How do I know when it is time to swath my canola?

First of all, walk or drive around the perimeter of the field to assess for uniformity – no flowers should be seen and plants should not look grass green. Drive around again, stop and go into the crop at numerous points and pull pods from the bottom of the main stem, the middle and the top, as well as pods from secondary stems.  The seeds in the pod on the bottom of the plant should be firm with some black seeds and most seeds with a spot of black or tan color. Seeds in the middle pods should be firm with most seeds also showing a spot of color change.  In the top pods, seeds should be firm and not able to be squished between fingers.  The odd seed may have a spot of color change.  Seeds from pods on side stem should also be firm and have seeds with some color change. If the crop is ripening too fast or the edges are ripe and the middle green, swath the area that is ripe, potentially in the early morning when there is still dew on the pods, as this will reduce the amount of shelling out.

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My flax did not flower and looks like the growing point is dead, could it be herbicide injury?

It very well could be herbicide injury or potentially environmental stress damage.  Applying herbicides especially those with a broadleaf control component under very hot and humid conditions can damage flax.  The growing point may be damaged even more if spraying occurred after flax is 6 inches or taller.  Spraying flax when the temperature has not exceeded or is not going to exceed 28C within a 48 hour timeline around the herbicide application will help reduce the injury to flax.  Also, only spraying products that are registered on flax will help reduce injury as they have been tested and approved to provide acceptable weed control without causing unacceptable crop injury.

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I think I have aster yellows in my flax, can I spray anything to stop it from getting worse?

If you are already seeing symptoms of aster yellows in flax, it is too late for any control. The infection would have occurred from aster leaf hoppers that blew in from the south and were feeding 3 or more weeks ago. There are no fungicides available to control aster yellows. In field crops, insecticides are generally considered of little value in management of this disease, as research shows a single insecticide application would have a low probability of being of much value, and multiple applications (as done in horticultural crops) would not be practical in field crops. Because damage is so visible, it is very easy to overestimate the amount of damage across a field, so assess the crop carefully before making conclusions.

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My canola has a number of dead plants in it. It has been a dry summer here, could I have sclerotinia?

Based on the rainfall in most of the province, the prematurely ripened plants are probably not due to sclerotinia, but there is a chance it could be.  Typically sclerotinia will look like prematurely ripened plants that are dead above a specific infection point on the stem.  Plant material tends to start shredding and may looked bleached.  More likely in 2012, it could be caused by blackleg which also causes premature ripening, but tends to affect the entire plant.  The stem may have lesions, but it will not shred and probably has black dots that look like pepper spots in the lesion.  To confirm diagnosis a sample can be sent to the MAFRI Crop Diagnostic lab in Winnipeg (submit sample through local MAFRI GO office).

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Why would my canola pods be splitting? I don’t see any insects that would cause the damage.

From what MAFRI staff has seen in the field and at the Crop Diagnostic Lab, we think that the cause may be due to aster yellows.  Look for any symptoms of aster yellows on the plant like bladder looking pods, purpling pigmentation and as the crop matures, these plants do not mature as quickly.  Aster yellows can cause seed abnormalities in late affected plants that display no other symptoms of the disease.  If in doubt, collect a sample, take some pictures and send it to MAFRI or submit a sample to be analyzed at the Crop Diagnostic lab in Winnipeg (can submit samples through local MAFRI GO office).

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