USING DIGITAL IMAGES FOR MEASUREMENT OF MANDARIN (Citrus reticulata) FRUITS DIAMETER DURING GROWTH

Abstract

The purpose of this work was to use digital images for measuring the equatorial diameter of mandarin fruits during growth on the tree for the construction of growth curves. The experiment was carried out in a plot (9 m x 5 m) with fruit trees (Acerola, lemon, mandarin, palms) growing naturally (Valencia, Venezuela). Two fruits during growth from the bottom crown (2.5 m high from the ground) of the tree were selected (equatorial diameter 39 mm), and a fixed reference for measurements was placed nearby. A laptop computer and a CCD digital camera, (calibrated), were used, and graphic design software. Assays were carried out during 105 days and every 4 to 5 days the fruits were photographed. The images were downloaded to computer and processed with the software CorelDRAW^® X3. The measurements of fruits in images were done using a virtual graduated rule created with the software, and with the data, growth curves were made. The behaviour of both fruits during growth was similar with coincidences in measurements (day 58: 44.25 mm; day 84: 50.50 mm). The phase 3 started at day 84, approximately, and the equatorial diameters reached at day 105 were for each fruit 48.50 y 50.75 mm. Measurements were feasible by the procedure used.