Faculty of Natural and Agricultural Sciences
Department of Plant Production and Soil Science
Selected Highlights from Research Findings
Canola is most sensitive to water stress during the flowering stage and less sensitive during the vegetative and seed-filling stages. Irrigation resumption after water stress during the flowering stage delayed leaf senescence, enhanced the formation of new flowers, and delayed pod ripening by 114 GDD compared with the non stressed treatment and SNN treatments. Stressing canola during the seed-filling stage caused the crop to mature 127 GDD earlier than the non-stressed treatment. There was a very strong seed yield response to the amount of water used. Water use efficiency, seed yield and oil content, and oil yield were highest for the non-stressed and lowest for the treatment stressed during the flowering stage. Canola production is source limited under well watered conditions; however, it becomes sink limited when stress occurs in the flowering stage. From an irrigation management and biophysical production perspective, in areas with a sufficient water supply it would be advisable to irrigate canola according to crop demand throughout the growing season to ensure highest seed yield, oil content, and oil yield. In contrast, in areas where water scarcity is a crucial issue, high WUE at the expense of some seed and oil yield can be achieved by stressing the crop during the vegetative or grain-filling stages. Nonetheless, the choice of strategy needs to consider a long-term cost-benefit analysis, which takes into account the initial irrigation system capital cost and the running cost (water, labor, and electricity) as opposed to the additional yield gained by additional irrigation.
Contact person: Dr EH Tesfamariam.
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