I’ve received lots of inquiries in the past few weeks about sampling fields for nematodes that feed on corn. Most every Iowa field has one or more different nematode species present at low numbers. But it’s only when numbers are at damaging levels that yield loss will occur.
Determining whether plant-parasitic nematodes are present in high enough numbers to cause damage and yield loss to corn is difficult. Multiple nematode species are usually present in a field, and the number of nematodes necessary to cause damage can vary from field to field. A new approach has been developed to assess the overall likelihood of damage occurring based on the nematode species and numbers present and the conditions of the field. This article explains the basics of the new system.
Symptoms of injury to corn from feeding by plant-parasitic nematodes includes yellow leaves, stunting of plants, and mid-day wilting. To determine if nematode feeding is responsible for crop injury symptoms observed in the field, soil and root samples must be collected and sent to a qualified laboratory for testing.
