TABLE 4.
Evaluation of model performance on the test set for single-day models (trained on data at late booting stage) and 3D-CNN.
Model | Fold | RMSE (Mg/ha) | MBE (Mg/ha) | MAE (Mg/ha) | R 2 |
Null | A | 0.93 | −0.50 | 0.79 | n.d. |
B | 0.75 | 0.08 | 0.57 | n.d. | |
C | 0.80 | 0.30 | 0.60 | n.d. | |
D | 0.83 | 0.13 | 0.62 | n.d. | |
Mean | 0.83 | 0.00 | 0.65 | n.d. | |
Linear | A | 1.06 | −0.78 | 0.93 | 0.17 |
B | 0.70 | 0.07 | 0.51 | 0.18 | |
C | 0.94 | 0.59 | 0.70 | 0.15 | |
D | 0.83 | 0.10 | 0.63 | 0.04 | |
Mean | 0.88 | −0.01 | 0.69 | 0.14 | |
XGBoost | A | 0.88 | −0.45 | 0.72 | 0.11 |
B | 0.74 | −0.02 | 0.53 | 0.19 | |
C | 0.83 | 0.50 | 0.61 | 0.22 | |
D | 0.83 | 0.11 | 0.63 | 0.04 | |
Mean | 0.82 | 0.04 | 0.63 | 0.14 | |
2D-CNN | A | 0.73 | −0.19 | 0.57 | 0.18 |
B | 0.68 | 0.13 | 0.47 | 0.29 | |
C | 0.63 | 0.02 | 0.45 | 0.30 | |
D | 0.84 | 0.28 | 0.62 | 0.10 | |
Mean | 0.72* | 0.06* | 0.53 | 0.22 | |
3D-CNN | A | 0.80 | −0.37 | 0.67 | 0.08 |
B | 0.67 | 0.17 | 0.48 | 0.27 | |
C | 0.77 | −0.24 | 0.61 | 0.37 | |
D | 0.90 | 0.45 | 0.67 | 0.06 | |
Mean | 0.79 | 0.00 | 0.61 | 0.20 |
*Indicates significant difference in mean value between 2D-CNN and linear model only (p ≤ 0.05; one-way ANOVA).
RMSE, root mean squared error; MBE, mean bias error; MAE, mean absolute error;R2, coefficient of determination. n.d., not defined (observed ∼ predicted yield is a vertical line for the null model).