Disease Note

First Report of Ditylenchus destructor in Portugal. L. G. L. Reis, Departamento de Fitopatologia, Estação Agronómica Nacional, 2780 Oeiras, Portugal. Plant Dis. 69:451. Accepted for publication 9 January 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-451b.

In July 1984 in northeastern Portugal, the potato rot nematode (Ditylenchus destructor Thorne, 1945) was found in one of seven hop (Humulus lupulus L. ‘Brewer’s Gold’) fields surveyed for nematodes. Forty root and soil samples from the seven fields were examined, and the nematode was identified on the basis of the morphometrical characters of females and males. In the infested field, D. destructor was recovered from all 10 root and rhizosphere samples collected in circular areas with stunted hop vines and also from areas with vigorous plants. Densities ranged from 320 to 4,400 specimens per liter of soil; roots did not show signs of injury. Potato tubers inoculated with males and females recovered from hop roots showed large numbers of D. destructor 30 days later. D. destructor is widely distributed in Europe and, in the Mediterranean region, has been reported from France, Rumania, Greece, Yugoslavia, and Cyprus.