Agronomic Services — News Release
FOR IMMEDIATE RELEASE
THURSDAY, JUNE 27, 2002
Contact: Rick Morris
Soybean cyst nematodes and drought
—a bad combination for soybeans
by Rick Morris, NCDA&CS regional agronomist for Bladen, Brunswick, Columbus, Cumberland and Robeson counties
BLADENBORO — Extreme drought conditions over much of the state has put most field crops under considerable stress, which have made them more susceptible to pests and diseases. In some cases this combination of conditions has proven deadly to plants. I have recently received calls from soybean growers in southeastern North Carolina who have experienced problems with dying plants.
Seedling diseases, grass and weed competition, excessive heat, and nematodes all limit a crop’s ability to uptake and transfer water and nutrients. This combination of stress factors can be enough to kill weak soybean plants.
In working with farmers on this situation, I often found high populations of cyst nematodes. Nematodes attack the root systems of soybeans, reducing the crops’ ability to absorb water and nutrients.
Growers who have experienced similar problems may want to sample their fields for nematodes. It may be too late to correct the problem this growing season, but steps can be taken to correct the problem for future crops.
Crop rotation, variety election and crop protection chemicals can be effective tools for managing nematodes. Crop rotation is one tool that is often ignored. When the same crop is grown continuously in a field over several growing seasons, nematode populations increase to damaging levels.
When fields have not been rotated, planting resistant varieties will not automatically correct a nematode problem. Overdependence on resistant varieties leads to race shifts within nematode populations. As a result, resistant varieties may be less effective and management more difficult.
When soybeans are under stress, it is important to correct weed problems as soon as possible. Weeds are more difficult to kill during a drought, and as long as they remain, they will rob the crop of moisture.
If you find areas in your fields where soybeans have died, onsider the stress factors mentioned here. If you suspect a nematode problem on your farm or need assistance identifying the problem, contact your local agricultural advisor or call the NCDA&CS Agronomic Division at (919) 733-2655. Growers in Bladen, Brunswick, Columbus, Cumberland or Robeson counties, can call me, Rick Morris, at (910) 866-5485.
August 1, 2007