronomic message of this model is that canola yield is not able to compensate for reduced ground cover from poor stands. To manage canola for highest seed yield requires agronomic practices including seeding rates and row spacings, that result in rapid canopy closure.
Full Report PDF: How does in-row seed spacing and spatial pattern affect canola yield?