The term corn nematodes would imply that these pests are one uniform group and that they only feed on corn, but this is not correct. There are more than a dozen different species of plant-parasitic nematodes that feed on corn. Most of these also have a wide range of hosts.
Nematodes that feed on corn are not new to the Midwest, these nematodes are believed to have been present since long before corn was a crop in this region. Before corn was a major crop, these pests fed and lived on native plants and prairie grasses
It is common to find these nematodes that feed on corn in almost every field in the Midwest, but populations must reach a certain number called the damage threshold before they are believed to reduce corn yields. This damage threshold varies between species also, for example it only takes 1 sting nematode per 100 cm3 while it would take over 1,000 spiral cause significant damage.
There have been many changes in crop production practices that have been blamed for the increase in nematode damage to corn. These include decrease in soil-applied insecticides, corn frequent cropping of corn, and a decrease in the amount of tillage performed on each acre. While there is no way of knowing that these factors are the cause, we have seen an increase in damage to corn from these pests.
The only way to determine if plant-parasitic nematodes are causing yield loss in your field is to take soil and root sample and have them tested by a qualified lab.
Nothing can be done to minimize the damage or “rescue” a corn crop if nematode damage is confirmed during the growing season. But there are some good management strategies to protect corn from nematode damage in future years. One of these strategies is to use a seed treatment such as Votivo on the seed before planting. Votivo is a very promising new seed treatment that is showing great performance in the Midwest. Please contact you local Trelay DSM for more info on nematodes that feed on corn and what control options are available for your farm.
