3. Results
All fibre quality measures had significant associations with lint yield in both data sets, being consistently negative for fibre length and strength, but more variable for micronaire, fineness and maturity (Table 2).
3.1. Fibre length
Fig. 1 shows the negative association between HVI fibre length and yield across years for US and AUS data.
The relationship had significantly different intercepts (P < 0.001) with the same slope for each year in each country ( Table 2).
However it is clear the slope of the negative association was lower for the AUS data (−0.00028 ± 0.00017 mm/kg/ha) than US data (−0.00340 ± 0.00045 mm/kg/ha, Table 2) and there were a greater number of higher yielding genotypes with longer fibres in the AUS data.
Outliers in the AUS data with yields less than 2000 kg/ha were generally the US controls – all US Acala types.