Features Agronomy Tillage
Weekly report on canola yields few positives

May 14, 2009

Unseasonably cool and dry conditions prevailed across the prairies last week. Spotty rainshowers and a few snow flurries meant additional moisture was received but these events were quite localized.

As a result, soil moisture conditions continue to range from poor to excess.

In Manitoba, much of the Red River Valley (approximately 96,000 acres) still remains submerged under the swollen Red River, although water levels have receded 7 feet from the peak. The rest of Manitoba has good to adequate moisture.

In Saskatchewan, soil moisture conditions range from dry to adequate. In southern Saskatchewan, it continues to be dry north of #1 highway and west of Gravelbourg. Seeding is continuing in these areas but germination will likely not occur until precipitation is received. Soil moisture conditions are extremely dry in the Major and Kerrobert areas where soil moisture probes will only reach a two-inch depth in some fields. Conditions also continue to be dry in the thin-black soil zone around Unity, Marshall and Cutknife where soil moisture probes reveal less than a foot of moist soil. Canola seeding is progressing and seeds may germinate but will require additional precipitation shortly. Some producers believe it is too dry to seed canola and are waiting for conditions to improve.

In eastern Alberta, the dry pocket around the Coronation, Consort, Sedgewick areas still exists. Seeding is continuing in this area but slowly as producers wait for conditions to improve. Across the remainder of Alberta there is growing concern about the rapidly depleting soil moisture. Seeding operations are continuing but additional precipitation is needed very soon.

Seeding operations progressed late last week and over the weekend. Where conditions are wet, acres are being seeded on a field by field basis. Seeding in the wetter areas is probably five to 10 percent complete. In the drier areas, seeding of cereals and pulses is nearing completion and seeding of canola is becoming more general this week with some producers having more than 50 percent already seeded.

Less Than Ideal Conditions
Surface soil moisture is rapidly depleting in many regions and soil temperatures remain cool. In many areas, frost is occurring nightly. These conditions are extremely stressful on canola seedlings and will affect germination and emergence. Unless conditions improve, assuming only about 50 percent of the seeds planted will result in a healthy seedling as a best-case scenario, should be a reasonable estimate for calculating appropriate seeding rates. Recognizing that yield potential starts to drop when seeding is delayed after mid-May, what can be done to maximize seedling survival prior to planting?

If seeding early into cold, dry soils consider the following strategies:
• Chasing moisture is not the way to go. Seed shallow and wait for spring rains.
• Target a consistent seeding depth of one half to one inch. It may be necessary to slow down to achieve this consistency.
• Because of changing soil conditions and the potential for mechanical issues with drills, check the seeding depth periodically, particularly when moving field to field.
• Maintain a reasonable seeding rate or potentially bump seeding rates up by 10 percent. 
• Canola seed size can be quite variable. Take note of the seed size (TSW should be marked on seed tags or seed bags) and adjust seeding rates accordingly. 
• Place fertilizer (in safe amounts) near the seed to optimize efficiency.

Keep good records
Now is the time of year to have a pen and paper handy. Keep good records. Write things down while details are still fresh. Note things such as seeding date, rate, fertilizer applied, herbicides applied, etc. Always keep a seed sample and the blue seed tag from each variety and seed lot sown. Store stamples in a paper or cloth bag in a cool, dry place. Keeping records and seed samples can help if/when diagnosing an issue later in the season.

Frost on Emerged Canola

Frost has been reported regularly and the forecast for the coming days remains cool with over-night frost in many areas. If canola has emerged, remember a proper assessment of frost damage can’t be made for several days, until it can be determined if new growth is appearing on damaged plants. One benefit of the growing conditions this spring is that they have been conducive to acclimatizing canola seedlings. These cool growing conditions may help the tiny seedlings tolerate light frosts.

For more information on canola seeding and other agronomic details, go to the respective websites for the provincial agriculture ministries or go to www.canola-council.org/