1. CRC for Sustainable Cotton Production, Department of Agricultural Chemistry and Soil Science, University of Sydney, Sydney 2006, Australia; CSIRO Division of Plant Industry, North Ryde, NSW 2113, Australia; CSIRO Division of Plant Industry, Canberra, ACT 2601, Australia; Department of Natural Resources, Toowoomba, QLD 4350, Australia; and Centre for Pesticide Application Safety, Gatton College, University of Queensland, Gatton, QLD 4343, Australia