To reseed canola – or not
June 6, 2016 - This is the time of year when canola producers are evaluating their crop to decide whether or not to reseed.
"Before the recent rains came, we did have some poor looking canola crops," says Murray Hartman, provincial oilseed specialist, Alberta Agriculture and Forestry. "The dry conditions in April and early May resulted in poor germination and low stand densities."
In some cases, seeding was done deep to moisture which resulted in thin stands when the seedlings didn't have enough energy to get out of the ground or got infected by seedling blights. In others, seeding was done shallow and the seedlings ended up stranded in the dry soil. Both cases looked poor until the rain came. "In addition, we had some stand thinning on the plants that did emerge due to frosts, flea beetle pressure and cutworms."
Now that the rain has come Hartman says many stands will recover. "Any of the seeds that were stranded in dry soil should have now germinated and emerged. These stands should fill in and be fine."
However, Hartman says if the thin stands were a result of deep seeding, or due to frost or insects, they are probably going to stay thin. "If the seeds died, there is nothing to come out even after the rain. These are the fields that really need to be checked, either to ensure there is adequate density or to reseed."
He says that, at this time of year one, to two plants per square foot is acceptable, as compared to similar or even lowered yields that will usually result from late seeding.
If reseeding is required, it should be done by June 10-14. "Typically, we've probably already lost 25 per cent of the yield potential by the start of June. By waiting until the middle of June, it goes down more and brings a higher risk of poor quality from fall frost."
He says there are also other options to just reseeding canola. "The dry conditions have also impacted forage resources. If you have a mixed operation with cattle, or your neighbours do, and there is a need for pasture or greenfeed, going with that may be a better option than just trying to reseed canola."
Bottom line, says Hartman, is to get out there and see what you have. "Don't just assume that if was bad two weeks ago, it will still be bad. If it was seeded in dry soil, it may be fine. But if was seeded deep, or affected by frost or insects, you had better judge the numbers carefully."
June 6, 2016 By Alberta Agriculture and Forestry