The Growing Point | July 2019

Early bird gets the germ: Spring wheat trials at CanolaPALOOZA

This year, the Alberta Wheat Commission sponsored and participated in one of the top agronomy events in Alberta, CanolaPALOOZA. Hosted by Alberta Canola, the event was a great success with hundreds of producers and agronomists coming out to chat with industry experts about various agronomic topics.
















Alberta Wheat team at CanolaPALOOZA along with Dr. Brian Beres in front of his plots. Back L-R: Leora Cohen (Agronomy and Producer Engagement Intern), Janine Paly (AWC director), Brian Beres, Brian Kennedy (grower relations and extension manager) Front: Jeremy Boychyn (agronomy research extension specialist) 


The spring wheat booth at CanolaPALOOZA this year highlighted the ultra-early seeding (UES) research led by Brian Beres of Agriculture and Agri-food Canada (AAFC) (Figure 1) and partly funded by the Alberta Wheat Commission. Two commonly used varieties of spring wheat (Stettler and Brandon[JB1] ) were seeded at different soil temperatures to demonstrate the effects of seeding date based on soil temperature on plant growth (Figure 2). Dr. Beres also compared seeding density and depth to demonstrate the effects of how high:low densities and depth can alter emergence, vigor, competitiveness and harvest dates.

 
















Stettler wheat seeded at 4°C soil temperature (left) and 9°C soil temperature (right) at 400 seeds/m2


For those who didn’t make it out to the event, some common questions we received about ultra-early seeded (UES) spring wheat are included below.


When should I seed UES wheat?

The plots were not seeded on a specific calendar date, but rather a prescribed soil temperature—between 2-6°C, was used as the trigger to begin planting.  Dates of target soil temperatures can vary from year to year, and in extreme cases may vary from February to April in some parts of the province. To date, not yield drag has been observed with planting in soils as cold as 2°C, even 0°C, as long as the soil surface is not frozen.  Management strategies such as high planting densities, dual fungicide:insecticides, and seeding depths of about 4 cm provide a system for ultra-early plantings that may improve grain yield compared to delayed plantings of 7 – 10 °C.

At what rate should I seed UES wheat?

Wheat benefits from a higher seeding rate due to the cooler soils inherent in UES. Trials showed the greatest benefit of seeding rates at 400 seeds m-2 (40 seeds ft-2) when using clean, disease free seed with a germination rate >90%.

How many pounds per acre or bushels should I be seeding at to get 400 seeds m-2?

It depends upon the Thousand Kernel Weight (TWK) of the variety you are seeding. Using a seed rate calculator (https://www.agric.gov.ab.ca/app19/loadSeedRateCalc) can help you get the plant stand you planned for.

Why is number of seeds per area used for seeding rate?

Variability in seed size between varieties or seed lots can lead to substantial differences in number of seeds you are planting per acre when only using weight to determine your seeding rate. For example, there are almost 3000 more kernels in a pound if the TKW is 35g than if the TKW is 45g. If you are seeding at 115 lbs/ac with the larger seed, you are only putting down 286 seeds/m2 (28 seeds/ft-2), rather than 368 seeds/m2 (36 seeds/ft-2) with the smaller seed.

Is there a risk of frost and how will it affect the wheat seedlings?

Yes, there is always a risk of frost when seeding wheat. There is an increased risk when seeding earlier in the season as compared to later. For this reason, you are at a slightly higher risk and it is important to consider your risk tolerance. To help combat this, Dr. Beres recommends using a dual seed treatment with UES wheat. The seed treatment will help protect against the abiotic stresses that come with UES. Keep in mind, wheat seedlings up to about the 5-6 leaf stage can survive -8°C frost. You may lose some leaves, but the wheat plant will recover.  For example, frost damage was widespread this year; however, only partial damage to leaves was observed and there is no indication canopy development and yields will be negatively affected.

Will I be able to harvest UES wheat earlier?

Yes! The UES wheat will be harvested earlier than wheat seeded at higher soil temperatures. The difference between the two depends on various early season variables including genetics, environment, and management style. Early bird gets the germ!

 View the Alberta Seed Guide here.