First report of Phyllosticta citricarpa in Tunisia
In March and April 2019, 7 consignments of citrus fruit (Citrus limon and C. sinensis) imported from Tunisia were intercepted by the NPPO of France (EPPO RS 2019/095) because of the presence of Phyllosticta citricarpa (citrus black spot - EPPO A1 List). Following these interceptions, investigations carried out by the NPPO of Tunisia confirmed that the infected lots originated from the Governorate of Nabeul (municipalities of Beni Khalled, Bouargoub and Menzel Bouzelfa). The origin of this outbreak is unknown, but it is suspected that infected plant material has been brought illegally into this area (import of citrus plants for planting is prohibited in Tunisia) and that the floods which occurred in September 2018 in the Governorate of Nabeul facilitated fungal dispersal. Emergency measures are being elaborated in consultation with all stakeholders (e.g. citrus fruit growers, technical institutes, researchers). In the infected area (covering approximately 2 000 ha), a chemical control programme will be applied (including the registration of additional fungicides). A surveillance programme is being developed, samples will be collected and tested using molecular methods to delimit the extent of the disease in Tunisia (as of July 2019, 110 analyses have been requested). Awareness raising activities will be launched to train professionals on symptom recognition and control measures.
At national level, a three-year strategic plan to control P. citricarpa is being developed by the NPPO in consultation with all stakeholders and will include: regulatory measures concerning plant movements and certification of citrus plants for planting, increased surveillance in all citrus-growing areas with a focus on the production sites of plants for planting, improvement of the quarantine laboratory infrastructures, application of a control programme using cultural and chemical methods over an area of 10 000 ha (estimated at more than 5.7 million Tunisian Dinars ≈ 1.7 million Euros), launching of awareness raising campaigns targeting growers and the general public, and development of research activities about the epidemiology, biology and control of the disease under Tunisian conditions (a budget of 100 000 Tunisian Dinars per year (≈ 30 000 Euros) has been allocated).
The situation of Phyllosticta citricarpa in Tunisia can be described as follows: Present, only in some areas (first found in 2019 in the Governorate of Nabeul), under official control.
Sources
NPPO of Tunisia (2019-07).