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GRKN Resources

NC State Extension has partnered with the N.C. Department of Agriculture and Consumer Services (NCDA&CS) and the N.C. SweetPotato Commission to assist our state’s sweet potato operations in the timely and accurate identification of GRKN-infected sweet potatoes.

What is GRKN?

GRKN, or Guava Root-Knot Nematode, refers to microscopic worms in the soil that can infect sweet potatoes (among other crops), forming knots or galls on the roots and ruining entire crops. GRKN is a major threat to the N.C. sweet potato industry, but you can make a difference.

Side-by-side comparison showing non-infected sweet potatoes versus sweet potatoes infected with Guava Root Knot Nematode

Available Materials

We’ve developed resources that can assist you in educating and equipping your local growers to combat this issue. The current materials are geared toward packing-shipping operations, but they can be used with grower operations as well.

Print Resources

Click each item below to view a PDF that can be downloaded and used as needed:

You can also view our Sweet Potato Root-Knot Nematode Publication from NC State Extension for more information.

Video Resources

NC State Extension developed two informational videos to educate sweet potato producers on how to identify and manage GRKN within their operations. These videos can be used by agents or specialists in workshops, as well as shared with producers for use in local training.

NCDA&CS provided a training video to assist sweet potato packing-shipping operations with meeting all GRKN compliance stipulations.

The video is available in English and Spanish, and can be paired with the print resources for local training purposes. The password to view these videos is: Plantprotect1!


NC State Extension is pleased to announce the availability of a new training program for workers in sweet potato packing houses regarding the Guava Root-Knot Nematode (GRKN).

The GRKN Training Program is an interactive session with a focus on creating a GRKN prevention culture in packing plants by educating workers. Find more information.


If you suspect GRKN-infected sweet potatoes in your farmers’ fields, or you would like to request these resources for local training efforts, contact your regional NCDA&CS plant specialist immediately at to discuss and arrange a quick inspection.