The Importance of Nematode Management in Corn and Soybean

Nematode damage is frequently underestimated and misattributed to stresses associated with drought, fertility, chemical injury, and disease; many farmers do not know that they have nematodes in their fields.

It has been estimated through sampling that over 80% of U.S. corn acres are infested with at least one species of nematode.1 Nematodes damage crops by feeding on the root system, which reduces the plant’s ability to take up water and nutrients. Nematode feeding also creates wounds that can serve as entry points for pathogens. Visual symptoms of a nematode infestation may not be visible for a number of years, but yield loss may still be occurring. When above-ground symptoms (such as wilting, yellowing, or stunting) do appear, it often indicates a long-term problem that is just being recognized.


Figure 1. Damage to soybean from root knot nematode. Photos courtesy of Edward Sikora, Auburn University,

When the plant is under stress from nematode feeding, other stresses become amplified. “Nematodes can make everything else worse,” says Clemson University plant pathologist John Mueller. “A corn root system infected with nematodes can exhibit additional moisture stress, reduced nutrient uptake, and lost yield potential. Without effective management, nematode numbers can increase year-to-year, reducing the yield potential of the current corn crop as well as other crops in the rotation.”2

In order to diagnose a nematode problem in your fields, it is necessary to collect soil and possibly also root samples and submit them to a laboratory for analysis. Contact your local plant diagnostic laboratory to confirm that they conduct nematode analyses and for specific instructions on sample Crop protection is accomplished through crop rotation, use of resistant soybean products, and available nematicides. In addition, NemaStrike™ Technology is a seed treatment product that provides broad-spectrum control of plant parasitic nematodes including all races of soybean cyst nematode, lesion, root knot, lance, reniform, sting, and needle. It is available in corn, soybeans, and cotton. With a novel mode of action and low water solubility, NemaStrike™ Technology (tioxazafen) is a synthetic nematicide that defends crops from the start and stays in the root zone as plants grow for up to 75 days. In numerous field trials over 4 years, the technology has helped to protect the average yields of soybean by 2.2 bu/acre (138 trials) and corn by 6 bu/acre (140 trials).3 Performance results will vary based on nematode pressure and crop genetics.

Sources: 1 AgriThority. 2016 nematode sampling study conducted in the U.S. Corn Belt. 2 J.H. Hudson, personal communication, May 13, 2013. 3 4-Year Average Yield Protection Advantage over control, across all locations and thresholds, N=341Trials (2014, 2015, 2016, 2017) (AR, GA, IA, IL, IN, KS, KY, LA, MD, MI, MN, MO, MS, NC, ND, NE, OH, SC, SD, TN, TX, VA, WI).  Monsanto Company. 180926135947