Nematodes are microscopic, thread-like roundworms that inhabit the soil and feed on root systems of crops, causing symptoms that can be mistaken for other issues.
Male Lance nematode- Corn nematodes occur in every soil type, not just sandy soils.
- Symptoms may include chlorosis, stunting, root damage and yield loss. Usually there are no visual symptoms, but yield may be impacted.
- In contrast to soybeans, there are many types of nematodes that can damage corn.
- Many of the same nematodes that attack cotton, such as the southern root-knot nematode, are also pathogenic to corn.
Categories Based on Feeding
- Endoparasitic – completely enters the host to feed from within
- Semi-endoparasitic – partially enters the root to feed, but also feeds from the outside
- Ectoparasitic – feeds only from the outside
Spiral nematodeDiagnosing
- Damage such as discoloration, stunting, and reduction in stalk diameter and root weight is often misdiagnosed as herbicide injury, disease, micronutrient deficiencies or the result of harsh environmental conditions such as drought.
- Some species do not cause direct injury on their own, rather they interact with other problems, such as fungal pathogens and insects, intensifying the symptoms.
- Soil and root sample analysis can provide confirmation of symptoms caused by nematode presence. A split field plot design comparing Avicta® Complete Corn with Vibrance® seed treatment versus a seed treatment without a nematicide may help determine actual yield loss due to nematodes.
Management Considerations
Dagger nematode- In the past, organophosphate and carbamate insecticides have secondarily provided some suppression of nematodes, minimizing nematode populations to the point that damage went unnoticed. The switch to pyrethroid insecticides and the introduction of transgenic insect-resistant corn has left the door open for nematodes to thrive.
- The increase in no-till farming operations has created a more hospitable environment for nematodes, which are sensitive to soil disturbance.
- Increased corn-on-corn production gives nematode populations the resources to thrive year after year.
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©2021 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties. Please check with your local extension service to ensure registration status. Avicta Complete Corn 250 is a Restricted Use Pesticide. For use by certified applicators only. Growers planting Avicta treated seed are not required to be certified applicators. Avicta technology is protected by U.S. Patent No. 6,875,727. Avicta®, Golden Harvest®, Vibrance and the Syngenta logo are trademarks of a Syngenta Group Company. All other trademarks are the property of their respective third-party owners.