Table 1.
Model performance for the 13 forage attributes based on full spectrum
| Variable | HSI | # LV PLSR | Calibration | Validation | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R2 | RMSE | # images | Min. | Max. | Mean | SD | R2 | RMSE | # images | Min. | Max. | Mean | SD | |||
| LMW (mg/g) | BL + PS | 8 | 0.54 | 13.90 | 131 | 22.3 | 127.4 | 53.9 | 20.4 | 0.26 | 17.60 | 64 | 23.0 | 121.3 | 54.1 | 20.3 |
| HMW (mg/g) | BL + PS | 12 | 0.68 | 19.90 | 129 | 2.4 | 167.5 | 36.2 | 35.1 | 0.63 | 21.60 | 66 | 3.1 | 144.1 | 37.1 | 35.0 |
| Sugars (mg/g) | BL + PS | 12 | 0.70 | 28.90 | 129 | 26.7 | 252.8 | 90.0 | 52.2 | 0.58 | 34.40 | 66 | 27.1 | 244.5 | 91.5 | 52.8 |
| Visual yield (%) | BL + PS | 4 | 0.43 | 2.85 | 25 | 11.4 | 26.5 | 19.9 | 3.7 | 0.12 | 3.24 | 12 | 14.6 | 25.9 | 20.3 | 3.3 |
| NDF (%) | BL + PS | 11 | 0.38 | 2.53 | 123 | 38.7 | 53.1 | 45.9 | 3.2 | 0.19 | 2.98 | 62 | 38.7 | 53.8 | 45.9 | 3.3 |
| ADF (%) | BL + PS | 16 | 0.59 | 1.39 | 123 | 21.1 | 30.2 | 25.7 | 2.2 | 0.36 | 1.68 | 62 | 21.6 | 30.2 | 25.9 | 2.1 |
| Nitrogen (%) | BL + PS | 20 | 0.86 | 0.25 | 127 | 0.4 | 4.65 | 3.2 | 0.7 | 0.70 | 0.35 | 64 | 1.6 | 4.72 | 3.21 | 0.6 |
| DOMD (% DM) | BL + PS | 9 | 0.43 | 1.36 | 120 | 60.0 | 69.4 | 65.2 | 1.8 | 0.25 | 1.50 | 61 | 61.2 | 69.2 | 65.3 | 1.7 |
| ME (MJ/kg DM) | BL + PS | 9 | 0.43 | 0.22 | 120 | 9.6 | 11.1 | 10.4 | 0.3 | 0.25 | 0.24 | 61 | 9.8 | 11.1 | 10.4 | 0.3 |
| DM (%) | BL + PS | 13 | 0.45 | 0.52 | 124 | 92.9 | 96.4 | 94.5 | 0.7 | 0.13 | 0.64 | 63 | 93.0 | 96.2 | 94.5 | 0.7 |
| Ash (%) | BL + PS | 21 | 0.70 | 0.66 | 125 | 5.7 | 12.6 | 9.8 | 1.2 | 0.50 | 0.80 | 62 | 6.5 | 12.2 | 9.9 | 1.1 |
| Ca (mg/g) | BL + PS | 6 | 0.18 | 0.97 | 127 | 1.6 | 7.9 | 4.3 | 1.1 | 0.17 | 0.91 | 60 | 2.5 | 7.2 | 4.3 | 1.0 |
| OM (%) | BL + PS | 12 | 0.62 | 0.91 | 125 | 80.7 | 89.5 | 84.6 | 1.5 | 0.43 | 1.04 | 62 | 81.2 | 88.4 | 84.6 | 1.4 |
| LMW (mg/g) | BL | 8 | 0.51 | 13.60 | 121 | 22.7 | 127.4 | 51.9 | 19.3 | 0.26 | 17.40 | 59 | 23.1 | 121.3 | 52.5 | 20.0 |
| HMW (mg/g) | BL | 13 | 0.73 | 16.90 | 121 | 2.4 | 167.5 | 32.8 | 32.5 | 0.71 | 18.50 | 59 | 3.1 | 136.2 | 34.5 | 33.8 |
| Sugars (mg/g) | BL | 12 | 0.71 | 27.00 | 119 | 26.7 | 252.8 | 85.5 | 50.1 | 0.54 | 32.80 | 61 | 27.1 | 244.5 | 85.1 | 47.8 |
| Visual yield (%) | BL | 4 | 0.42 | 2.86 | 25 | 11.4 | 26.5 | 19.9 | 3.7 | 0.05 | 3.35 | 12 | 14.6 | 25.9 | 20.3 | 3.3 |
| NDF (%) | BL | 10 | 0.35 | 2.56 | 116 | 38.7 | 53.1 | 45.7 | 3.2 | 0.14 | 3.01 | 54 | 38.7 | 53.8 | 45.5 | 3.2 |
| ADF (%) | BL | 8 | 0.34 | 1.78 | 113 | 21.1 | 30.2 | 25.6 | 2.2 | 0.41 | 1.61 | 57 | 21.6 | 30.2 | 25.8 | 2.1 |
| Nitrogen (%) | BL | 9 | 0.61 | 0.34 | 115 | 1.9 | 4.6 | 3.3 | 0.5 | 0.52 | 0.39 | 61 | 2.1 | 4.7 | 3.3 | 0.6 |
| DOMD (% DM) | BL | 9 | 0.47 | 1.27 | 112 | 60.6 | 69.4 | 65.3 | 1.7 | 0.33 | 1.44 | 54 | 61.2 | 69.2 | 65.3 | 1.7 |
| ME (MJ/kg DM) | BL | 9 | 0.47 | 0.20 | 112 | 9.7 | 11.1 | 10.4 | 0.3 | 0.33 | 0.23 | 54 | 9.8 | 11.1 | 10.4 | 0.3 |
| DM (%) | BL | 9 | 0.33 | 0.58 | 113 | 92.9 | 96.4 | 94.5 | 0.7 | 0.11 | 0.63 | 59 | 93.0 | 96.2 | 94.5 | 0.7 |
| Ash (%) | BL | 21 | 0.87 | 0.43 | 116 | 5.7 | 12.6 | 9.9 | 1.2 | 0.55 | 0.77 | 56 | 6.5 | 12.2 | 9.9 | 1.1 |
| Ca (mg/g) | BL | 5 | 0.18 | 0.96 | 117 | 1.6 | 7.9 | 4.4 | 1.0 | 0.08 | 0.93 | 55 | 3.0 | 7.2 | 4.4 | 0.9 |
| OM (%) | BL | 15 | 0.72 | 0.80 | 113 | 80.7 | 89.5 | 84.6 | 1.5 | 0.50 | 0.98 | 59 | 81.2 | 88.4 | 84.6 | 1.4 |
Models are based on the mean reflectance HSI spectra analysed by PLSR model (Blades (BL) + pseudostems (PS) and blades (BL) only; Standard Normal Variate (SNV) preprocessing