This study was conducted to determine comparision effectiveness of Arduino based Ultrasonic Sensor and Image analysis techniques for canopy volume measurements in different kinds of Citrus (Mandarin, Orange, Lemon, and Grapefruit) trees. In this investigation, the parameter measurements were taken on 15 different trees of each citrus species, where grown commercially produced in groves of Yenice distinct of Mersin province in Turkey. Measured values placed in Albrigo's prolate spheroid formula and canopy volumes of each tree has been calculated by using this formula. As a result of this investigation, regression coefficients were found approximately 15% better in ultrasonic canopy volume measurements than image processing technique canopy volume measurements. So, it was found that the ultrasonic measurement technique is superior against to Image Processing method for determining tree canopy volumes. In addition, statistical analysis showed that Ultrasonic and Image Processing measurement techniques can also be used for calculation of tree canopy volumes and the tree canopy volume index safely too.