Kirkland: Management of Fall and Early Spring Seeded Herbicide Tolerant Canola in the Prairie Region
Date: April 1999
Term: 3 years
Status: Completed
Researcher(s): Dr. Ken Kirkland, E. Johnson, Agriculture and Agri-Food Canada, Scott, SK
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: AAFC Matching Investment Initiative
Project Summary
The Scott Research Farm began to reevaluate fall seeding in 1993 after the introduction of herbicide tolerant canola cultivars. Numerous studies were conducted at Scott from 1996 to 1998 to evaluate the effect of fall and early spring seeding of herbicide tolerant canola. The results showed that fall seeded canola yielded 95% and 153% of early spring and mid-May seeded canola respectively. There were also several benefits to both fall and early spring seeding. From the studies, researchers provided several preliminary recommendations for fall seeding for producers.
The potential of fall seeded canola was shown in studies conducted at the University of Saskatchewan in the 1970s. However, winter annual weeds and the risk of fall germination were a problem. Agriculture and Agri-Food Canada’s Scott Research Farm began to reevaluate fall seeding in 1993 after the introduction of herbicide tolerant canola cultivars. The risk of fall germination was still a concern.
Numerous studies were conducted at Scott from 1996 to 1998 to evaluate the effect of fall and early spring seeding of herbicide tolerant canola. Researchers had several objectives including: determine the seeding dates on canola maturity, yield and quality, and the risk levels associated with each seeding date (Fall – October; early spring – late April, early May, mid-May and late-May). Researchers also wanted to determine the effect of seeding methods, comparing in soil versus broadcast in fall and early spring; stubble versus fallow in the fall and direct seed versus conventional. They also studied soil nutrient management, weed management strategies and volunteer control management in succeeding crops.
The results showed that fall seeded canola yielded 95% and 153% of early spring and mid-May seeded canola respectively (Table 1). This was calculated by averaging the yields of best agronomic treatment from each of the seed date experiments, and included three studies in which establishment of fall seeded canola was poor due to soil crusting or wind damage on fallow. Fall and early spring seeding resulted in early maturity, high seed oil concentration and large seed size. Early maturity avoided late season environmental stress as well as late season insect attack. It also reduced the risk of fall frost damage to immature seed. Fall and early spring seeded canola, if acclimated to cool air temperatures, survived spring frosts as low as -8C.
Table 1. Yield of Canola Seeded at Three Seed Dates, Scott 1996-1998.
*mean of 13 experiments from 1996-98 – includes 3 experiments in which fall seeded canola established poorly on tilled follow.
** mean of 10 experiments from 1996-98.
From the studies, a number of preliminary recommendations for fall seeding were developed for producers.
1. Seed as close to freeze-up as possible. In the moist dark brown, black and grey soil climatic zones, set a target seed date near October 31, while in the brown soil zone set a target date of November 5 to 7.
2. Seed at normal seeding rates. Studies at Scott indicated a 6.7 kg/ha seed rate for Argentine canola is adequate.
3. Seeding a herbicide tolerant canola is recommended since winter annual weeds can be easily controlled with post-emergent herbicides.
4. Use seed treated with a broad spectrum fungicide (Vitavax RS, Premiere Plus, etc,), which can make a dramatic improvement in crop establishment.
5. It is best to place the seed one-half to one inch deep in the soil. Broadcast seeding has caused variable emergence particularly if the soil surface is dry. Deep seeding can also reduce emergence and yields.
6. Best results have been obtained when seeding into standing stubble or chemical fallow. Seeding on tilled fallow increases the risk of soil crusting and wind damage in the spring. Avoid fields that are prone to surface crusting or spring flooding. Problems were encountered at Melfort when using disk openers on heavy clay soils with high levels of crop residue.
7. Seed place or side-band phosphorus fertilizer at soil test recommended rates. Nitrogen fertilizer can be banded prior to seeding, side banded at seeding or broadcast in early spring. If seed placing N, do not exceed provincial recommendations for spring seeded canola. Sulphur is also an important nutrient for canola production and can be applied at seeding or broadcast in the spring using a readily available sulphate fertilizer formulation.
8. Watch emergence closely in the spring. Keep an eye out for flea beetles if afternoon air temperatures are greater than 15C. If flea beetles destroy more than 25% of the cotyledons, treat with a foliar insecticide.
9. Emergence of the fall-seeded crop normally occurs in late April. A thin stand (10 to 20 plants/m2) can produce good yields if the plants are distributed evenly.
10. Spray for weeds early (1 to 2 leaf stage). The primary weed problems in fall seeded canola are winter annuals (stinkweed, flixweed, shepherd’s purse) so early control is necessary. One herbicide application is normally sufficient since the fall-seeded crop competes well with late emerging weeds.
Scientific Publications
Kirkland, K. J. and Johnson, E. N. 2000. Alternative seeding dates (fall and April) affect Brassica napus canola yield and quality. Can. J. Plant Sci. 80: 713-719.