Table 2.
Dates of measurements of normalized difference vegetation index (NDVI) and greener area (GGA) indices, presented as the calendar date, days after sowing (DAS), developmental scale (Zadoks et al., 1974), and corresponding phenological stage.
| Season | Date | DAS | Vegetation indices | Zadoks scale | Phenological stage | |
|---|---|---|---|---|---|---|
| 2017/18 | 22-February | 112 | GGA1 | 20–29 | Tillering | |
| 26-March | 144 | GGA2 | ||||
| 6-April | 153 | NDVI1 | 30 | Stem elongation | ||
| 17-April | 166 | NDVI2 | GGA3 | |||
| 17-May | 196 | NDVI3 | GGA4 | 45 | Booting | |
| 31-May | 210 | GGA5 | 65 | Anthesis | ||
| 6-June | 216 | NDVI4 | ||||
| 20-June | 230 | NDVI5 | GGA6 | 75 | Middle grain filling | |
| 2018/19 | 18-February | 74 | GGA1 | 13 | 3 leaves unfolding | |
| 5-March | 96 | GGA2 | 20–29 | Tillering | ||
| 21-March | 12 | NDVI1 | GGA3 | |||
| 3-April | 124 | NDVI2 | GGA4 | 30 | Stem elongation | |
| 26-April | 148 | NDVI3 | GGA5 | |||
| 6-May | 158 | NDVI4 | GGA6 | 45 | Booting | |
| 14-May | 166 | NDVI5 | GGA7 | 55 | Heading | |
| 24-May | 176 | GGA8 | 65 | Anthesis | ||
| 28-May | 180 | NDVI6 | ||||
| 29-May | 181 | GGA9∗ | ||||
| 11-June | 194 | GGA10∗ | 75 | Middle grain filling | ||
*Unlike the other GGA indices, which were calculated from a single image, these indices were calculated from segmented images. The methodological details of image acquisition and processing are found in the “Vegetation Indices” section of MATERIALS AND METHODS.