The influence of maturity ratio on micronaire can be seen in Fig. 3. This multiple linear regression compares both FD methods and displays predicted FDmic at three different maturity ratio values, 0.65 considered immature, 0.85 intermediate and 1.05 mature fibre. It is clear that FDmic overestimates the true value due to differences in maturity ratio affected by genotype or the environment. Cramner (2004) reported that most accurate value of FPS was in a more matured fibre. Our data show that the difference in the variability is indeed smaller when the maturity ratio was higher, however the variability still exists.