Aims: (i) To evaluate the pest resistance of cotton cultivars bearing different combinations of morphological and allelochemical resistance factors in field experiments. (ii) To investigate the mechanisms of any pest resistance (principally to Helicoverpa or mites) identified in the field using biological and chemical assays to better focus future breeding efforts and identify mechanisms suitable for genetic engineering of cotton. (iii) To provide an experimental protocol for field testing of genetically engineered culti.vars being developed by Division of Plant Industry.