Present situation of citrus tristeza closterovirus in Spain
The article of Cambra et al. (1995) recalls that citrus tristeza closterovirus (EPPO A2 quarantine pest) was probably introduced into Spain in the 1930s, but was only detected in 1957 when the disease reached epidemic levels. Since then, more than 190 million trees grafted on sour orange died. In Spain, most citrus trees are grown in the Comunidad Valenciana (80 %), and in Andalucía and Murcia. Citrus orchards are also found in Tarragona, Baleares and Canarias. Today, tristeza is the most serious disease of citrus crops and surveys are regularly carried out. During recent years, these surveys have shown an increase in disease incidence, especially in the Comunidad Valenciana, Murcia and Ebro delta. This change seems to be partly due to an increase of populations of the vector Aphis gossypii. For example, in the Comunidad Valenciana, mean percent infection was 14 % in 1989, and reached 46 % in 1995. In Spain, it is now considered that 39 million trees are infected (30 % of the citrus crop). The authors took the view that this may be the opportunity to renew the infected orchards and promote plantation of tolerant rootstocks. They also point out that the use of new diagnostic methods like immunoprinting ELISA can provide useful tools in surveying citrus orchards, and can facilitate the decision-making process of the grower when infection is found, as it is easier to evaluate the level of infection.
Sources
Cambra, M.; Camarasa, E.; Gorris, M.T.; Roman, M.P. (1995) Distribución actual de la trizteza de los cítricos y nuevos métodos de diagnóstico.
Phytoma España, No. 72, 150-158.