First report of potato wart disease in Turkey

In October 2003 potato wart disease was detected for the first time on potato tubers in Aybasti county (Ordu province, Black Sea Region), a noneconomically important potato-growing district. In the same year the disease was also found in Niǧde and Nevşehir, two commercially important potato-growing provinces in central Anatolia. Potato cultivars Agria, Donella, Granola, Marfona and Russet Burbank grown in Niǧde and Nevşehir provinces were affected with a low incidence of disease (<1%). In Ordu province only a local variety, grown for home consumption, showed disease symptoms. The disease exhibited typical symptoms on tubers ranging from small to large warts that completely transform the tuber into a dark mass. Galls of various colours, including shades of green and yellow but mostly brown, appeared on the tubers by the end of the season. Summer and winter (resting) sporangia were observed from galls of different colours. Resting sporangia were typical for the chytrid fungus Synchytrium endobioticum, having irregularly shaped, dark brown walls. They were aseptate, light golden-brown in colour, thick-walled, smooth, 40–50 µm diameter, and spherical to ovoid in shape (Walker, 1983). Resting sporangia were isolated from infected tubers and soil surrounding infected plants using a method developed by Hampson & Thompson (1977). Pathogenicity of the causal agent was proved by the Glynne–Lemmarzalh method (Glynne, 1925; Lemmerzahl, 1930) by inoculating potato sprouts at 1–2 mm long with fresh wart tissue and incubating the plants at 18 ± 1°C. Sporangia were reisolated from warts observed 2 months later. Noninoculated controls did not show any symptoms. The disease is now present on neighbouring potato fields covering 908 and 23 ha in Nevşehir and Niǧde provinces, respectively, and on land covering ≈10 ha in Ordu province. This is the first report of potato wart in Turkey. The Ministry of Agriculture has been employing the EU (1969) Council Directive 69/464 of 8 December 1969 on control of potato wart disease. Disease surveys for this pathogen are continuing in Turkey. This work was supported by the Turkish Ministry of Agriculture.