Table 2. Growing condition variables and data range during the field trial data collection period from 1983 to 2008

Growing condition variable	Low	High	Mean	CV
Accumulated temperature within temperature range1)
0°C to 25°C	3,181	4,838	4,334	0.12
0°C to 30°C	3,181	5,037	4,387	0.12
Above 0°C	3,181	5,051	4,387	0.12
5°C to 25°C	2,003	3,383	2,954	0.14
5°C to 30°C	2,003	3,582	3,006	0.15
Above 5°C	2,003	3,596	3,006	0.15
10°C to 25°C	1,096	2,178	1,837	0.18
10°C to 30°C	1,096	2,377	1,889	0.19
Above 10°C	1,096	2,391	1,889	0.19
Sunshine duration (hr)
0°C to 25°C	1,294	1,892	1,586	0.11
5°C to 25°C	955	1,495	1,291	0.12
Duration of temperature (day)
0°C to 25°C	246	304	275	0.05
5°C to 25°C	193	242	220	0.05
Daily mean temperature > 25°C
Days > 25°C	Na	63	23	0.65
Accumulated temperature > 25°C	Na	1801	659	0.65
January temperature (°C)
Daily mean	−8.9	1.1	−3.4	−0.76
Daily low	−13.7	−3.0	−8.2	−0.34
Rain day (day)
Over 0 mm	80	150	103	0.15
Over 5 mm	30	73	48	0.20
Precipitation amount (mm)
Accumulated rainfall (over 0 mm)	841	2,482	1,347	0.27
Accumulated rainfall (over 5 mm)	752	2,384	1,257	0.29
Soil property2)
Clay content (%)	0.2	26.8	14.3	0.45
Drainage (nominal)	3.4	6.5	5.2	0.09

The base temperature was 5°C.
Jitter-transformation applied values.
CV, coefficient of variation.