A growing number of farmers are adopting a canola-wheat-canola-wheat rotation despite the increased risk of disease.

Profitability and ease of production are the two main reasons growers like to stick with canola.

But Dr. Neil Harker, a weed research scientist with Agriculture and Agri-Food Canada here in Lacombe says he's concerned about the long-term impact of the system.

Harker says from an agronomic point of view, adding winter cereals, pulses or a forage to the rotation would reduce the chances of developing herbicide resistant weeds.

However, those crops are not as profitable as canola.