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