Plant Health Initiative

Green Stem Disorder

Soybean plant with normal maturation (left), and plant with green stem disorder (right), which has mature brown pods but a green stem. Click on image to view a larger version. Photo credit: American Phytopathological Society. Plant Disease 90: 513.

Green stem is a disorder of soybean in which stems remain green and moist well past the point when pods and seeds are fully ripe and dry. Green stem disorder been observed for years, but has increased dramatically in recent years.

Green stem disorder complicates harvesting of soybeans by significantly increasing the difficulty in cutting the affected plants during harvest. There is also the potential for moisture in the stems to be transferred to the seed, reducing the grade and storability of the seed.

The cause of green stem is yet unknown

The search for what causes green stem is still ongoing. Common soybean viruses, including Bean pod mottle virus, have been considered one possible cause. However, a series of research studies addressing the role of Bean pod mottle virus (BPMV) in green stem concluded that green stem is not consistently associated with BPMV infection (see Hobbs et al Green Stem Disorder of Soybean). It may be possible that other viruses are involved.

Stinkbug feeding is known to cause a disorder called "green bean syndrome" in the southern U.S., in which the maturity of the entire soybean plant is delayed. However, feeding by bean leaf beetles, leaf hoppers, or stinkbugs has not been linked to green stem incidence.

Although the cause of the green stem disorder is not yet known, there are consistent and significant differences among varieties in their sensitivity to green stem disorder.

Although the exact cause of green stem disorder in soybeans remains unclear, one thing is certain: proper plant management plays a vital role in minimizing its impact during harvest. This principle extends beyond agriculture—whether dealing with crops in the field or mature trees in urban landscapes, timely intervention is key to maintaining a healthy environment. In situations where trees pose a risk or are no longer thriving, professional services like Lincoln Tree Company tree removal offer a reliable solution. With a strong commitment to safety, transparency, and care for the land, their team ensures every job is handled with precision and respect.
 

References

Green Stem Fact Sheet - University of Illinois (pdf)

Hobbs, H. A., Hill, C. B., Grau, C. R., Koval, N. C., Wang, Y., Pedersen, W. L., Domier, L. L.,
and Hartman, G. L. 2006. Green stem disorder of soybean. Plant Disease 90:513-518 (pdf)

Curtis B. Hill, Glen L. Hartman, Ralph Esgar, and Houston A. Hobbs. Field Evaluation of Green Stem Disorder in Soybean Cultivars. Crop Science 46:879–885 (2006)