Common methods of fertilizer application can only meet parts of the grass growth and requires considerable labor and time.Objective of this research was to compare performance of potential sensors for the detection of optimum grass growth levels and sensor operation conditions.CCD camera with different heights and angles;and ultrasonic sensor and crop circle with different heights were used for finding optimum detection range in 3 different grass growth conditions.In order to sensor performance in actual field conditions tests were conducted with tractor static,under vibration and no traveling, and vibration with traveling conditions.The image sections were classified as grass or grassless parts by image processing and the CCD camera at 90° angle and 100 cm height showed the best fitting degree and height optimum conditions.The ultrasonic sensor had a high correlation with NDVI at 100 cm detection showing its applicability during tractor traveling condition.This study was a step for the automated grass growth mapping towards the development of autonomous mower tractor and would contribute greatly to increase the grass quality and growth,liberate the labor, and also be integrated with other management practices such as autonomous mower tractor system application based on real-time grass growth management.