Illinois Fertilizer & Chemical Association
Supply · Service · Stewardship

Cupped Soybeans and Dicamba: Scientists Dispel Common Myths

Cupped soybean fields are surfacing across the South and Midwest again this summer, and with them, a new crop of rumored causes.
Once again, however, the simplest explanation for those puckered up soybeans remains off-target dicamba applications, agronomists and weed scientists told DTN. Tens of millions of acres of dicamba-tolerant soybeans are currently growing alongside non-dicamba-tolerant beans, and dicamba use in corn is on the rise in the fight against herbicide-tolerant weeds.
"I've heard about every possible alternative answer for cupped soybeans besides dicamba," said Iowa State University field agronomist Meaghan Anderson, with a touch of weariness. Theories thrown around Twitter and across fence lines this year point the finger at older products, such as AMS and Liberty, as well as newer alleged culprits, such as a genetic response of Enlist soybeans to stress or Enlist (2,4-D) herbicides.
"But a true cupping symptomology in soybeans is characteristic of a plant growth regulator and nothing else," Anderson said. While dicamba is the biggest culprit this year, other PGR products such as clopyralid are possibilities. Here, Ikley and Anderson explain how to distinguish between them, as well as dispel some common myths circulating this summer.
Click Here to read more.