Fig. 8. Comparison of the cumulative number of irrigations calculated using the temperature–time threshold (TTT) method and the field-measured canopy temperature data compared with the average of the cumulative irrigation signals calculated using temperatures predicted by the scaled method. The data shown for the scaled method are averages using one-time-of-day temperature measurements at all times from 0815 to 2200 h CST. The 95% confidence limits are drawn around the average predicted cumulative number of irrigations. Data are from the 2001 cotton crop and the 28/452 treatment.