Xanthomonas vesicatoria on Capsicum chinense in Grenada and Barbados
The production of 'hot pepper' Capsicum chinense, has recently increased in Grenada and Barbados. Between 1992 and 1995, the production on both islands has increased on average by 500 %. The main cultivars are Indian Red and Scotch Bonnett. C. chinense is usually grown in rotation with capsicum (Capsicum annuum) and tomato (Lycopersicon esculentum). So far, Xanthomonas vesicatoria (EPPO A2 quarantine pest) was not reported on C. chinense, but since 1993, outbreaks have been observed on this crop. In parallel, a switch in control methods also took place, from almost total dependence to copper to frequent use of zinc. Studies conducted on bacterial populations of X. vesicatoria have showed important and complex changes in race composition in Grenada and Barbados. The general trend is a gradual increase of bacterial isolates which are resistant to zinc, and of races which are able to overcome resistance conferred by certain resistance genes (in particular to gene Bs2 which confers resistance to several X. vesicatoria capsicum races). It has been shown that all races prevalent on C. chinense overcome the resistance gene Bs2. However, despite the preponderance of X. vesicatoria races overcoming gene Bs2 on C. chinense, the generally susceptible tomato and capsicum cultivars planted in the field were not significantly affected by them.
Gore, J.P.; O'Garro, L.W. (1999) The advent of bacterial spot of hot pepper in Barbados and Grenada.
Caraphin News, June 1999, no. 18, IICA Barbados, pp 3, 4 & 10.
Gore, J.P.; O'Garro, L.W. (1999) Xanthomonas campestris pv. vesicatoria from bell pepper and tomato in Barbados undergoes changes in race structure, virulence and sensitivity to chemical control agents.
Journal of Phytopathology, 147(7-8), 397-402.
O'Garro, L.W.; Gore, J.P.; Ferguson, E. (1999) Races of Xanthomonas campestris pv. vesicatoria overcoming the gene Bs2 for bacterial spot resistance in pepper, prevalent on Capsicum chinense in Barbados and Grenada and weakly pathogenic on bell pepper and tomato in the field.
Plant Pathology, 48(5), 588-594.