DR. JUSTIN CALHOUN / MISSISSIPPI STATE, MISSISSIPPI
With all the other things going on during the 2025 soybean season, we also received a lot of calls and questions about iron deficiency chlorosis (IDC). If you’re not familiar, IDC occurs in Mississippi mainly in the Black Belt region where calcareous soils tend to have extremely high pH values. In these soils, iron (Fe) becomes unavailable for plant uptake, leading to characteristic yellowing (chlorosis) and stunted growth.
While IDC tends to follow the same soil textures and pH lines in the Black Belt, its severity can vary from year to year. Environmental conditions and plant stress ultimately determine how well a soybean responds to limited Fe availability. In 2025, much of the crop in that region was planted late, followed by extremely wet conditions and then a rapid shift to dry weather across large areas of non-irrigated ground—perfect conditions for IDC expression.
Because of this environmental variability, IDC ratings on variety spec sheets can sometimes be misleading. I received numerous calls this year about soybeans with IDC symptoms even though they were rated on their spec sheet as “3 or better” for IDC tolerance. Depending on the environment where those ratings were developed, the results may not fully represent conditions like those we experience in Mississippi.
For that reason, we strongly recommend consulting local IDC screening data through Mississippi State University Extension and local seed representatives to get a more accurate picture of how varieties perform in your area. Below are the results from our 2025 IDC Soybean Variety Screening conducted in Noxubee and Monroe Counties.
DR. JUSTIN CALHOUN / MISSISSIPPI STATE, MISSISSIPPI
Link To Original Article: https://www.mississippi-crops.com/2025/10/28/2025-soybean-variety-response-to-iron-deficiency-chlorosis/
The post 2025 Soybean Variety Response to Iron Deficiency Chlorosis appeared first on Soybean South.
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