Disease Note

Pratylenehus brachyurus Associated with Vine-Dying of Vanilla Plants in Tonga. H. Z. Stier, Plant Pathology Section, Department of Agriculture, Nukualofa, Kingdom of Tonga. Plant Dis. 68:628. Accepted for publication 2 April 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-628d.

Pratylenchus brachyurus (Godfrey 1929) Filipjev & Schuurmans Stekhoven 1941 has been found on vanilla (Vanilla planifolia Andr.) plants on Tongatapu and Vava'u islands of the Kingdom of Tonga. P. brachyurus/ was able to enter vanilla roots in agnotobiotic and axenic culture. Feeding adults, larvae in all stages, and eggs were found in the roots. Vine-dying was observed on 50% of vanilla plants surveyed on Tongatapu, and P. brachyurus was usually associated. Helicotylenchus dihystera (Cobb 1893) Sher 1961 was also found but was not associated with vine-dying. Because symptoms are similar to those caused by Fusarium wilt (F, oxysporum Schlecht. f. sp. vanillae (Tucker) Gordon), the most widespread and damaging disease in vanilla-growing countries, the presence of P. brachyurus may be easily overlooked. Whether the nematode contributes to loss of vanilla plants to wilt is not known.