Identification of an Alternative Source of Inoculum Causing Bacterial Blight in Cotton

Bacterial blight of cotton, caused by Xanthomonas citri pv malvacearum (Xcm), has been reported by the Cotton Disease Loss Estimate Committee to have had persistent low-level yield effects in select states. Leftover field debris has been well documented as a source of inoculum for Xcm. This study examines a previously unreported reservoir for Xcm in cotton fields. While nonhost plants have been reported in other crop systems that are infected with Xanthomonas species, there are no published reports of nonhosts as reservoirs for Xcm pathogenic to cotton. Molecular testing identifies isolates collected from nonhost plants, and this report demonstrates isolates from those reservoirs can cause disease on cotton in controlled environment testing.