Including canola more than once in a four-year rotation is not recommended, even if farmers plant clubroot-resistant canola, says Murray Hartman, oilseed specialist with Alberta Agriculture and Rural Development.
Earlier this year resistant variety 45H29 was registered on a three-year, interim basis. “There was a limited amount of seed available this year, but next year there should be a good supply of commercial seed for farmers,” Hartman says.
Crop specialists stress, however, that even if using clubroot-resistant canola seed farmers should still not tighten up the rotation more than the recommended once every four years.
“The reason for a one-in-four rotation for canola is to slow down the breakdown of resistance, which has happened in other parts of the world. Then, we once again would face a clubroot problem in the province,” says Hartman. “If farmers start planting canola on fields sooner than the recommended rotation, we can expect that the resistant varieties will quickly lose their resistance.”
There hasn’t been a lot of clubroot reported this year. The dry weather experienced in spring and early summer hindered clubroot, especially during the month of May when the infection usually starts.