Present address: Plant Pathology Department, University of Florida, Gainesville, FL 32611, USA.
Annual and polyetic progression of citrus canker on trees protected with copper sprays
Version of Record online: 14 SEP 2010
No claim to original US government works. Plant Pathology © 2010 BSPP
Volume 59, Issue 6, pages 1031–1036, December 2010
How to Cite
Behlau, F., Amorim, L., Belasque, J., Bergamin Filho, A., Leite, R. P., Graham, J. H. and Gottwald, T. R. (2010), Annual and polyetic progression of citrus canker on trees protected with copper sprays. Plant Pathology, 59: 1031–1036. doi: 10.1111/j.1365-3059.2010.02344.x
- Issue online: 2 NOV 2010
- Version of Record online: 14 SEP 2010
- Published online 14 September 2010
- Citrus sinensis;
- disease control;
- logistic model;
- sweet orange;
- Xanthomonas citri subsp. citri
The effects of copper sprays on annual and polyetic progress of citrus canker, caused by Xanthomonas citri subsp. citri, in the presence of the Asian citrus leafminer (Phyllocnistis citrella), were evaluated in a study conducted in a commercial orchard in northwest Paraná state, Brazil, where citrus canker is endemic. Nonlinear monomolecular, logistic and Gompertz models were fitted to monthly disease incidence data (proportion of leaves with symptoms) for each treatment for three seasons. The logistic model provided the best estimate of disease progress for all years and treatments evaluated and logistic parameter estimates were used to describe polyetic disease dynamics. Although citrus canker incidence increased during each of the seasons studied, it decreased over the whole study period, more so in copper-treated trees than in water-sprayed controls. Copper treatment reduced disease incidence compared with controls in every year, especially 2004–2005, when incidence was ca. 10-fold higher in controls than in treated plots (estimated asymptote values 0·82 and 0·07, respectively). Copper treatment also reduced estimated initial disease incidence and epidemic growth rates every year.