Crop rotation controls barley root-knot nematode at Tulelake

THE BARLEY ROOT-KNOT NEMATODE, Meloidogyne naasi Franklin, 1965, was found causing economic damage to barley in the Klamath Basin near Tule-lake, California, in 1964. The species parasitizes barley in England and Wales and has been reported from sugar beets in Belgium. It also occurs in Illinois, Kansas and Oregon. Known infestations in California are in the Tulelake area, and a few locations in southern California where the nematode has been found on the roots of turf grasses. The infestation in the Tulelake area involves several thousand acres that have been cropped almost continuously with barley since the land was reclaimed. Other crops sometimes grown in the infested area include alfalfa, oats, potato and wheat.