Pix is now in common use to manage vegetative growth of cotton in Australia. I presented a paper at the 1992 ACGRA Conference detailing how to evaluate potential responses to Pix. That procedure utilises regular measurements of plant height and node numbers. Plant growth is assessed on recent development, rather than using average node lengths. Since it is usually too late to obtain yield responses to Pix once a crop is already too tall, this procedure allows problem situations to be diagnosed before excessive vegetative growth occurs. The results of that study are summarised in Figure 1. They show that internode increases of less than 5.5 cm lead to no response or even negative yield responses to Pix.