Seeding considerations for the season

The Ag-Info Centre is receiving more phone calls this year about field pea production than in recent years. Due to clubroot concerns, canola growers are widening their crop rotation by inserting a pulse crop into their cropping plans. Also, because nitrogen fertilizer prices are high and other commodity prices are low, farmers are opting to utilize field pea as a nitrogen fixer and for higher earnings.

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“It is important to select a pea variety that has an erect standability for ease of harvesting,” says Neil Whatley, crop specialist with Alberta Agriculture and Rural Development’s Ag-Info Centre. “Producers should also select a variety that displays very good powdery mildew resistance. Alberta’s Seed Guide is a helpful resource to find these varieties.”

Disease risk should be considered when selecting the proper field to plant field pea. Due to risk of ascochyta blight, field pea should only be planted in the same field once every four to five years. In wetter areas of the province, sclerotinia stem and pod rot is a higher risk when pea is planted after canola. Alberta’s pulse crop specialist, Mark Olson, advises that the other drawback with pea on canola stubble versus canola on pea stubble is that there are no registered fungicide products to control sclerotinia in pea while there are a number of products available to control sclerotinia in canola.

“Since high heat or drought conditions at flowering can abort flowers, field pea should be planted early,” says Whatley. “In much of central Alberta, pea can be planted as early as mid- to late-April because it can tolerate light frosts (-4 to -6 °C). As a general rule, when the top inch of the soil reaches 5 °C, pea can be seeded.”

A target seeding rate to achieve optimum plant population when seeding field pea is seven to nine plants per square foot (75 to 99 plants/m2). Pea is a much poorer competitor with weeds than a cereal crop, so seeding at optimum rates is important to attain peak yields. To attain an optimum seeding rate, use the seeding rate calculator on Alberta Agriculture’s website (www.agriculture.alberta.ca), carefully selecting the proper 1,000 kernel weight for the specific variety. Pea variety 1,000 kernel weights are recorded in Alberta’s Seed Guide.

Cracked pea seed coats reduce germination, so if an air seeder or air drill is used for seeding, care must be taken to reduce seed coat damage. Seed drill air velocity must be set as low as possible without plugging the hoses. In some cases, travel speed may have to be reduced to be able to adequately reduce airflow. If seeds continue to crack, one may wish to slightly raise the seeding rate.

“Seeding deep is better than seeding shallow,” recommends Whatley. “Pea seeds are large, so they should be seeded deeper into moist soil to be able to properly imbibe water from all sides. It is recommended to place pea seeds 1.5 inches into moist soil. With good moisture conditions, optimal seeding depth when direct seeding would be 1.5 to 2.0 inches, while seeding into pre-worked soil would be on the deeper side of this guideline.”

To prevent guard and sickle section breakage when harvesting, and to achieve faster harvesting speed, it is preferable to roll pea fields after seeding. Rolling pushes down stones and levels out dirt lumps and soil ridges, creating a smooth field surface. Rolling field pea can be carried out from immediately after seeding to the 5-leaf stage. To prevent seedling damage when carrying out post-emergent rolling, only roll on dry days to prevent disease transfer and leave a one- to two-day window between rolling and treating with a herbicide. It is also important to avoid rolling early in the morning to prevent pea stem breakage.

“For various reasons, growers are considering inclusion of field pea into their cropping rotations this year,” says Whatley. “Field pea is a good option and higher yields can be achieved by making some key decisions at seeding time.”