Raúl Avendaño T. y Abdón Guiñez S.1

The behaviour of ten varieties are hereby reportecl: six from North America, two spanish, one french and one local (from which three crops of Foundation seed were included) were established in a soil heavily infested with hoth root knot and stem nematode, located in the irrigated area of the Central Valley of Chile. Yields (in tons of green matter/ha) and population of each variety were controlled annually and at the end of the third season, respectively. Ligüen and Chilean (improved in Arizona) varieties produced better yield during the first two seasons, hut both decreased notoriously during the third season. Moapa, although ranking second dring the year of establishment, improved comparatively its yields, reaching Ligüen and Chilean Arizona during the second season and overpassed them in the last one. Lahontan variety shmved to be highly resistant to menatodes, and although, its establishment was rather slow, its population was better maintained than the other considered varieties.

1 Ingeniero Agrónomo, Proyecto Forrajeras de Riego y Producción Animal, Estación Experimental La Platina, Instituto de Investigaciones Agropecuarias.