ABSTRACT


Gonzalo Gil Z.1
 

This study was under taken to determine the distribution of the stem nematode of alfalfa in the Central Region of Chile and to test various varieties for resistance to the nematode. Alfalfa fields from Coquimbo to Ñuble were inspected and samples were collected for microscopic examination. Infestation was observed in Coquimbo, Aconcagua, Valparaiso, Santiago and O'Higgins, and in Colchagua it was observed in red clover. The resistance of several varieties oí alfalfa was studied under green.house conditions. Soíl tor the greenhouse benches was taken from infested field plots, and seedlings were inoculated with a suspension containing the stem nematode. Plants were scored for susceptibility and resistance three months after inoculation. The variety Lahontan was signiticantly more resistant than any other variety. A strain from Argentina (M5) also showed a high degree of resistance; the varieties Talent and Hunter River showed only moderate resistance.

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1 Ingeniero Agrónomo, ex funcionario de la Oficina de Estudios Especiales.