Flooding effects on canola growth and yield
Canadian Agricultural Partnership funding
Curtis Cavers, AAFC Portage la Prairie
- To quantify the tolerance and recovery of current cultivars of canola to excess moisture stress, with the intention of identifying a cultivar that has improved tolerance.
- To find out how timing of excess moisture stress affects yield.
Flooding at the early crop stage resulted in taller plants, delayed maturity and greater canola yield. However, no yield was obtained when plots were flooded at later crop stage. These plots were severely infected by root rots after flooding. All canola varieties benefitted similarly, when crop was flooded at the early crop stage. The year 2021 was a drought year and the control plots only produced 4 bu /acre. The soil moisture was deficit during the whole crop season and early flooding actually benefitted the crop by supplying adequate moisture.
Excessive soil moisture conditions cause significant losses to farmers in Manitoba. Canola is quite susceptible to water logging and shows a yield reduction if exposed to excess moisture during the earlier phase of crop growth. Wet soils cause an oxygen deficiency, which reduces root respiration and growth (Canola Council of Canada). This attributed to reduced nutrient uptake in canola. Zhou and Lin (1995) reported that plant height, stem width and the number of primary branches per plant were decreased by waterlogging at seedling and floral bud appearance stages of canola. Pods per plant and seeds per pod were also reduced, giving 21.3% and 12.5% decrease of seed yield from the control for treatments at the seedling and floral bud appearance stages, respectively. No significant difference in seed yield was observed between the control and treatments applied at flowering and pod formation stages.