Table 4.

Coefficient of determination and RMSE (from repeated 10-fold cross-validation) for linear regressions between crop traits and vegetation indices calculated from UAV and ground-based data acquired on the last 4 acquisition dates (from 62 to 99 DAP). Only indices with the best prediction performance for both datasets are presented (the complete results are shown in the Table A1).

Traits	UAV Measurements
	Vegetation Index	R2	RMSE 1
Leaf chlorophyll	MTCI	0.91	2.31
Leaf area index	TCARI	0.56	0.68
Canopy chlorophyll	CIg	0.81	0.201
Ground cover	NDVI	0.90	0.037
	Ground-Based Measurements
Leaf chlorophyll	TCARI/OSAVIre	0.78	3.52
Leaf area index	OSAVI	0.58	0.63
Canopy chlorophyll	CIg	0.83	0.194
Ground cover	OSAVI	0.92	0.033

¹ RMSE values with same units of corresponding crop properties, i.e., µg·cm⁻², m²·m⁻² and g·m⁻² for leaf chlorophyll, leaf area index and canopy chlorophyll, respectively.