By Tom Collins
This year’s weather has led to ideal conditions for sudden death syndrome (SDS) in soybeans, said OMAFRA’s field crops pathologist.
The number and severity of cases this year are up significantly, said pathologist Albert Tenuta, thanks to cool wet conditions during planting, followed by hot dry stress conditions and the frequent and consistent rains from mid-July until early September.
Tenuta said SDS has been reported in Essex, Lambton, Elgin and Middlesex counties, and also in areas that have never had SDS in the past, such as in Eastern and Central Ontario. In 2015, 2.22 million bushels of Ontario soybeans were lost to SDS, and this year is expected to be much higher.
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.
Cool and wet conditions during planting and wetter conditions during the growing season are ideal for SDS. Yield losses are varied, depending on the severity of the disease.
OMAFRA’s soybean specialist Horst Bohner said farmers shouldn’t necessarily be worried if they have SDS.
“It’s like any of the diseases,” he said. “It’s all a question of severity and incidence. A little bit of sudden death doesn’t scare me at all. A plant here or there or a pocket here or there. That’s just par for the game. It’s when you get these fields that are heavily excessive, that’s when you start to get into trouble.”