Fuente: Wipo "precision farming" Method and corresponding system for estimating crop yield from vegetation index data. At least one multispectral image (201) including a field is obtained. The part of the multispectral image (201) that represents the agricultural field (301) is delineated, and vegetation indices for locations within the agricultural field (301) are derived from the multispectral image (201). Samples of actual yield data representing yield measurements for locations within the agricultural field (301) are obtained as measured by a yield monitor on a combine harvester (208) used to harvest selected areas of the agricultural field (301). By correlating the vegetation indices with the yield data, a relationship between respective vegetation index values and corresponding absolute yield estimates is determined. The determined relationship can be used to obtain estimates of actual yield from different parts of the field, and this information can be used to identify field maintenance needs, fertilization rates, and more.