Gan: Improving Canola Establishment and Uniformity Across Various Soil-climatic Zones of Western Canada
Date: March 2013
Term: 3 years
Status: Completed
Researcher(s): Yantai Gan, Agriculture and Agri-Food Canada (AAFC) Swift Current SK, Eric Johnson, AAFC Scott SK, Randy Kutcher, AAFC Melfort SK, Bill May and Guy Lafond, AAFC Indian Head SK, Neil Harker, AAFC, Lacombe AB, Byron Irvine, AAFC Brandon MB and Rob Gulden, University of Manitoba
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: n/a
Project Summary
Researchers with AAFC conducted a three-year study to determine the effect of various degrees of seeding uniformity and non-uniformity on canola plant establishment and seed yield in various soil-climatic zones. They also evaluated the effect of seed vigour and straw management options on plant establishment and crop yield in canola. The results showed that total precipitation and temperature differences had significant effects on seed yield and number of fertile pods. Uniformity was most important when plant density was at or below 40 plants per square meter. The results also showed that plant establishment, weed spectra and density, and canola yield were impacted by the different stubble effects.
Producers in western Canada often experience poor and non-uniform stand establishment in their canola crops. Low plant stand decreases the competitiveness of the crop to weeds and decreases crop yield, while non-uniform plant stand reduces plants’ ability to tolerate heat and drought stresses during the mid-summer. Poor and non-uniform stand can be caused by many factors, but more information is needed to quantify how a uniform and optimized plant establishment can be achieved. If the emergence rates can be improved by 10%, which is highly achievable, the saving for seed alone will be about $20 million annually.
Researchers with Agriculture and Agri-Food Canada (AAFC) conducted a three-year study from 2010 to 2013 to determine the effect of various degrees of seeding uniformity and non-uniformity on canola plant establishment and seed yield in various soil-climatic zones. They also wanted to evaluate the effect of seed vigour and straw management options on plant establishment and crop yield in canola. The three-year project included two field experiments at various sites in western Canada totally 17 site-years. In 2010, 5 different sites were selected (Swift Current, Melfort, Carman, Lacombe and Brandon); and 6 different sites were selected for 2011 and 2012 (Swift Current, Melfort, Carman, Lacombe, Morden and Indian Head).
Experiment 1:
In experiment 1, uniform and non-uniform plant establishment for plant stands of 100, 80, 60, 40 and 20 plants per square meter were compared. Plant stands were hand-thinned at the three-leaf stage to create uniform and non-uniform plant stands. Soil samples were taken at 0-15 and 15-30 cm over the entire trial area.
The results of experiment 1 showed that the total precipitation during the whole growing season had significant effects on seed yield and total number of fertile pods (i.e., pods with at least one seed) of canola. As well, temperature differences during the growing season showed large effects on both fertile and infertile pod (pods with no seed) formation. At high-yielding sites, emerged plants had a survival rate near or greater than 100% over the growing season, compared to average-to-low yielding sites, where the survival rate of the emerged plants was generally around 80%.
In general, seed yield and number of fertile pods of canola increased with increasing plant population from 20 to 100 plants per square meter of all site-years. Overall, canola seeded with uniform-planting configuration produced 13% greater seed yield than non-uniform planting at low-yielding sites, 14% at average-yielding sites and 7% at high-yielding sites, when the plant density was at or below 40 plants per square meter. However, when the plant density was greater than 40 plants per square meter, uniform and non-uniform plantings resulted in similar seed yield. The results also showed that fertile pods grown at the different positions of canola plant can impact seed yield differently. Based on the study results, pods grown at the bottom one-third of canola plant showed a closer relationship to the seed yield compared with pods grown at the top one-third of the plant.
Experiment 2:
In experiment 2, four residue management options (20 to 30cm standing stubble, 40cm tall stubble +spring mow<5cm, <10cm stubble-straw chopped, and <10cm stubble-straw removed) and three seed vigour options (120 high-vigour seed, 120 low-vigour seed and 80 high + 40 low-vigour seed) were compared. Soil samples were taken at 15-30 cm over the entire trial area.
The study results showed that plant establishment, weed spectra and density, and canola yield were impacted by the different stubble effects. In particular, the “<10cm stubble-straw chopped” pattern restricted days to 10% flower, days to end of flowering and days to maturity of canola compared with other management methods, particularly in Swift Current and Carman. However, the effect of straw management options on canola establishment and seed yield was inconsistent across the different sites and years. The harvest index varied greatly, depending on environment conditions.
Generally, the results showed that seed vigour can influence canola growth, time to flowering and maturity; and had a significant effect on canola yield. High vigour seeds showed better emergence at Carman, Lacombe and Swift Current, however in Lacombe low vigour seeds reached maturity faster than high vigour seeds, which may be due to the different environmental effects at the Lacombe from other locations.
Canola yield was influenced by straw management and seed vigour. Although straw management did not affect fertile pods numbers, the pattern of “40cm tall stubble +spring mow<5cm” showed less infertile pods numbers compared with other management methods, especially for Carman 2012 and Lacombe 2011. The number of fertile pods was also significantly affected by canola seed vigour in all trials.
Straw management had significant effects on pre-spray broadleaf weed spectra and density, with taller stubble patterns reducing broadleaf weed numbers more than other straw management. However, straw management had a lesser effect on grassy weeds, with the “<10cm stubble-straw removed” pattern showing the lowest ability for inhibiting grassy weeds of all management methods.
Fig.1 Stubble effects on plant establishment and development. Blue bar: <10cm stubble-straw chopped; Red bar: <10cm stubble-straw removed; Green bar: 20 to 30cm standing stubble; Purple bar: 40cm tall stubble +spring mow<5cm. (Small bars on top of bar charts are standard error; lower case letters indicate significant differences between treatments at the given site; sites with no lettering indicated no differences between treatments at the given site.)
Full Report PDF: n/a