Pink bacterium saves soybean pods

May 12, 2003 12:00 PM, Wayne Wenzel

Pink Methylobacterium could be the next big yield enhancer for soybeans. The news first broke in 2000 after Salisbury State University researcher Mark Holland documented that a spray mixture of pink bacterium significantly enhanced soybean yield at research stations in Maryland.

Since then, Holland has shipped cultures of the naturally occuring microrganism to researchers in other parts of the country. Results continue to be promising, with the latest thumbs-up coming from Mark Dittrich and research sponsored by the American Farm Bureau Foundation at the University of St. Peter in Minnesota. In Dittrich's research, pink bacterium was sprayed on drought-stressed soybeans ranging in growth stage from R-2 to R-5. At harvest, treated beans had more viable pods, higher yields and less shattering.

Similar research conducted by Arise Research and Discovery at plots near Martinsville, IL, showed yield response under drought stress conditions as well, translating into 3.5 more pushels per acre.

Researchers think that adding the bacterium increases soybean yield by preventing pods from aborting. It doesn’t produce any more pods or increase the size of the seeds; it simply helps the plant keep more of the pods that it normally produces. The current thinking is that the soybean plant normally produces methanol as toxic waste. The pink bacterium likes to eat the methanol and use the carbon for energy. The bacterium then produces cytokinins, which are plant growth regulators that somehow stimulate the plant to keep its pods even under hot, dry stressful conditions.