Four weeks in swath? Be patient

2010 – Issue 21

Harvest

With crop that’s been in the swath for 3, 4 or 5 weeks and is not drying down, growers are probably best to be patient and wait for better harvest conditions. It is still September and the risk of having to leave the crop to overwinter in the swath is still reasonably low. In most cases, canola quality will not deteriorate and with a couple warm days dry down should advance quickly.

Issues are showing up in some of these fields.
Alternaria and moulds are turning swaths black. These fungi should have little effect on the quality of seed that has been in the swath for weeks, but they may present combining challenges. Pods could be more predisposed to shattering during harvesting. Set the combine pickup at the appropriate height and match the pickup speed to ground speed to minimize losses.
Seeds are sprouting in the pods in some locales. The photos below are from a field near Tisdale, Saskatchewan. Growers can do little to prevent this, other than ensuring they are prepared to combine as soon as the crop is ready.

Should growers combine canola ahead of cereals? Normally, in a wet fall growers would want to get their cereals off first since they’re much more susceptible to grade loss and sprouting. But in some areas, wheat and barley have already lost a few grades from sprouting and weathering. If that is the case and good quality canola is starting to show signs of weathering or some of the issues mentioned above, it may be wise to combine the canola first if it’s ready. Ensure the crop is binned safely. Aeration alone, especially with cool and damp outside air, won’t remove much or any moisture. Consider having a dryer ready, but keep in mind that safe drying temperatures for canola can be much lower than for other crops.

More on sprouting. There are two types of sprouting:
—The natural cycle. If canola matures and dries down naturally but conditions turn wet and harvest is delayed, canola seeds can take on moisture and start to sprout. Hormones within the seed may trigger germination — sprouting — if wet conditions increase seed moisture sufficiently.
—Precocious sprouting. Drought conditions, as experienced in the Peace this year, can upset the hormone balance. Hormones that normally prevent sprouting of immature crop are not functioning. Sprouting can occur before the crop reaches physiological maturity.
In both cases, there is nothing growers can do to prevent it.

Canola Watch