Location: Subtropical Plant Pathology Research
Title: Copper Sprays and Windbreaks for Control of Citrus Canker on Young Orange Trees in Southern Brazil Authors
|Behlau, F. - UNIVERSITY OF FLORIDA|
|Belasque JR., J. - FUNDECITRUS|
|Bergamin-Filho, A. - UNIV. DE SAO PAULO|
|Graham, J. H. - UNIVERSITY OF FLORIDA|
|Leite, JR., R. P. - IAPAR, BRAZIL|
Submitted to: Crop Protection Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2008
Publication Date: June 1, 2008
Citation: Behlau, F., Belasque Jr., J., Bergamin-Filho, A., Graham, J., Leite, Jr., R., Gottwald, T.R. 2008. Copper Sprays and Windbreaks for Control of Citrus Canker on Young Orange Trees in Southern Brazil. Crop Protection Journal. 27:807-813. Interpretive Summary: Citrus canker continues to be difficult to control especially in Florida where tropical weather including wind and rain spread the disease rapidly with the susceptible citrus types grown in Florida, especially grapefruit. Past work in Argentia on windbreaks has shown that windbreaks are a viable means of suppressing the disease horticulturally. This study undertook to explore the interaction of windbreaks and copper sprays to control the disease with the intent of defining commercially viable strategies for growing citrus in the presence of citrus canker. Unfortunately, in this test windbreaks did not significantly diminish the disease. The authors believe this may be due to the insufficient height of the windbreaks relative to the citrus trees.
Technical Abstract: The benefit of windbreaks and copper sprays for control of citrus canker caused by Xanthomonas axonopodis pv. citri was investigated in a commercial citrus orchard located in a citrus canker endemic area in southern Brazil. Control of canker was evaluated as incidence and severity of lesions on foliage and by the effect on premature leaf and fruit drop for three production seasons. Effect of the treatments on fruit production was evaluated as incidence of citrus canker on prematurely abscised fruits and harvested fruits. Copper application significantly reduced damage to foliage and fruit while windbreaks made little contribution to disease control. Copper sprays increased fruit yield for the three years. This could be attributed to lower incidence of fruit with lesions and fewer fruits abscised due to canker infection. Incidence and severity on the leaves was inversely related to the number of fruits harvested per tree and directly related to the number of fruits abscised per tree.