The nematode D. dipsaci (Kuhn) Filipjev is the second pest in importance to the garlic crops of Spain. The problem is severe in irrigated fields where different species are used in rotation. A study on the physiological races of the nematode was undertaken. Twenty four different plant species were inoculated, when very young, pouring fourth stage larvae on the roots. Two different, a Spanish and a Californian, isolates from garlic were compared with one English oat race. The pots were mantained in a greenhouse for three months at moderate to low temperature. The plants were examined for eggs and active forms. The results show that the garlic isolates produce a response similar to that of the « onion race }}.
