Fire blight in Spain: Situation and monitoring

Abstract

Fire blight caused by Erwinia amylovora was first identified in Spain in late summer 1995 in a field survey in Gipuzkoa (Euzkadi). The disease was found in a cider apple orchard close to the Atlantic French border. After discovering the first outbreak, nurseries and orchards were more closely surveyed in all Spanish regions. Plants with symptoms were analysed by isolation, enrichment-DASI ELISA and PCR. During these surveys several new outbreaks were discovered in Gipuzkoa (Euzkadi) in 1996 and 1997 and in Navarra, a region located beside the first outbreak. Apple and pear orchards, quince, loquats and ornamental hosts were found infected. In 1996 fire blight was found in Crataegus plants in a nursery located in Segovia (Castilla-Leon) and eradicated. No relation with the previous outbreaks was found and the plants infected came from importation. In 1998 the disease was detected in another nursery in Guadalajara (Castilla-La Mancha), which imported plants in 1996 from the same origin. Another outbreak was found in a few pear orchards in Lleida (Catalunya), the same year and eradication measures were also taken. In spite of intensive surveys carried out in other Spanish regions, no new outbreaks of the disease were found. Fire blight is not yet widespread in Spain and several measures have been taken for eradication in the different areas, according to each situation. Comparison of Spanish isolates with other European strains using biochemical tests, serological techniques, PCR and inoculation in pear fruits and shoots confirmed the identification.