By Jeff Cook
4 years without Temik, poor crop rotation, ineffective seed treatments and expensive fumigants and we wonder why we have nematode problems. Nematodes are thread-like microscopic worms that live in all habitats especially soil and water. Most species are beneficial but some are harmful parasites of plants and animals. Plant parasitic nematodes have a needle-like stylet that allows them to feed on plant parts. Nematode not only cause direct impact from feeding damage, but may also serve as entry points for diseases causing increased economic losses.
We may be on the tail end of the recommended sampling window, but I say, “better late than never”. September to November are the recommended dates for sampling in most agronomic crops. Root-knot nematodes are important in peanut, cotton and soybeans. Lance and reniform nematodes are important in both soybeans and cotton, while soybean cyst nematode only attacks soybeans.
Because of the patchy distribution of nematodes, it is very important that the soil sample be truly representative of the area sampled. The only way to ensure the sample is representative is to collect soil from many spots around the field rather than from only one or two spots. Soil samples should only be collected when soil moisture is suitable for working the field. Avoid sampling under excessively dry, wet or frozen soil conditions.
Soil samples should be taken from around the plant root. Sampling depth may differ for different crops. In the fallow field, samples should be taken from the depth of the root zone of the future crop. Since nematodes have trouble surviving the harsh environment in shallow soil it is best to remove the top 2″ prior to sampling. Keep
Knowing what, if any, nematodes are present in your fields will help determine what treatment options are best for your farm.
Source:uga.edu