Purdue signature

October 1, 2013

Green stem syndrome present in some Indiana soybean fields

WEST LAFAYETTE, Ind. – Some Indiana soybean fields are showing symptoms of green stem syndrome, a Purdue Extension soybean specialist says.

Green stem syndrome occurs when soybean pods and seeds mature - turning harvest color and drying out - while the stems remain green. Late-season stresses that interrupt seed-fill, such as weather, the environment, viral diseases or insect infestations, usually cause the problem.

"It's been noticed around the state, spots here and there where later-in-the-season weather stressed the plants," Shaun Casteel said. "The dry weather and heat caused plants to abort pods. The plants' demand for pod development and seed fill wasn't there anymore, so the plants started maintaining the stem as the plant matured."

Casteel said farmers should go into fields that seem to be browning and see if both the pods and stems are maturing.

"This year with some of those green stem-type fields, producers need to take a look at the pods themselves and the grain to see if they are dry enough for harvest," he said.

Soybeans should be harvested at or slightly above 13 percent moisture to maximize yield, but green stems are tough to harvest.

Casteel said producers with fields exhibiting green stem syndrome have two options.

The first is to harvest the beans at optimal grain moisture to capture water weight. Doing so likely will slow harvest and increase fuel costs because of the green stems.

"For harvest, be prepared to have to chew through fields with green-stem syndrome with the combine, especially with older equipment," Casteel said.

Another option is to wait and harvest the plants when the stems turn brown. This option is easier on equipment but likely will reduce yield due to lost water weight. Delaying harvest for a few weeks also could allow the pods more time to dry out and possibly shatter.

"Producers need to be aware that this phenomenon is occurring so they can make informed decisions about optimizing harvest and reducing losses in yield and profit," Casteel said. 

Writer: Amanda Gee, 765-494-8402, agee@purdue.edu 

Source: Shaun Casteel, 765-494-0895, scasteel@purdue.edu 

Ag Communications: (765) 494-2722;
Keith Robinson, robins89@purdue.edu
Agriculture News Page