Soybean seed deterioration seen in Missouri

The 2024 soybean growing season finished with significant quality issues in southeast Missouri.

Farmers are being heavily docked at the elevator, further aggravating the already low commodity prices. Problems began after Hurricane Helene brought heavy rainfall to the region in late September, exposing mature beans to excessive moisture.

Even before Hurricane Helene struck, low test weights were anticipated due to the drought during soybean seed filling, as predicted by the University of Missouri’s Soybean Growth and Yield tool. However, seed deterioration and other quality issues only became apparent after the storm.

Farmers initially observed seed sprouting in the pods as the first sign of damage. As moisture receded, small, deformed seeds with brown to greyish discoloration were left behind.

While shattering is common, the damage extends beyond open pods. Farmers also report easily peeled seed hulls and cracks in pod walls. Additionally, plants retained green stems and leaves long after pods reached harvest maturity.

Multiple observations and reports suggest the issue appeared indiscriminate of cultivar, maturity group or seed brands.

Mature seeds exposed to standing water absorbed moisture and swelled. Since the seeds were undersized due to drought conditions, this swelling likely caused the hulls to rupture. Once damaged, the seeds became more vulnerable to rapid cycles of wetting and drying, leaving the cotyledons exposed to weather-related deterioration and opportunistic microorganisms.

Soybean seeds had symptoms and signs of purple seed stain, Diaporthe seed decay and dehydration along with additional symptoms. Further testing of the seed concluded that Fusarium, Cercospora and Diaporthe species were present in damaged seed samples.