Table 2.
Maize yield estimation at vegetative stage by different model during Kharif 2020 and 2021.
| Model | Model equation | Model performance during calibration | Model performance during validation | Estimated yield (kg/ha) | Observed yield (kg/ha) | Percentage deviation (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R 2 | RMSE | nRMSE | RMSE | nRMSE | 2020 | 2021 | 2020 | 2021 | 2020 | 2021 | ||
| SMLR | y = 143.6 + 141.97*time + 5.16*Z571 + 2.1*Z461 | 0.93 | 258.5 | 16.83 | 703.5 | 21.05 | 4734.5 | 4682.9 | 3666.5 | 3780.3 | 29.13 | 23.88 |
| PCA-SMLR | y=-206.82 + 134.55*time + 329.5* PC4 -210.3*PC5 | 0.90 | 313.9 | 20.44 | 579.2 | 17.33 | 4644.4 | 4650.5 | 3666.5 | 3780.3 | 26.67 | 23.02 |
| LASSO | y=-669.2 + 123.85*time + 12.95* Z11 + 0.14*Z231 + 0.27*Z461 + 1.3*Z471 + 1.5*Z561 + 1.7*Z571 | 0.94 | 259.7 | 16.91 | 392.2 | 11.74 | 4085.6 | 4263.9 | 3666.5 | 3780.3 | 11.43 | 12.79 |
| Elastic Net | y = 310.6 + 95.5*time + 0.4*Z31 + 0.02*Z351 + 0.47 *Z361 + 0.5*Z461 + 1.06*Z471 + 0.76*Z561 | 0.95 | 256.5 | 16.70 | 344.9 | 10.32 | 3990.2 | 4082.8 | 3666.5 | 3780.3 | 8.83 | 8.00 |