By Elmer Kaskiw, MAFRD

Due to the lack of available stubble this fall, growers may not have been able to seed winter wheat. One option growers may want to consider on a trial basis is dormant seeding.

The dormant seeding of winter wheat is a relatively common practice for anyone trying to grow winter wheat in southern Alberta. This is due to the fact that fall seeded winter wheat can be impacted by Chinooks and warmer temperatures in mid-to-late winter can prematurely bring the crop out of dormancy resulting in winter kill if there is a return to colder temperatures. Similarly in southern Ontario, winter wheat is often dormant seeded on soybean stubble.

If harvest is delayed, growers can often dormant seed winter wheat well into late November and early December. Over the last number of years we have followed winter wheat crops that were both unintentionally and intentionally dormant seeded. In 2012, it was because of the very dry fall and in 2013 it was due to delayed rainfall and a rapid cool down in soil temperature.

In both events it is estimated that perhaps 30-40 per cent of a 2.25 bushel seeding rate actually emerged. In both years, the vast majority of the seed, which germinated, did not survive the winter. The un-germinated seed did vernalize and went on to produce a viable crop that in 2012 yielded similar to the record spring wheat yields of 60-70 bushels per acre. In 2014 and 2015, we have had winter wheat seeded intentionally in the last week of October and have had good success with yields in 2015 surpassing both traditional winter wheat seeding and spring wheat yields.

Some observations and suggestions that might improve the success of dormant seeding winter wheat include:

• Choose fields that do not have a lot of standing water late into the spring as these areas will not survive dormant seeding.
• Be sure to target fields that have good straw and residue management at harvest. This may mean a heavy harrow or conservation tillage pass to better move or incorporate chaff or straw piles as these areas will slow spring germination.
• Delay seeding into the last week of October or once soil temperatures fall below 5 degrees Celsius.
• Seed at 2.25-2.5 bushels using a seed treatment with insecticide and only phosphate seed place since seed will be emerging slowly under cool spring soil temperatures.
• Seed with a narrow opener and on row packer into standing stubble that leaves a defined trench for better snow melt and moisture accumulation.
• Seed at slower speeds especially under dry soil conditions since this will result in reduced shank chatter and better overall seed placement.
• Seeding depth needs to be deeper than winter wheat or fall rye seeded for a traditional fall emergence. Seeding depths of 1.5-2 inches is required since frost heaving will push seed closer to soil surface and the top inch of soil will be subject to freeze drying in early spring. Seed placed at shallower depths will leave it stranded near the surface in a dry pulverized soil that will quickly dry out even after moderate spring rainfall.
• Consider split applying N requirements with half banded in fall and the other half dribble banded in the spring as plants will be slow to access fall bands in spring.
• Check over air seeder for worn or brittle hoses as these will be subject to increased breakage under cold temperatures. Have seed and fertilizer ready for seeding now so that you just have to load and seed without delays.
• Since emergence will be similar to spring cereals, a wild oat herbicide will typically be required in the spring.

Note from WWWI: Dormant seeding winter wheat could, but may not, provide the 15 to 40 per cent yield advantage growers typically experience. Growers also need to be patient in the spring with dormant seeded winter wheat as it will take much longer to fill in than winter wheat seeded that achieved desired top growth last year. There may also be crop insurance implications (i.e. dormant seeded winter wheat will not qualify for a re-seeding benefit in Manitoba).