Research shows that it takes as little as one volunteer corn plant per fi ve feet of row to reduce
soybean yield. Volunteer corn plants rob moisture and nutrients needed to maximize yield. One
volunteer corn plant per square yard equals approximately a 4% yield loss, and dropped ears that
create clumps of volunteer corn can be considerably worse. A 4% loss on a 50 bushel per acre
soybean yield would be two bushels per acre. I know, that doesn’t sound like much, but consider
this, as I’m writing this soybeans on the Chicago Board of Trade are priced at $13.77/bu. Two
bushels per acre loss is a $27.54/acre loss. A 160 acre fi eld equates to a little over $4400!
Let’s say that Select Max costs $120 per gallon for illustration purposes. Six ounces per acre
would cost about $5.63 per acre. That alone justifi es the cost to control the volunteer corn. Plus,
if you use Roundup WeatherMAX, Monsanto will rebate back at least $2.60 per acre towards
the cost of the Select Max. That brings the cost of application down to $3.03 per acre. Here’s the
kicker, if you are using Harness as a pre-emerge herbicide on your corn acres, Monsanto will rebate an additional $1.30 per acre towards the SelectMax. That brings the net cost of the product
down to $1.73 per acre! $1.73 to protect $27.54! Not bad.
Here is a breakdown of the Roundup Rewards program for SelectMax to control volunteer corn:

2007 Research at South Dakota State University showed having as little as 1 volunteer corn plant
in 20 square feet in your fi eld can cause yield loss of over 15%. Other research has shown similar
results over the years. Why take the yield loss AND provide a host for more corn rootworms
when SelectMax could cost you less than $2 per acre net? I know it’s easy to focus on lambsquarters, waterhemp, or other broadleaves as the weeds you really want to target this year, but in our opinion, volunteer corn could be the worst yield-robber of all in your soybeans.