Pea aphids love to feed off the sap flowing to new pods on the plant. The trouble is, just two aphids per plant at the right stage can siphon off as much as five per cent of yield.
Laura Schmidt, production specialist with the Manitoba Pulse and Soybean Growers, says that modern pea varieties are somewhat more tolerant to aphid feeding than varieties from days gone by, but the overall yield potential of the crop (and value!) should go in to making the decision on whether or not a control spray is warranted.
In this episode of the Pulse School, Schmidt recommends a minimum of two field visits when gauging pest pressure. That’s because aphids are a favourite meal of ladybug larvae, lacewings, and a few parasitoids, and these beneficial insects can do an excellent job of keeping pest levels in check.
Schmidt suggests to scout once just ahead of that flat pod (R3) stage to assess aphid levels, and then again to re-assess the direction of population: is it building? If not, those beneficials are doing the work for you.
She adds that late planted fields may be at higher risk of aphid feeding, but may also not have the yield potential that warrants a spray application.
Looking for more episodes of the Pulse School? Find them all here!