Author
BEHLAU, F. - UNIV. OF SAO PAULO, BR | |
BERGAMIN-FILHO, A. - UNIV. OF SAO PAULO, BR | |
BELASQUE, JR., J. - FUNDECITRUS, BRAZIL | |
AMORIM, L. - UNIV. OF SAO PAULO, BR | |
LEITE, JR., R. P. - IAPAR, BRAZIL | |
Gottwald, Timothy |
Submitted to: Meeting Abstract
Publication Type: Proceedings Publication Acceptance Date: 9/30/2005 Publication Date: 11/7/2005 Citation: Behlau, F., Bergamin-Filho, A., Belasque, Jr., J., Amorim, L., Leite, Jr., R., Gottwald, T.R. 2005. Epidemiology, management and effect on yield of citrus canker under endemic conditions in parana, brazil. Second International Citrus Canker and Huanglongbing Workshop, Orlando, FL, November 7-11, 2005. C12, p.22. Interpretive Summary: Technical Abstract: Citrus canker caused by Xanthomonas axonopodis pv. citri was first reported in Brazil in the western region of São Paulo state. Whereas in São Paulo eradication is mandatory, in Paraná state it is not. This fact allowed us to investigate the epidemiology of citrus canker under endemic conditions in Paraná as affected by different control measures (windbreak and copper spray) from December 2002 to April 2005. The experiment was carried out in a commercial orchard located at Ourizona, western Paraná, about 100 km south of São Paulo state. Cultivar used was Pêra on Rangpur lime, aged two years at the beginning of the experiment. Windbreaks consisted of a screen (70% porosity) supported by wood stakes 3 m high. Copper oxychloride was applied monthly, except during the period May-August each year. All treatments showed a fast progress of infection around November-January (wet season) followed by a marked decline after that. Copper spray, windbreak, or combination of the two methods did not completely suppress the disease (Figure 1). Epidemic was more severe in 2003-2004 than in 2004-2005, which corresponded well to the levels of leaf miner in each period (peaks of 60 and 12% of infested leaves, respectively). Despite poor control, copper sprays allowed significant (P<5%) higher yields in 2003-2004 (28.7 versus 13.7 kg/plant in plots with windbreak and 30.4 versus 13.8 kg/plant in plots without windbreak). No differences in yield were detected in 2004-2005 (76.4 versus 72.1 kg/plant with windbreak and 69.1 versus 79.9 kg/plant without windbreak). Contrary to data published in literature, effect of windbreaks in both disease progress and yield was not detected. |