Maximize root growth this fall

By Lane Tredway, Ph.D., technical services manager for Syngenta

While it’s important to manage root growth and plant health all year long, fall and spring are key times to grow roots in the south and transition zone, both in cool- and warm-season grasses. Nematodes are one of the key pests that can hamper root growth during these times. Plant-parasitic nematodes need living roots to grow and reproduce, so they are most active when the turf roots are growing. Although symptoms of nematode damage often appear during the summer, most of the damage was likely done weeks or even months beforehand.

Making fall applications 

Fall applications of Divanem® nematicide have been shown to increase root depth and density in turfgrasses infested with nematodes. Divanem has broad-spectrum activity against the most important turf nematodes, including Anguina, sting, root knot, lance and spiral, so it is a valuable component of any nematicide program.

Broadcast rates of 12.2 fl. oz./acre on a 21- to 28-day interval are effective for preventive applications or when initial nematode populations are low. Where populations are very high or turf damage has occurred, Divanem may be applied at a spot-treatment rate of 12.2 fl. oz./10,000 ft2 on a 21- to 28-day interval. The spot treatment rate provides greater protection against high nematode populations and more rapid turf recovery as a result.

Click here for sampling tips and to find a nematode sampling lab near you.
Divanem is compatible with fungicides like Velista® and Heritage® Action™, which are also commonly applied in the fall to prevent key root diseases like spring dead spot and take-all root rot. Tank-mixtures of Divanem with these fungicides consistently provide further enhancements in root growth and turf quality. Divanem is packaged with Heritage Action in a convenient Multipak that offers 10% savings on this root health solution

For best results, Divanem should be tank-mixed with a soil surfactant, applied to wet turf early in the morning, and watered-in immediately after application with 0.25” of irrigation. These steps are important to wash the active ingredient from the turf foliage and help it to penetrate through the thatch layer.

Treatments: Applied four times on a 28-day interval (June 26, July 27, August 21 and September 30, 2016). Nematodes present: Sting, Lance and Root-knot. Photos taken September 27, 2016. Trial by Neil Young, Turfgrass Environmental Research, Inc. Photo source: Neil Young. Fort Lauderdale Country Club in Plantation, Florida.

For more information about Divanem and nematode management, visit Nematode Knowledge or

Performance assessments are based upon results or analysis of public information, field observations and/or internal Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace.

All photos are either the property of Syngenta or are used with permission.

Always consult the product label for complete use and application information 

© 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 and proper use. Divanem is a Restricted Use Pesticide. Syngenta supports a FIFRA Section 2(ee) recommendation for Velista fungicide to control summer patch, brown ring patch, spring dead spot, fairy ring, leaf and sheath spot and rapid blight on all turf types. Action, Divanem®, GreenCast®, Heritage®, Velista® and the Syngenta logo are registered trademarks of a Syngenta Group Company. All other trademarks are the property of their respective owners.

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