Early during the 2016 growing season, iron deficiency chlorosis in soybean was observed in many fields in the eastern part of North Dakota and northwest Minnesota, says Hans Kandel, North Dakota State University Extension agronomist.

Chlorosis symptoms occur if the plant is unable to take up enough iron (Fe), even if there is sufficient Fe in the soil. The symptoms, yellowing of the leaf tissue, with green veins, might be present during the two- to seven-trifoliolate-leaf stages.

NO IRON: Soybeans turn yellow early in the season in part of a field where they can’t take up enough iron. (Photo: NDSU)

Plants may grow out of IDC and will turn green at the end of the vegetative and reproductive growth stages. Yellowing and stunting of the plants during the early vegetative stages may reduce soybean yield. There are genetic differences among soybean varieties for tolerance to IDC. On soybean ground with high pH soils and free bicarbonate and with known chlorosis problems, variety selection is the best way to achieve high yield on areas of the field that have IDC.

For soybean varieties tested by NDSU in 2016, the Roundup Ready IDC and Conventional/LibertyLink IDC scores are available at the NDSU website.

Source: NDSU