Sudden Death Syndrome Showing Up In Soybeans, But Numbers Overall Low In Eastern Ontario

This year’s weather has led to ideal conditions for sudden death syndrome (SDS) in soybeans, but Eastern Ontario farmers haven’t been as hard hit as their Western Ontario brethren.

The number of cases in Eastern Ontario is up this year, said independent agronomist Gilles Quesnel, but overall, the number of fields with the disease is still low for the plant disease that has been in the area for years.

The disease thrived in cool wet conditions dur­ing planting, followed by hot dry stress conditions and the frequent and con­sistent rains from mid-July until early September.

SDS is a root rot disease where symptoms do not show up until the mid-pod reproductive stage, and by then, it is too late to do anything. The first symptom is a distinct yel­low speckling or spotting between the veins on the leaves. Eventually, the parts of the leaf between the veins turn brown and fall out. The next symptom is plant death.

Yield losses are varied, depending on the severity of the disease.

Quesnel said once a field has the disease, it increases the chances the field will get SDS again in the future with the right conditions. He added root diseases in soybeans are usually a problem on heavier soils such as clay, but he said to date, SDS has been more prominent on the lighter soils.