Core Ideas
∙ GreenSeeker (GS) and UAV NDVI at Feekes 5 shows the most potential for in-season wheat yield estimation.
∙ Comparable accuracy of yield estimation was achieved with GS NDVI and UAV NDVI.
∙ The accuracy of yield estimation was comparable for all wheat classes and cultivars.
∙ Estimation of in-season wheat protein content remains a challenge.