When it comes to nematodes, you have to emphasize management, said Saad Hafez, a nematologist at the University of Idaho's Parma Research and Extension Center, during the Washington-Oregon potato conference in Kennewick, Washington.
"It's not something you can eradicate or eliminate," he
"Fumigation works very well controlling nematodes."
said that current fumigants in use to control nematodes and potato diseases include Telone II, Telone C-17 and C-35 1,3D, Vapam (metam sodium), Metam Potassium and Metam Ammonia.
"Metam sodium is not really a true fumigant but reacts like a fumigant.
It's a contact biocide," said Hafez
"I want to emphasize that we've been working on a lot of new chemistry," said Hafez
"In the last 10 years a lot of chemical companies have shown interest in developing new nematicides.
For years the list of nematicides was a short one that included Vydate, Mocap, Nimitz and Admire but Hafez
said that there have been promising results with new products.
With all the non-fumigant products he
said that both the application method and the timing of application is very critical for the treatments to be successful.
said that Nimitz, a nematicide produced by Adama, is a good nematicide but it doesn't move well in the soil and is best used in combinations with other products, not as a standalone treatment.
Recently introduced products have been discovered to have efficacy against nematodes.
said that Bayer CropScience's insecticide Movento has been effective against nematodes.
said that Movento works systemically.
The first application should be at the plant's roseate stage and followed 14 days later by a second application.
"You have to apply it when you have enough foliage for penetration and you have to apply it with a surfactant," Hafez
"Movento is a very active nematicide, not a standalone treatment," he
"You have to do it in combination with Vapam, Vydate or Mocap."
recommended using Absorb, a soil penetrant, to aid in water movement with nematicides.
"We found out that when we mix Absorb with Vapam, we get better results controlling nematodes," he
said that planting non-host plants or green manures are both effective preventative strategies to reduce nematodes.
said that a study on corn, beans and wheat showed that corn is a bad rotation crop because the nematode can survive in the corn roots.
Green manure crops Hafez has been testing include mustard, radish, beets, lentils, cabbage and onion.
"Basically, if you're planting brassica, radish or mustard, you're adding natural vapam to the soil," Hafez
said that the best solution to stop the spread of nematodes is to clean your equipment before moving from a field, to not use wastewater and to use certified seed.
"You can spread nematodes, especially root-knot, very easy with infected seed," he
"If you can leave the field fallow for one summer you can get 90 percent control of root-knot," Hafez