A critical first step in managing tar spot is predicting the risk of it developing. Experts say growers should keep up to date on the presence of tar spot in their fields and in the general area.

Learning to live with tar spot

Know what decisions to make, and when to make them, are key to controlling the disease

Tar spot, the latest corn disease to cross the border, is in Ontario to stay.  Knowing when the risk of tar spot development is high, how to identify the pathogen, […] Read more


A new study argues that a co-ordinated global reporting mechanism could minimize the risk of spread of plant diseases such as Ug99, a rust that has devastated cereal crops around the world.

Researchers warn about plant pandemics

New report calls for more pathogen surveillance and monitoring systems and better strategies to address plant diseases

Glacier FarmMedia – The world is preoccupied with the COVID-19 pandemic, but plant pandemics are also a threat. Sixteen researchers published a paper in May urging action to prevent the […] Read more

Top: The fisheye lesion is one indication of tar spot. Bottom: Tar spot has expanded across the midwestern United States and now into Ontario.

Learning to scout corn for tar spot

U.S. weather could play a role in spread of new fungal infection

Corn technician Jonathan Brinkman noticed unusual symptoms on his field plot at the University of Guelph, Ridgetown campus last September.  Several crop leaves displayed a raised, black, tar spot type […] Read more


Sudden death syndrome is easy to identify as the leaves remain green around the main vein and major lateral veins.

High disease pressure, low impact

Late onset of soy sudden death syndrome should mean fewer yield challenges

Sudden death syndrome (SDS), a common disease found in soybeans, is showing up across the province but should be of limited yield impact this year due to its late onset. […] Read more