Distribution of Citrus virus diseases in the Mediterranean Basin
Further to our report (EPPO document 76/6 - 2812) we would like to inform you of an additional reference which gives precise details on the distribution of Citrus virus and virus-like diseases in the Mediterranean Basin in 1967.
This information was kindly sent to us by Dr Vogel, Station de Recherches Agronomiques de Corse (S.R.A.), San Nicolao.
Reference : BOVE, J.M. (1967). Maladies à virus des Citrus dans les pays du bassin Méditerranéen. Fruits 22 (3) : 125-140.
In addition Dr Vogel made the following comments.
That in the 1957 report (cited in document 2812) the most important fact arising was the spread of tristeza in Spain and its presence in Israel and Turkey. At present, tristeza is the disease against which all other countries in the Mediterranean Basin should take the strictest precautions, especially since, in most countries, sour orange rootstocks are still largely used.
The exact importance of Exocortis and Cachexia-Xyloporosis is difficult to assess from the responses to the questionnaire. In fact, it is only in those countries where extensive indexing is carried out or where susceptible rootstocks are used (P. trifoliata, sweet lime in Palestine) that it is possible to have a precise idea of the percentage infection of trees. It is important to remember that a number of varieties grafted onto sour orange are symptomless carriers of these viruses.
Concerning distribution of scion wood, the S.R.A. voluntarily suspended export of all plant material in 1973 following the discovery of Stubborn virus in certain mother trees. The latter have all been, or are in the process of being indexed for this disease. The embargo will be lifted for a few varieties only (see attached list). If other countries followed this example, the spread of viruses and mycoplasms would be considerably retarded.
Finally, that at the proposed meeting of experts, representatives of non-Citrus growing countries in Europe also be invited. It is evident that these countries receive Citrus plants from tropical countries, particularly ornamentals, which are probably infected with tristeza. While these plants remain under glass, they do not represent a danger, but if planted in gardens, for example in the Mediterranean region of France, they would constitute a risk as sources of infection which could easily be disseminated by aphid vectors. Present legislation in France prohibits import of Citrus material, but one cannot expect inspectors to recognize all the ornamental host plants.
Distribution of Citrus Scion Wood
Station de Recherches Agronomiques de Corse
Station de Recherches Agronomiques de Corse
Following the discovery of infection by Stubborn virus in certain Citrus lines selected by the SRA, it was decided to suspend all export of scion wood from Corsica. Recent results from indexation now permit distribution of the SRA lines below. No guarantee from the Station can be given for those not included on this list.
To avoid all risk of infection the old Station nursery has been largely removed and a new one will not be formed until 1977. It is advisable, for most lines, to limit scion wood distribution during the next two years.
Clementine
SRA lines no. 15, 36, 38, 61, 62, 63, 64 and 71
Mandarin
Anana no. 115 and 163
Commune no. 113 and 118
Carvalhal no. 111
Farichild no. 30
Fortune no. 31
Fremont no. 147
Kara no. 165
Kinnow no. 26 and 117
Murcott no. 180
Ortanique no. 110
Satsuma St Jean no. 108
Satsuma Kowano no. 167
Orange
Hamlin no. 41
Moro no. 24
Parson Brown no. 43
Pineapple no. 42
Shamouti no. 25
Tarocco no.23
Washington Navel no. 141
Grapefruit
Marsh no. 7, 8 and 120
Red Blush no.56
Shambar no. 22
Thompson no.121
Miscellanous
Lime Mexicaine no.140
Lime Tahiti n° 58
Limequat Lakeland no. 151
Limequat Eustis no. 152
Sources
Station de Recherches Agronomiques de Corse, (1976-07)