Wind damage study and control on citric fruits

Abstract

A huge proportion of the citric production is discarded from exportation quality with large economic losses. The principal reason is the damage associated to the wind named “rameado”. Young fruit with less than 1cm dimension can be stressed by the leaves movement. The leaves produce small injuries on the fruit peel, which increase when the fruit increase. From particular observation, it is common find a damaged fruit below a leaf. Field measurements were made with ultrasonic anemometer YOUNG model 81000, with a frequency sampling of 10Hz. The anemometers were installed in a tower with a tree height. Measurements in the orchard shows very low wind velocities with 10 minutes mean values lower than 2.2m/s in the greater part of the time. Threshold values between 5m/s and 6m/s are quoted. Then the damage must be linked to the turbulence structure of the flow inside the orchard. Turbulence longitudinal integral scales, as large as 10m are obtained, then greater than the tree. Small scale parameter as high as 1615 was estimated.