[University of Arkansas Division of Agriculture Research and Extension
University of Arkansas System. Arkansas Soybean Promotion Board. Dr. Bob Scott,
Extension Weed Specialist, Crop, Soil and Environmental Science, Lonoke Research
and Extension Center, University of Arkansas Division of Agriculture, Lonoke
Research and Extension Center]
I’m Bob Scott, extension weed specialist with the
University of Arkansas Cooperative Extension Service. [Bob Scott standing in a
soybean field holding a soybean plant.]
Sometimes in the fall, it becomes necessary to apply a
harvest aid to soybeans, either because of weed pressure, or because of the need
to defoliate soybeans, that for environmental reasons have retained too many
green leaves. [Video shows a soybean field with weeds.]
There are a few things that are important to remember about
harvest aid applications. First of all, you do not want to make a harvest aid
application too early. According to the label, most harvest aid applications
should go out after at least 50 percent of the green leaves have dropped from
the soybeans and at least 50 percent of the soybean pods have turned yellow.
This will ensure that the harvest aid is not applied too early. If a harvest aid
is applied too early, it can prevent the soybeans from properly maturing out.
[Slide: Important to remember - Be careful not to apply your harvest aid too
early; Harvest aid applications should go out after 50% of leaves have fallen.]
It’s also important to remember that a harvest aid does not
speed along the maturity of soybeans. It cannot also, in and of itself, help dry
out a soybean, although sometimes the removal of the extra green leaves and the
weedy materials present in the field will result in lowering the moisture and
speeding up harvest to some degree.
There are a limited number of products available of harvest
aids in soybeans. These include paraquat, sodium chlorate, Aim® and Sharpen®.
Aim® and Sharpen® are primarily recommended when weeds are present, such as
morning glories or hemp sesbania. And they are usually tank mixed with paraquat
or sodium chlorate. [Slide: Recommended Harvest Aides - Paraquat, sodium
chlorate, Aim®, Sharpen®.]
One of my favorite harvest aid applications is Gramoxone®
at two-thirds of a pint plus 3 pounds of sodium chlorate, applied to around 14
days prior to harvesting soybeans. [Slide: Recommended Harvest Aides - Gramoxone®
(two-thirds pint) plus sodium chlorate (three pounds) applied 14 days prior to
If you follow these guidelines and directions, harvest aid
applications can be made safely and can improve harvest efficiency and the speed
at which a field is harvested.
For more information, you can go to the web at
www.uaex.edu and search for the MP44 in the soybean section.
[www.uaex.edu. University of Arkansas Division of Agriculture Research and
Extension University of Arkansas System. Arkansas Soybean Promotion Board]