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Winter pea and lentil left out in the cold

Over the last five years, researchers at Alberta Agriculture and Rural Development (ARD) conducted field trials to assess the viability of winter pea and lentil in Alberta. Three years of trials started in 2008 and provided insight into where winter pulses were viable and also allowed researchers to develop agronomic recommendations. Plots were seeded in Lethbridge, Brooks, Bow Island, High River, Lacombe and Edmonton in 2008 through 2011, and a fourth year of trials were seeded at Brooks, Bow Island, Lethbridge and High River.

“There is potential for winter pea and lentil in southern Alberta, but a couple things are holding back the adoption,” says Mark Olson, unit head-pulse crops with ARD’s crop research and extension division in Stony Plain. “Pea crops have to be higher paying to get into the rotation under irrigation and we need better varieties that are more adapted to Alberta conditions.”

In the trials, winter pea and lentil yielded equal to or better than spring varieties only at Lethbridge and Bow Island. Near Edmonton, the winter varieties had no winter survivability. And at Brooks and Lacombe, although winter survivability was acceptable, yields were less than 50 per cent of spring varieties.

Winter fababeans are not a good option as they did not overwinter or perform very well in any of the locations. Better varieties are needed for Alberta conditions.

Varieties and seeding rates
The winter pea and winter lentil varieties used in the trials are from USDA germplasm and work done by Dr. Kevin McPhee, a researcher formerly at Pullman, Wash., and now at North Dakota State University. The winter pea varieties that survived in southern Alberta were Specter and Windham. Specter is a small seeded, yellow pea and is semi-leafless and tall (100 cm vine length). Windham is a semi-leafless yellow pea, but shorter than Spectrum and with a small seed.

For winter pea, the research found a seeding rate of 75 plants per square metre provided optimum yields – the same rate as spring pea. Seeding is generally recommended for the first two weeks of September.  

“Seeding winter pea is a little more difficult than winter wheat. Pea seed is larger and it definitely has to be sown into moist ground,” says Olson.  

Another concern is the pea leaf weevil. Winter pea is the first crop to emerge, and is very susceptible to pea leaf weevil. Other than fababeans, winter pea is a preferred host. Seed treatment with Cruiser Max was effective in controlling pea leaf weevil in the following spring.

The winter lentil variety chosen as the best for southern Alberta winters was Morton, developed at Washington State University by Drs. Fred Muehlbauer and Kevin McPhee. Morton grows about 31 cm tall, and is a small seeded variety with a beige seed coat and a red cotyledon. When seeded in the second and third weeks of September, seeding rate is 110 plants per square metre – the same rate as spring lentil.  

Survivability
While winter survivability is important, the ability of winter pea to compensate for lower survivability by tillering means yield is not well correlated to overwinter survivability. Spring growing conditions had a greater impact on yield. Olson says yields of more than 30 bushels per acre were achieved even though survivability ranged from 25 to 83 per cent. The research suggests that acceptable winter pea yields can be achieved if at least 30 plants per square metre (40 per cent survivability) survive the winter. If fields have less than 30 plants per square metre, the field should be reseeded to a different crop.  

Winter lentil showed similar trends as winter pea. Based on the research, fields with less than 60 plants per square metre (55 per cent survivability) should be re-seeded to another crop.

Winter pea had very little disease in the trials; however, the varieties do not have resistance to powdery mildew. Very little disease was observed on the winter lentils during the trials.

Fall and spring weed control can be achieved with fall-applied Edge herbicide. With good stand establishment, further spring weed control may not be required.

Yield and maturity
The winter pea varieties flowered 16 days earlier than spring varieties, but maturity was similar to spring pea about 50 per cent of the time, and one week earlier the other 50 per cent. At Lethbridge, winter pea yielded 39 per cent higher than spring pea, but the same at Bow Island.

Winter lentil flowering was 11 days earlier than spring varieties, and harvest was eight days earlier in two of three years. At Lethbridge and Bow Island, winter lentil yields were 15 to 39 per cent higher than spring varieties.

Where to now?
At Lethbridge, the Farming Smarter applied research farm also conducted research on winter pulses. Farming Smarter managed their own set of trials looking at slightly different agronomic practices only at the Lethbridge location. They conducted a variety trial, herbicide trial, and a seeding date and depth trial along with a pea leaf weevil trial. Subsequently in 2012, 10 acres of Windham winter pea was grown on a dryland piece of the applied research farm. Ken Coles, general manager, says they achieved reasonable yield but harvestability was a bit of a problem, and they should have swathed the winter pea instead of straight cutting it.

“Generally, to have winter pea acres take off, we would need to see slightly better winter hardiness in the varieties. We don’t have any Canadian breeders working on it, but now that Dr. McPhee is working at North Dakota, maybe we will see some better winter hardiness,” says Coles.

At NDSU, Kevin McPhee continues to work on improved winter pea with a lesser effort on winter lentil. He has encountered some disease limitations that are unrelated to the winter trait.

“We have had survival in most years at varying levels. I have learned a lot about the environment here and still have hope that we can make progress improving winter hardiness in peas, especially,” says McPhee.

While research funding is no longer available in Alberta, Coles is continuing with small plots to increase seed supply. “We don’t want to give it up. A lot of people are still interested in the idea of winter pulses. We just need better varieties.”

February 18, 2014  By Bruce Barker

Improved varieties are required before winter pea will catch on. Over the last five years