Disease Note

Occurrence of Watermelon Mosaic Virus 1 in Niger. J. -C. Thouvenel, Laboratoire de Phytovirologie, ORSTOM, Adiopodoumé, B.P. V-51, Abidjan, Ivory Coast, West Africa. C. Fauquet, and D. Fargette, Laboratoire de Phytovirologie, ORSTOM, Adiopodoumé, B.P. V-51, Abidjan, Ivory Coast, West Africa. Plant Dis. 70:173. Accepted for publication 9 October 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-173f.

In December 1982, a large field of pumpkins (Cucurbita pepo L. ‘Rouge vif d’Etampes’) near Arlit, Niger, was infected by a serious viral disease. The cause appeared to be watermelon mosaic virus 1 (WMV-1), on the basis of similarities in host range, symptomatology, virus properties, and serological relationships (the isolate was serologically related to two isolates of watermelon WMV-1, antisera obtained from D. E. Purcifull and J. B. Quiot). WMV-1 has been reported in Morocco, North Africa, and in South Africa, but this is the first report of the virus in tropical Africa. Diplocyclos palmatus (L.) C. Jeffr. seems to be a useful local lesion host for WMV-1. The disease did not appear to be seed-transmissible (more than 300 seeds from diseased pumpkins were examined), and the source of the inoculum is unknown and puzzling, as a sand desert surrounds Arlit.