This paper describes the design and implementation of a Yield sensor for cotton strippers. The sensor is utilizing electro-optic technology. The sensor combines emitters and detectors mounted on the clean chute of the stripper. As the cotton passes through the chute, it is illuminated by the emitters. The detectors which are positioned across the chute detect the light pulses. The pulse count is relative to the volume and density of the cotton. It can then be used to estimate the mass of the cotton passing through the chute. The cotton weight is displayed on the cab indicator and also stored on a recording media, together with the GPS position of the stripper. The data can then be processed and displayed as a yield map. This technique enables growers of row cotton as well as of UNR cotton to monitor the yield of the crop for future improve of the field performance.