Fig. 5. Correlation coefficients (r) obtained between spatial yield data and hyperspectral indices as function of time. The best correlation coefficient for any index is labeled MAX compared with indices (a) NDVI, RDVI, and MTVI1; (b) MCARI, TCARI, and OSAVI; (c) red edge parameters _p, _o, and R_s; and (d) water indices PWI, mNDWI, mSRWI.