The aims of the project were: * to test various versions of SIRATAC on a commercial scale. * to provide a database of the response of cotton to damage. * to compare the response of the new varieties Siokra and DP90 with DP61. Field work consisted of large scale trials on the leased Leitch block and small plot experiments using manual disbudding to simulated pest damage. The results of these trials were integrated with data from CS16L (The response of cotton crops to damage) and CS23L (Development Officers for SIRATAC) and made available to the industry at the Australian Cotton Conference (Kelly et at 1988). Further analysis of these results has shown that the capacity of the cotton crop to compensate for early season damage depends on the yield level. At yield levels common a decade or more ago (5 to 6 bales per ha) the crop could compensate but at current yield levels (7+ bales per ha) it is unable to do so. Furthermore Siokra is more tolerant to damage than DP90. These findings have been published in a series of three papers in the Journal of Economic Entomology (Brook et a1 1992, in press) and received rave reviews from the cotton entomology community. The abstracts of these papers are attached.