Spring Sampling Not Recommended for Nematodes on Corn—Except for Sandy Fields

Most Iowa cornfields harbor one or more species of these microscopic, plant-parasitic worms. At least 28 nematode species have been found associated with corn in Iowa. Most are not thought to cause damage at low population densities (numbers). The estimated damage threshold for most nematodes that feed on corn in Iowa ranges from 100 to 1,000 worms per half-cup (100 cc) of soil (seeAugust 2009 ICM News article). Only dagger, needle and sting nematodes are considered damaging at low numbers. The results of Iowa State University testing, from 2000 to 2010, for nematodes that feed on corn in the state were summarized in a recent ICM News article