Dr. Saad Hafez, Extension Professor, Nematology, University of Idaho (A past graduate of UC Davis & internationally known expert on nematodes)

University of Idaho nematologist Saad Hafez thinks Idaho's agricultural producers should consider including green-manure crops in their rotations. The fall- or spring-planted crops-typically oilseed radishes or mustards-build and replenish soils when they're turned under after a few months' growth. They also slash nematode populations by serving as nonhosts or poor hosts for the sugarbeet- and potato-damaging pests as well as by releasing biofumigating chemicals and activating natural enemies. For the past eight years, Hafez has studied crop rotations involving sugarbeets, potatoes, wheat, sweet corn, beans and oilseed-radish green manures. Last fall, he started a new study that includes onions and that's slated to continue for a dozen years. Not only will Hafez and other researchers measure the impacts of onions in these rotations, but they will examine the physical changes in soil produced by the green-manure crop. "You get great benefits from green-manure crops, even if you don't have sugarbeet cyst nematodes or other nematodes," Hafez says. For example, as organic matter builds, soil tilth and water-holding capacity increase and compaction and erosion decrease. The organic matter slowly releases nitrogen into the soil, reducing the need for synthetic nitrogen without leaching excess fertilizer into > groundwater. Hafez says more producers would use green-manure crops, but they haven't been able to fit them into their crop rotations. "The stumbling block is the timing," he says. "During the time that growers would be planting the green-manure crop, they are harvesting other crops or getting the ground ready for next year, so their labor and equipment are tied up." Selecting the right green-manure crop is also critical: some will host diseases, weeds or even the very nematodes growers would like to control. Others aren't as frost tolerant as they should be. Hafez says new oilseed radishes not yet available in the marketplace should entice more Idaho potato and sugarbeet growers into giving green-manure crops a try within a few years: the varieties Defender and Comet cut populations of both sugarbeet cyst nematodes and potato-damaging Columbia root-knot nematodes by 95 and 99 percent, respectively, in his greenhouse experiments. "Their main advantage is that they reduce both of these nematodes," says Hafez. Previously, green-manure crops that discouraged one nematode encouraged the other. In addition, Defender and Comet reach nematode-inhibiting growth stages in six to eight weeks-two weeks earlier than other varieties. That will give growers more opportunities to squeeze them into their rotations after a fall-harvested crop or before a spring-planted crop. The best older varieties of oilseed radish green-manures curbed populations of Columbia root-knot nematodes by 50 percent and sugarbeet cyst nematodes by 80-90 percent, Hafez says. He will evaluate the effectiveness of Defender and Comet in the field and hopes they will be available to Idaho growers by 2006. In the 1998-2004 study, Hafez and colleague Sundararaj Palanisamy determined that potatoes and beans suppress sugarbeet cyst nematodes more than wheat or sweetcorn do. In the current and longer study, Hafez will study not only the impacts of six crops but of fall-planted oilseed-radish green-manures included once, twice or three times over the course of 12 years. "If one year is enough, we don't need two," he says.

It was Saad Hafez who found another nematode in eastern Idaho that prompted Japan to temporarily ban U.S. potatoesDigg this storyDel.icio.us bookmarkPhotos by Chris Butler / cbutler@idahostatesman.com Dr. Saad Hafez, a University of Idaho Extension professor of nematology, shares a lighter moment with his staff as they tease him about his new celebrity status Monday at the U of I's Parma Research and Extension Center.Hafez discovered a nematode late last year that was confirmed recently by an agricultural-science research organization.The microscopic worm has been named for him.ELSEWHERESaad L. HafezSaad Hafez was doing a day's work last year, looking at soil samples through a microscope, when he saw a nematode he hadn't seen before.Until he sent it to a British-based intergovernmental scientific organization that studies agricultural and environmental problems, he had no idea that no one had previously identified the microscopic critter.This summer, a taxonomist for the organization named it after him."I sent it to them because I didn't know what it was," Havez, 60, said.The organization , CABI, for Commonwealth Agricultural Bureaux International , "was very generous to name it after me."Hafez was born in Cairo.He came to the United States in 1975 when he was offered a scholarship at University of California-Davis, where he earned a Ph.D. After he graduated, he was hired to work at Kansas State University in Manhattan, Kan., before moving to Idaho 26 years ago.He went into nematology because not very many people were in the field at the time.His research is focused on controlling nematodes and creating educational programs for growers and agents along with recommendations for treatment.Nematodes are threadlike worms ranging in size from microscopic creatures that feed on plant matter to larger ones that feed on animals.Nematodes include heartworms in dogs and pinworms in people, Hafez said.There's also the Nematode Songbook Web site with songs like "The Happy Nematologist" to the tune of "The Happy Wanderer," and "The Nematode Marching Song" to the tune of "Onward Christian Soldier."In Idaho, certain nematodes , not the one named for Hafez , can devastate potato, sugar beet and onion crops, Thompson said.Those potato fields will be off limits for seven years, planted only with a cover crop of oil radishes, Hafez said.The pale potato cyst nematode is so contagious that farm equip-ment must be steam-cleaned before it can leave the quarantined area.The pale potato cyst nematode is new in Idaho and in the U.S., he said.It has been reported in Canada but is a European variety.No one knows how it came to the U.S."It's a very small animal," Hafez said.

Saad Hafez, a nematologist with the University of Idaho Research and Extension Center in Parma, made the initial PCN discovery in 2006 from tare dirt taken from a Blackfoot grading facility. He believes PCN has been kept in check by nematocides sprayed to control other nematodes that pose a greater threat to spuds. "They should work on management, not eradication," Hafez said.