Localised crop output measurement is the principal requirement in determining profit on a spatially variable basis. Quality of agricultural products immediately affects the market value. Therefore, quality maps should be obtained as well as yield map. In this research, a database of spatial yield and quality information was created for sweet pepper by using the mobile fruit grading robot. Then a real-time mapping method was developed from the database. Three hundred and seventy-two sweet pepper fruits harvested from 300 plants were utilised for the experiment in laboratory. Information such as plant location, harvesting time, fruit index (number of fruits from a plant), fruit size, colour, shape, defects and grade also mass was obtained. Based on these information sources, a database was established to create both a yield map and a quality map. Results indicated that the database is adequate to represent the spatial variability of yield and quality in a field as yield and quality maps, the developed mapping program is effective and practical, and that the system can be applied in real time. (c) 2004 Silsoe Research Institute. All rights reserved Published by Elsevier Ltd.