Corn Nematodes

      We are seeing some nematode affects on corn again this year. I haven’t seen as many cases as last year when the corn growth was slow and it rained more earlier but we still have nematode problems this year too. The site below had Stubby-Root nematodes that showed up in the soil sample. They usually occur in areas of the field. This field had corn in it last year so a low population may have increased due to the lack of rotation and a nematicide was not used this year.

Here’s a link to a UGA Page concerning these pests and an excerpt below.

“The stubby-root nematode life cycle is simple, going from egg through four molts to adult without changes in body form except that adults are larger than larvae. The life cycle is relatively short, reportedly ranging from 16 to 17 days at 86 F and from 20 to 22 days at 71.6 F. Populations may increase tenfold in 60 days. The population thus builds up rapidly even in the cooler spring months, making it a serious problem on early-planted, susceptible crops such as corn. The population density may also decline very rapidly. This can make diagnosis rather difficult since peak populations may be missed. “

“Stubby-root nematodes, Paratrichodorus (or Trichodorus) spp. are widespread in Georgia. Stubby-root is the most damaging nematode of corn because corn is highly susceptible and these nematodes are so widely distributed in coastal plains soils where much of the corn is grown.

These nematodes feed mostly at root tips, thereby stopping root growth. As new root growthcontinues to be stopped by feeding of stubby-root nematodes, the root system takes on a characteristic “stubby-root” appearance. Affected root tips may be “stubbed” without discoloration or a slight discoloration may be evident.”

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