The use of modern technology in agricultural industries is important among others to increase yield and improve effeciency. For this reasons, on 28th of December 2009, a meeting between Pubber Industry Smallholers Development Authority (RISDA) Perak and UTem was conducted to find the possiblilities of doing research collaboration to improve the performance and service provided by RISDA. As a result. RISDA has presented some of their practical problems that they are currently facing. One of the problem is that the process to evaluate the subsidy application takes too much timr, due to manual measurement, data collection and data transfer. In order to evaluate the performance of the applications plantation, RISDA's office need to measure the diameter/circumference of 10% of the number of rubber trees. Currently, they measure the circumference of the tree manually into a PC before submitting it in to the headquaters to analyse the data. fro this reason, this project proposed a diameter and circumference measurement technique that could increase the throughtput of the measurement while ensuring good accuracy and repeatabilty. The proposed method uses obstacle detection results from an array of infrared sensors. The sensors are arranged at a fixed distance between each other so that the number of sensors that detect obstacle represents the estimate diameter of the tree. The circumference of the tree is calculated indirectly using the diameter measurement.