SERF: Harvest Crop Management Strategies of Straight Cutting, Desiccation, Pushing and Swathing in Argentine and Polish Canola on the Effects of Yield Characteristics

Date: March 2009
Term: 3 years
Status: Completed
Researcher(s): Scott Chalmers and Garth Johnston, South East Research Farm (SERF) Redvers, SK
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: n/a

Project Summary

Researchers in Saskatchewan conducted a three-year trial from 2006 to 2008 to assess the potential of pushing canola as a pre-harvest management option compared to swathing, pushing and/or desiccating, and straight cutting canola. In summary, pushing Argentine canola appears to be beneficial as a late treatment similar to the current recommendations of swath timing and can produce similar yield characteristics as straight cutting and swathing. However, due to mechanical problems no consistent results could be drawn from this 3 year trial and additional studies need to be conducted.

Swathing has typically been the main pre-harvest canola management strategy on most Canadian farms. However, other alternative strategies such as straight cutting, desiccation and pushing are also being used. Pushing is a potential replacement for swathing where pod movement is restricted by mechanically lodging the crop and letting the crop mature while still attached to the root system. Pushing canola has shown to increase yields by 20%, possibly reduce shattering losses, reduce green seed counts and improve overall grade, and eliminate the need of expensive equipment that may break down in the field. Previous research results on pushing canola at different locations had contradictory results.

Researchers at the South East Research Farm (SERF) near Redvers, Saskatchewan conducted a three-year trial from 2006 to 2008 to assess the potential of pushing canola as a pre-harvest management option compared to swathing, pushing and/or desiccating, and straight cutting canola. The objective of the trial was to assess the similarities and differences among data means for green seed count, thousand kernel weight, and net yield in both Polish and Argentine canola.

In each of the three growing seasons, replicated plots were direct seeded with either Invigor 5020 LL (Argentine canola) or ACS-C7 (Polish canola) in early May. In 2008 due to a shortage of Polish seed varieties, only the Argentine canola plots were planted. The treatments on the various plots included: check (straight combine), desiccated and straight combine, early pushing, late pushing, swathing, early desiccation followed by early pushing and late desiccation followed by late pushing. Some plot treatments were desiccated with Reglone at a rate of 0.7 L/ac.

Figure 1. SERF fabricated a pusher with a cutting bar attachment to “swath” canola plots. The cutting bar attachment was removed for the pushing operation.Pushed plot treatments were pushed with an existing piece of equipment manufactured from Ag Shield Manufacturing (Benito, MB) mounted on a 595 Allied front-end loader of a Ford 3750 tractor. Early pushed crops were pushed 7-10 days before typical swathing stage (50-60 % seed color change). Swathing and late pushing commenced at the same stage. Desiccation during pushing began during the stage of pushing mentioned earlier. Plots were harvested with a Winterstieger Nursery Elite combine when seed is at a dry storage condition. Data collected from each sample included green seed count (percent out of 500 seeds), moisture, harvest weight and thousand kernel weight (MKWT).

The study results from 2006 suggest that Polish canola had no significant differences in yield characteristics with the various pre-harvest management treatments. However, Argentine canola showed significant yield, thousand kernel weight and green count differences. Yields were best for swathing, but were not significantly different from a late push or straight cutting. However, swathing was significantly higher yielding in comparison to an early push. When pushing was followed by desiccation, yields appear to become frozen when desiccated compared to non-desiccation pushes. This indicates that plants continue to mature to their fullest similar to straight cutting allowing the plant and seed to fully mature while still pushed to the ground. Green count was found to be in significantly higher counts in desiccated plots than in pushed, swathed and straight cut plots. No differences in swathed and pushed plots were found.

The 2007 and 2008 results were negatively affected by harvesting equipment. Design problems with the pusher/swather are the most likely explanation for the poor yield data. For example, tire damage to the 6-8 inches behind the pusher and damage to adjoining plots both from “leaning” plants being crushed to the ground and plugging of the swather mode of the implement tearing plant from adjoining plots caused reductions in yield.

In summary, pushing Argentine canola appears to be beneficial as a late treatment similar to the current recommendations of swath timing and can produce similar yield characteristics as straight cutting and swathing. The pushing treatment is most effective when there is enough plant mass to “knit” together and provide enough plant mass for the canola to hold together and provide enough weight or the canola to stay “pushed.” However, due to mechanical problems no consistent results can be drawn from this 3-year trial. Additional studies should be conducted to further evaluate canola preharvest crop management strategies.

Figure 2. 2006 Illustration of final yield and thousand kernel weight for various preharvest management strategies in Argentine canola.

Figure 3. 2006 Percent green count (from 500 seed sample) resulting from various preharvest management strategies in Argentine canola.

Full Report PDF: n/a