Survival of the anthurium blight pathogen, Xanthomonas axonopodis pv. dieffenbachiae, in field crop residues

Bacterial blight, caused by Xanthomonas axonopodis pv. dieffenbachiae (Xad) , is a major threat to the anthurium cut flower industry worldwide. Two fie ld trials in Hawaii evaluated the long-term persistence of Xad in artificia lly-infested crop residues. Xad survived in leaf, petiole, and root residue s for as long as 4 months when tissues were left on the surface or buried 1 5 cm deep. Survival was considerably shorter (approximately 20 days) outsid e of residues. Xad that was recovered from residues over a period of 4 mont hs retained pathogenicity. Xad was isolated from living roots of naturally- infected plants which further suggests that roots left in the field after c ulling may be particularly important, but overlooked, inoculum source. This information is key to determining minimum fallow periods before replanting devastated fields.