Manitoba's soybean growers are once again dealing with iron deficiency chlorosis (IDC).

Manitoba Pulse and Soybean Growers Production Specialist Serena Klippenstein says IDC is widespread this year and is increased from what growers experienced in 2018. Cases of IDC were also high back in 2017.

She notes IDC shows up as yellowing of new soybean leaves, usually at the V1 stage. IDC is caused by a reduced uptake of iron by the plant after the iron source in the seed is depleted. Risk factors that lead to IDC include high levels of calcium carbonate, soluble salt, and moisture or nitrate in the soil.

"Though in-season rescue options are limited, waiting until the plants recover on their own is the most common solution," explained Klippenstein. "Luckily yield loss will be minimal if soybeans recover from IDC by the fifth to sixth trifoliate stage."