Aster yellows and healthy looking plants

Purpling caused by aster yellows disease in canola

Stress from aster yellows can lead to purpling, as shown in this plant. Late or mild aster yellows infections may produce purpling even without the typical misshapen pods.

Puffed bladder-like pods are an obvious sign of aster yellows, but  some plants with aster yellows can produce pods that look fairly normal but still have significant losses due to poor seed formation. Late or mild infections, for example, could lead to poor seed set in normal-looking pods. Stress from aster yellows can also sometimes lead to purpling or may aggravate sunscald.

Given the high level of aster yellows this year, many growers and agronomists have questions about the disease. We will look into these questions, and try to find answers to share during winter meetings. If you have questions about aster yellows, please email them to Jay Whetter at or send by Twitter to @CanolaWatch.