Calculate growing degree days (GDD) accumulation to predict crop development stages, flowering, and harvest dates.
Wheat (base 0°C). Tmax 22°C, Tmin 8°C.
At 15 GDD/day, wheat needs ~60 days to reach flowering (900 GDD).
GDD = (Daily max + Daily min) ÷ 2 − Base temperature. Base temps: wheat 0°C, canola 5°C, maize 10°C, cotton 15°C.
Wheat: 100 emergence, 600-800 stem elongation, 800-1,000 flowering, 1,200-1,500 maturity. Canola: 200 emergence, 500 flowering, 1,000 maturity.
Wheat/barley/canola: 0°C. Sunflowers: 5°C. Maize/sorghum/soybeans: 10°C. Cotton: 15°C. Potatoes: 5°C.
Plant when soil temperature at seeding depth reaches 5-10°C for cereals. Use GDD to match variety maturity to your season length and avoid frost at flowering.