WithTheGrain: Canola disease management decisions fuelled by economic goals

Author: | Date: 16 Apr 2018

Image of Brett Gilbertson
Millicent, SA, grower Brett Gilbertson manages canola diseases sclerotinia and blackleg with fungicides and is keen for more research to perfect canola cropping restraint management.

Millicent grower Brett Gilbertson is mindful of the economic effects of canola disease management when he makes decisions to spray fungicides.

The high-rainfall zone (HRZ) Regional Cropping Solutions Network (RCSN) member says GRDC investments are helping to fill the knowledge gap to ensure canola cropping restraints can be addressed with proven responses.

Sclerotinia and blackleg are diseases that Brett manages on his property using fungicides, but also by selecting varieties for their flowering windows and genetic resistance.

“We manage blackleg through variety selection,” he says.

“We grow varieties with good genetic resistance, we consider both single and double gene resistance.”

In 2018, Brett will be growing Clearfield® 45Y91 and Banker canola varieties as precautionary blackleg control measures. He says he is doing so to ensure the longevity of his crop rotations despite not seeing any blackleg in his crops last season.

“A lot of people are growing canola in this area and the old rule of not growing the same crop within 500 metres of where you did last year can’t apply in this intensive cropping environment,” he says.

Brett says he has not seen sclerotinia on his property in recent years but is ‘aware and looking out for it’.

He is aware it could become a real issue very quickly in their operation if regular monitoring wasn’t conducted.

“Variety management choices are common practices we keep an eye on, but as far as an in-crop spray we don’t routinely blanket spray fungicides, but when we do we are looking for a yield response,” Brett says.

“Instead we do it in some paddocks and we’re looking for a yield response when we do.”

Powdery mildew is an ongoing concern for Brett, who has observed the issue in recent seasons.

However, without an appropriate fungicide on the market to address the problem, he says there is little he can do to address the disease besides cultural practices such as crop rotation and cruciferous weed control.

“In regard to the management of cereal diseases, we have a real definite timing of treatment and results out there to back that up, we have management packages for different cereals relatively down pat,” he says.

“At the moment there’s nothing like that for powdery mildew in canola and in my case, we know we have powdery mildew issues, but there is currently no science around the application of fungicide to manage powdery mildew.”

More information

Brett Gilbertson,
brettmel@gilbrae.com.au