Greensboro, North Carolina
February 10, 2009
Source:
Syngenta Crop
Protection-US
After several decades of reprieve for growers, an indigenous and
damaging pest is again creeping through the Corn Belt. Nematodes
are making a come-back.
While traditional production practices hindered nematode
populations in corn, cultural changes in today’s production have
caused their recent increase. There are three major changes that
have contributed to this growth – and that will continue to
encourage growth in the future.
First is an increase in no-till and reduced-till farming
methods. Because most nematode species are sensitive to tillage,
no-till and minimum-till production practices can create an
environment where certain nematode species are able to flourish
year after year.
Second is a change in rootworm management technology. Pyrethroid
insecticide chemistries and CRW-traited corn don’t suppress corn
nematodes as did the older carbamate and organophosphate
insecticide formulations.
Third is an increase in corn-on-corn planting, which allows
nematode populations to prosper. A rotation with alfalfa or
another non-host crop can help hinder life cycles.
Corn Nematode Damage
Damage caused by corn nematodes is difficult to identify because
symptoms can easily be attributed to other causes such as
herbicide injury, diseases, micronutrient deficiencies or the
result of harsh environmental conditions such as drought. Some
species of nematodes may not cause economic injury on their own,
but can interact with other problems, such as fungal pathogens
and insects, to intensify corn yield loss. Oftentimes, there are
no visual symptoms, but corn yield is impacted. The only way to
accurately identify nematode populations is through collection
and analysis of soil and root samples.
Nematode Mapping Project
To measure the prevalence of nematodes in corn fields, Syngenta
Seed Care launched a corn nematode mapping project in 2007. In
the first comprehensive study of its kind in the Midwest,
Syngenta Seed Care sampled three fields in each county that
grows at least 25,000 acres of corn in the Midwest Corn Belt.
The fields sampled were randomly selected – the only criterion
was the fields had to be at least 10 miles apart. There was no
pre-selection for soil type or tillage, and the samples were
taken from corn-on-corn and corn-on-soybean rotation fields.
Samples were processed by five university labs and one private
lab. The results mapped intensity by species and overall
nematode populations for every county included in the study.
While species and populations varied, nematodes were found in
every county included in the survey.
Syngenta Seed Care recognizes the threat that growers face with
corn nematodes and is working to bring to market a corn seed
treatment nematicide to help manage the threat of yield loss
caused by corn nematodes. For more information, please contact
your Syngenta Seed Care sales representative.
©2008 Syngenta. Syngenta Crop Protection, Inc., P.O. Box
18300, Greensboro, NC 27419.
Syngenta Seed Care™ is a trademark of a Syngenta Group Company. |
|
