Table 4.
Selected weather conditions prevailing at the time of thermal image capture (A) and some daily average values (B)
| Date | year-month-day | 2011-07-11 | 2011-07-26 | 2011-08-02 | 2011-08-12 | 2011-08-16 | 2011-09-15 |
|---|---|---|---|---|---|---|---|
| Time | hh:mm:ss | 17:45:38 | 16:45:38 | 17:25:38 | 17:25:38 | 17:25:38 | 14:25:38 |
| Days after sowing | days | 81 | 96 | 103 | 113 | 117 | 147 |
| Thermal timea | °C days | 612 | 727 | 793 | 893 | 940 | 1275 |
| A at time of thermal capture | |||||||
| Air temperature (TA) | °C | 25.95 | 24.40 | 27.52 | 24.40 | 24.01 | 21.71 |
| Relative humidity (rH) | % | 51.25 | 37.75 | 53.25 | 56.25 | 69.75 | 56.25 |
| Dew point | °C | 15.1 | 9.1 | 17.2 | 15.1 | 18.2 | 12.6 |
| Wind speed | m s−1 | 0.93 | 1.3 | 0.74 | 1.3 | 0.56 | 0.93 |
| Gust speed | m s−1 | 2.23 | 3.15 | 1.86 | 3.53 | 2.23 | 2.41 |
| Soil temperature in 5 cm depth (TS) | °C | 20.63 | 17.34 | 19.20 | 18.70 | 20.15 | 17.32 |
| Vapour pressure deficit (VPDair)b | kPa | 0.62 | 0.76 | 0.62 | 0.54 | 0.37 | 0.50 |
| Photosynthetically active radiation (PAR)c | μmol s−1 m−2 | 1422 | 1082 | ndd | 1611 | 1043 | nd |
| B based on daily data | |||||||
| Maximum air temperature (TMAX) | °C | 27.3 | 25.0 | 28.1 | 26.1 | 26.1 | 21.9 |
| Evapotranspiration (ETO- Penman)e | mm day−1 | 4 | 3.1 | 3.7 | 4.5 | 3.1 | 2.1 |
| Radiatione | kWh m−2 | 7.0 | 5.4 | 6.5 | 5.5 | 5.4 | 4.6 |
| Sun hourse | h | 12 | 9.0 | 11.0 | 11.0 | 10 | 9.0 |
| 7 day cumulated precipitation | mm | 40.6 | 37.0 | 30.4 | 36.0 | 22.8 | 24.8 |
| Total cumulated precipitation | mm | 230.2 | 329.8 | 360.2 | 415.4 | 434.4 | 508.0 |
aTT = ∑if ≥ 0((Tmax + Tmin)/2)- Tbase, Tbase of 8°C, bcalculated according equation, cmeasured with a line quantum sensor, dnot detected, eprovided by the meteorological service (LTZ, Baden-Württemberg, Germany).