Wind and Wind-Generated Sand Injury as Factors in Infection of Pepper by Xanthomonas campestris pv. vesicatoria. Ken Pohronezny, University of Florida, IFAS, Everglades Research and Education Center, Belle Glade 33430. Myrine Hewitt, Janice Infante, and Lawrence Datnoff. University of Florida, IFAS, Everglades Research and Education Center, Belle Glade 33430. Plant Dis. 76:1036-1039. Accepted for publication 27 May 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-1036.

Wind and windblown sand were examined for their role in infection of pepper (Capsicum annuum) by the bacterial spot pathogen (Xanthomonas campestris pv. vesicatoria). At four inoculum concentrations from 10⁵ to 10⁸ cfu/ml, significantly more lesions occurred on Jupiter plants wounded by simulated windblown sand than on nonwounded plants. There were also more lesions on pepper plants when leaves rubbed against each other in simulated windstorms than when no abrasion occurred. Numbers of lesions doubled after 10-min exposure to an 8-m/sec windstorm or sandstorm in a wind tunnel. Many more lesions developed on plants that were wounded prior to arrival of splash-dispersed bacteria. At 15 cm from the impact site, 2.1 times more lesions developed on sand-injured plants than on unwounded ones, and at 46 cm, this difference increased to 7.5 times. Greater increases in disease associated with wounding occurred on Early Calwonder than on Ssupersweet 860 and Jupiter. Wounding did not affect disease levels on resistant cultigen PR 9008-321.