18th Congress of the European Society for Agronomy

Climate change impacts on canola growth and yield characteristics: challenges and opportunities

Not scheduled

15m

Les Dortoirs (1st floor) (The Couvent des Jacobins)

Poster Synergies between researchers, society and farmers Poster session #1

Speaker

Mr Andries Le Roux (Department of Agronomy, Stellenbosch University, Stellenbosch; Elsenburg Agricultural Training Institute, Department of Agriculture, Western Cape Government)

Description

1. Introduction
   Climate change is caused by the increase in atmospheric greenhouse gases, which leads to rising temperatures. This, in turn, alters rainfall amounts and distribution patterns, which will affect canola growth and yield characteristics. A systematic literature review was conducted to investigate the influence of changing climatic factors on canola growth during its vegetative stage and canola yield development through its reproductive stage.
2. Materials and Methods
   Twenty-two peer-reviewed journal papers were selected following the screening of 2055 papers according to the climatic factor’s effects on canola growth and canola yield characteristics. All factors were compared to the control within the study and expressed in a percentage.
3. Results
   During its vegetative growth stage, canola growth responded positively to an increase in CO2 concentration by improving the carbon assimilation rate by, on average, 40%, which resulted in plants producing 58% more biomass. If temperatures were closer to the optimum (i.e., 20-25 °C), biomass production improved, with colder temperatures (5 °C) having a greater impact on the biomass (34% reduction) (Rahman et al., 2020) than extreme hot conditions (34 °C) (9% reduction) (Pokharel et al., 2021). Moderate soil moisture stress caused an average reduction in leaf area of 41% (Uddin et al., 2018), a 44% reduction in stomatal conductance, and a decrease of 17% in evapotranspiration. Climatic factors mostly affected canola seed yield during its reproductive growth stage. Elevated CO2 improved the seed yield by on average 38% (Uddin et al., 2018). Daytime temperatures above 28 °C (heat stress) caused canola flower abortion and resulted in a 16% reduction in pollen viability (Wu et al., 2020), which ultimately led to an 84% decrease in seed yield (Elferjani et al., 2018). Heat stress also reduced the oil extraction by 50% (Elferjani et al., 2018). Soil moisture stress during the flowering stage resulted in a 43% reduction in seed yield, on average, and an oil extraction reduction of 36%. Soil moisture stress during the seed fill stage had the same effect, but to a lesser extent; a 22% reduction in seed yield and an oil extraction reduction of 27% were observed.
4. Discussion
   This literature-based study illustrates that: i) the effect of rising atmospheric CO2 concentration has a fertilising effect on canola growth and production; ii) increased heat stress occurrence during the reproductive growth stage has a greater effect on production than heat stress during the vegetative growth stage; iii) the effect of drought stress during the reproductive stage is detrimental to canola production; iv) elevated atmospheric CO2 concentration may offset the yield limiting effects of heat and drought stress during the vegetative and reproductive growth stages.
5. References
   Elferjani, R., & Soolanayakanahally, R. (2018). Canola responses to drought, heat, and combined stress: shared and specific effects on carbon assimilation, seed yield, and oil composition. Frontiers in Plant Science, 9(2018), 1224. https://doi.org/10.3389/fpls.2018.01224
   Pokharel, M., Stamm, M., Hein, N. T., & Jagadish, K. S. V. (2021). Heat stress affects floral morphology, silique set and seed quality in chamber and field grown winter canola. Journal of Agronomy and Crop Science, 207(3), 465–480. https://doi.org/10.1111/jac.12481
   Rahman, M. N., Hangs, R., & Schoenau, J. (2020). Influence of soil temperature and moisture on micronutrient supply, plant uptake, and biomass yield of wheat, pea, and canola. Journal of Plant Nutrition, 43(6), 823–833. https://doi.org/10.1080/01904167.2020.1711941
   Uddin, S., Parvin, S., Löw, M., Fitzgerald, G. J., Tausz-Posch, S., Armstrong, R., & Tausz, M. (2018). The water use dynamics of canola cultivars grown under elevated CO2 are linked to their leaf area development. Journal of Plant Physiology, 229(July), 164–169. https://doi.org/10.1016/j.jplph.2018.08.001
   Wu, W., Shah, F., Duncan, R. W., & Ma, B. L. (2020). Grain yield, root growth habit and lodging of eight oilseed rape genotypes in response to a short period of heat stress during flowering. Agricultural and Forest Meteorology, 287(January), 107954. https://doi.org/10.1016/j.agrformet.2020.107954