Skip to main content
ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #338029
Title: Effect of windbreaks on wind speed and citrus canker incidence on grapefruit

Author
item GRAHAM, JIM - University Of Florida
item MYERS, MONTY - University Of Florida
item Gottwald, Timothy
item Bock, Clive

Submitted to: Citrus Research and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2016
Publication Date: 12/19/2016
Citation: Graham, J.H., Myers, M.E., Gottwald, T.R., Bock, C.H. 2016. Effect of windbreaks on wind speed and citrus canker incidence on grapefruit. Citrus Research and Technology. p. 114.

Interpretive Summary: Citrus canker causes unsightly blemishes on citrus, making it unacceptable for sale as fresh fruit. Thus for fresh grapefruit the goal is to maximize pack-out by minimizing canker lesions on fruit. The objective of these trials was to determine the relationship between wind speed and incidence and severity of citrus canker on 5 to 7 yr-old ‘Ruby Red’ grapefruit trees located in two trial blocks surrounded on all sides by a 6 to 10 m tall Corymbia torelliana windbreak. The number of wind gusts =18 km/h increased with distance from the windbreak. The highest fruit canker incidence occurred in approximately the central zone of the block and the lowest incidence was found nearest windbreaks. Number of wind gusts and canker were linearly related, i.e., the greater the number of gusts, the higher the fruit disease. As the number of wind gusts increased with distance from the windbreak, incidence of unsightly wind scar also increased. These results confirm that windbreaks are a highly effective method for protection of fruit from infection by Xanthomonas citri subsp. citri, as well as physical damage from wind buffeting.

Technical Abstract: For fresh grapefruit the goal is to maximize pack-out by minimizing canker lesions on fruit. The objective of these trials was to determine the relationship between wind speed and incidence and severity of citrus canker on 5 to 7 yr-old ‘Ruby Red’ grapefruit trees located in two trial blocks (~4.5 ha) surrounded on all sides by a 6 to 10 m tall Corymbia torelliana windbreak. The experiment was conducted from 2013 to 2015. A series of weather stations were deployed in east-west and north-south directions across the orchards to measure the effect of proximity of citrus trees to the windbreak on wind speed expressed as the number of wind gusts =18 km/h, and to determine the relationship with incidence of fruit lesions on grapefruit. The number of wind gusts =18 km/h increased with distance from the windbreak. The highest fruit canker incidence occurred in approximately the central zone of the block and the lowest incidence was found nearest windbreaks. Number of wind gusts and canker were linearly related, i.e., the greater the number of gusts, the higher the fruit disease. As the number of wind gusts increased with distance from the windbreak, incidence of unsightly wind scar also increased. These results confirm that windbreaks are a highly effective method for protection of fruit from infection by Xanthomonas citri subsp. citri, as well as physical damage from wind buffeting.