Compared to conventional 1 m spacings, UNR did not mature earlier in Australian systems, because fruiting site development was slowed in response to early plant competition impeding the opportunity for early fruit maturity. This response occurred much earlier and much more often than was previously thought. Yield however, was marginally higher in UNR (although highly variable) and this was achieved by having more bolls per area from the increased population. Bolls were smaller but the greater number of bolls in UNR compensated this. The use of Pix and changes in early season crop management for water and nutrition did not improve UNR yields. Primary fibre quality properties were unaffected in UNR systems, although grades can be reduced with stripper harvesters.