3-D Maps of Japanese Citrus Information for Precision Agriculture

Most of mandarin oranges (Citrus Unshu) are manually harvested and sorted sorted based on size, color, shape and internal qualities at cooperative grading facilities in Japan. 80% of the oranges are marketed as fresh fruits. Since higher quality oranges can be given higher prices, it is important to produce high quality fruits and to grade them properly. It is known that fruit quality in each tree is different from place to place because environmental conditions are different even in a same orchard. There are not many researches on this variability from a viewpoint of precision agriculture in Japanese orange production. In this research, the 2-D map and 3-D map were developed in order to create the visualized maps of features on color, size, sugar content, yield, canopy size, and others for optimum tree management by measuring the qualities of the harvested fruits using a mobile citrus fruit grading machine. This machine could travel in citrus orchards and measure appearance and internal qualities of fruits harvested by human in front of citrus trees. 2-D maps can show a relationship between 2 types of data. 3-D map can show the relationships among 3 features. It was observed that 2-D maps were effective for overlaying aerial images and a soil information map and that 3-D maps were effective for tree management changing with complicated environmental conditions. In conclusion, field maps using circles and cylinders were effective for tree management in Japanese agriculture.