Effects of different hanging methods of RFID tags on reading rate in fruit tree

RFID plays an appropriate role for single fruit tree identification, however its position of hanging on the tree affects the reading rate significantly. In this study, test environment was established in an apple orchard of Shandong province. The times of successful reading was obtained according to four treatment conditions, which were different distance between RFID tags and reader antennas (condition1), different vertical hanging height on the fruit trees (condition2), different horizontal hanging distance on the fruit trees (condition3) and different shades in the front of tags (condition4). The results showed that the times of successful reading reduced gradually with the increasing distance between RFID tags and reader antennas. The reading effect was sound in the range of 2.0 m, but there was a marked drop with 50% reading rate in the ranges of 3.0 m and 3.5 m. The decline in reading rate was shown in condition2 and condition3, as the distance between RFID tags and plane center line of reader antennas increased. In condition4, the times of successful reading with branch shade was higher than the times with fruit shades, but lower than the times of leaf shades. Based on the results, the optimum hanging position was: the tags hung on the side branch near the row space, which was 1.2-1.4 m higher than the ground and faced to the row space without shades.