In order to prevent Karnal bunt from entering Nebraska, it is recommended that wheat producers who use custom harvesters or custom seed cleaners follow "Best Management Practices." All combines, grain trucks, and trailers coming from out-of-state should be thoroughly cleaned before entering Nebraska. Also seed cleaners should be cleaned out thoroughly.

Low-pressure, high-volume water is recommended for cleaning. The goal is to remove virtually all of the debris to avoid contaminating the next field. This recommended protocol is not as stringent as the protocol used by USDA-APHIS for cleaning combines used in the quarantine area.

• Clean the feeder house and reel, open the trap doors, then run the machine until the loose grain is all out.
• Select an area with access to a water hydrant for cleaning.
• Remove the header and clean it separately.
• Park on pavement where waste grain can be swept up and disposed of properly. The combine can be tilted to help drain the horizontal augers.
• Open all access doors, traps, and elevators and remove the sieves.
• Run the machine until the loose grain is all out.
• Use a garden hose and nozzle to dislodge debris. Start at the front and clean in the direction that grain flows from the machine so, if the machine is run to shake debris loose, it will not contaminate the area that has already been cleaned.
• If possible, remove the concaves and wash the cylinder area. Use water to thoroughly flush them in place. Continue cleaning toward the back of the machine.
• Clean the grain tank and unloading augers.
• Run the machine again to shake any remaining grain loose.
Clean debris and grain from the undercarriage.
• Dispose of waste grain, weed seeds, and debris in a landfill or bury it deeply.

Note: Cleaning a combine can be hazardous, so always make safety a top priority. Wear proper eye protection and be especially careful when running the machine with the access doors open.