Excess moisture effects on Canola growth and yield
Canadian Agricultural Partnership funding
Curtis Cavers, AAFC Portage la Prairie
The purpose of this project is –
1) 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.
2) To find out how timing of excess moisture stress affects yield.
Canola grew shorter in plots where flooding stress was imposed at later crop stage. Flooding stress at early crop stage resulted in delayed maturity. Grain yield was severely affected when plots were flooded at later crop stage. This might not be only due to flooding effect as these plots also showed severe root rot symptoms after flooding stress. Variety-flooding interaction was not significant for the grain yield. All canola varieties were able to tolerate flooding stress at the early crop stage. No Canola variety, however, exhibited flooding tolerance when plots were flooded at later crop stage.
Extreme moisture in Manitoba soil causes significant losses to farmers. Canola is quite susceptible to water logging and shows a yield reduction if exposed to excess moisture in 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.