Fields taken out of pasture or hayland last year and planned for canola this year could have high wireworm and cutworm populations. Wireworms can wipe out a whole field of canola and no seed treatment or spray is registered for wireworm control in canola.
Growers will want to get down with a trowel and sifter and look for wireworms in these fields before making the final decision to seed canola. Bait balls are unlikely to work to scout for wireworms in these fields given the high volume of decomposing plant material. Note that cutworm numbers also tend to be high in pasture and hayland, but cutworms can be managed with surface applied insecticide.
Other issues with canola seeded into broken pasture or hayland:
- If large chunks of sod are still present in the field, this can impede good seed to soil contact — which is important for canola seed survival and emergence.
- Pasture and hayland can be very nutrient deficient. Soil test to determine residual nutrient levels.
- Subsoil moisture tends to be lower, especially following a normal to dry year.
In general, growers should lower their yield expectations for canola seeded into fields taken out of pasture and hayland. They should also evaluate each field to determine if canola is really the best crop choice. Click here for more tips on sod seeding.