Pea aphids populations have been reaching problematic levels in some parts of the Prairies over the last few weeks.
In this Pulse School episode, Dennis Lange, provincial pulse specialist in Manitoba, says they’re still a concern in some areas.
“We’re at the stage where some of the later seeded pea fields are in the late flowering stage, pods are just starting to form, and at that stage, they’re reaching threshold levels of anywhere from 90 to 120 aphids in 10 sweeps,” he explains.
Manitoba Agriculture’s recommended threshold for pea aphid control, which Lange alludes to, is reached when you find 90 to 120 aphids in 10 sweeps. Saskatchewan’s Ministry of Agriculture says pea aphids reach economic levels in peas when you find 2-3 aphids in the top 20cm of the plant. Sask Ag also refers to there being more than 10 aphids per plant during the period between formation of the 10th node and the appearance of the first flower.
The decision should take into account the impact of beneficial insects keeping aphid populations down, notes Lange. Heavy rain or wind — which there’s been plenty of in Western Canada this summer — will also knock pea aphids off the canopy.
Crop staging is another important factor, stresses Lange.
“Once you get the seed forming and have nice seed formation in the pod, then you’re past the area where damage from aphids will come into play,” he says.
Check out the video above, filmed at the Crop Diagnostic School in Carman, Man., for more on pea aphid scouting and control.