The following information is a Web Extra from the pages of Farm Journal. It corresponds with the article "Watch out for Corn Nematodes." You can find the article in Farm Journal's January 2012 issue.
New Iowa Nematode Report
A brand-new article in the online journal Plant Health Progress summarizes the results of testing for nematodes that feed in corn in Iowa from 2000 through 2010. Among the findings:
One or more species of nematodes that feed on corn were found in 92% of the samples.
The nematodes most frequently found were spiral (in 77% of samples) and root-lesion nematodes (in 51% of samples).
Overall, 15% of the samples contained nematodes present in numbers exceeding the damage threshold.
No sample had more than one nematode species present at damaging levels.
The nematode most commonly found at damaging levels was the needle nematode (in 8% of the samples).
The nematode most frequently present at damaging population densities was the dagger nematode (in 6% of the samples).
Although spiral nematode was found in 77% of the samples, only 1% contained numbers exceeding the damage threshold.
For a previous Farm Journal story, which includes information about how to sample soil for corn nematodes, read Whip Corn Nematodes.