Sample For Nematodes 50 Days After Planting
BETTY VALLE GEGG-NAEGER
MidAmerica Farmer Grower
DIXON SPRINGS, ILL.
Corn nematodes were the topic of an address by Dr. Angie Peltier, commercial agriculture extension educator from the University of Illinois, recently.
“Corn nematodes are very widespread throughout the state,” she said. “They are small unsegmented roundworms that feed on corn roots. There is a common misconception that nematodes only occur in very sandy soils, this is not the case.”
Nematodes occur throughout most of the soils in the state of Illinois. The reason people might associate nematodes with sandy soils is because sandy soils are less forgiving when it comes to root damage, so especially in hot, dry weather the damage that’s caused by corn nematode feeding is very dramatic, especially if there are very high populations.
“Some yield loss is associated with very high populations of corn nematodes,” Peltier said. “What I would suggest is that folks, if they’re interested in learning how many corn nematodes are in their field, should collect a sample. What we’re looking for is a soil sample with some roots in that sample. Send it to the Illinois Plant Clinic or to some other laboratory that has a nematologist. Unfortunately we’ve already missed the window for the ideal time to sample for corn nematode.”
Dr. Angie Peltier, commercial agriculture extension educator from the University of Illinois, recently
discussed corn nematodes, a small unsegmented roundworm that feeds on corn roots.
Photo by John LaRose, Jr.
Nematode sampling usually should be done about 50 to 60 days after planting. So farmers should consider sampling for nematodes next planting season. The last several years seed companies and chemical companies have released two different corn nematode seed treatments. There’s also an in-furrow treatment for corn nematodes. Much research has been done since then by the many nematologists and plant pathologists throughout the region, and results have varied quite a bit.
Many of the field trials have been conducted in fields that have typical levels of corn nematodes and so the population levels might not be very high. Others have been conducted in fields that have very high populations of corn feeding nematodes.
“The results have varied quite a bit, so what we recommend is that individuals consider sampling to see whether they have a high population of corn nematodes in their fields and whether seed treatment or some other treatment might be necessary,” she summed. ∆
BETTY VALLE GEGG-NAEGER: Senior Staff Writer, MidAmerica Farmer Grower