I have had numerous calls about corn looking ugly and stunted in areas of the field.
In many cases the culprit was nematodes and the corn has been slow to grow out of it. The unusually warm winter and spring has enabled nematodes to get started earlier and higher populations have damaged corn.
Most of the corn has grown out of the nematode damage, but there will probably be some yield reductions associated with the early nematode damage.
We are probably going to see more pressure in cotton with southern root-knot (Meloidogyne incognita) nematodes.
We are fortunate as I have not documented peanut root-knot (Meloidogyne arenaria) nematodes in Coffee County. Peanuts are not a host for southern root-knot nematodes and cotton is a non-host to peanut root-knot nematodes.
Corn is a host for both, but past experience with both root-knot nematodes as county agent in Decatur County in the southwest corner of the state indicates that southern root-knot nematode populations build up and sustain higher levels in corn than peanut root-knot nematodes.
Cotton planted behind corn may be susceptible to these high southern root-knot populations.
Many farmers may be familiar with the galling associated with root-knot nematodes, but other species of nematodes that attack corn, such as stubby root and sting, may not produce any galling. Corn is also a host for Columbia lance.
Field corn is not a host for reniform nematode that also causes damage in cotton.
Once corn is planted and nematodes are a problem, keep the corn from stressing. Irrigation or timely rainfall is critical in these fields.
Chemical nematode control options need to be made before corn is planted. Products currently labeled for management of nematodes affecting corn include:
Telone II(3 gallons per acre) Excellent control.
Counter 20G (highest labeled rate is 6.5 pounds per acre) Fair-to-good control. (There may still be some Counter 15G on-farm and its rate is 7 pounds per acre)
AVICTA Complete Corn(seed treatment) still being evaluated; has provided fair-to-good control in some trials.
PONCHO VOTiVO(seed treatment) still under evaluation
A word to the wise. A good management tool would be to take nematode samples later in the year (June-early July) to determine which species of nematodes are present and at what populations so you can make good decisions on nematode control in future crops.
See more at http://on-the-farm.com/2012/05/01/nematodes-jumping-on-corn/ .