Several cotton lines have been identified as having resistance to Heliothis spp. which is attributed to allelochemics including flowerbud gossypol, condensed tannins, and unidentified or "X" factors. Adapted Louisiana cottons which were susceptible to damage by Heliothis spp. larvae were mated with Dr. Lukefahr's resistant lines "GT-5-A-10-15-2 X G15", "F6(M8 X T27)-l-21-6-8", and "F4(D2Sm X T254)-24-14-17 H" for the incorporation of these respective resistance traits. Heliothis spp. resistant progeny of these matings were selected, intercrossed for several cycles and resulting advanced strains were evaluated in replicated resistance trials. In these studies, the advanced strains exhibited up to a 50% reduction in feeding damage by Heliothis spp. larvae. The successful development of advanced Heliothis spp. resistant strains through these procedures suggested that each of the respective resistance mechanisms were successfully fixed and selected.

A study was conducted to obtain more information on the genetic properties associated with Heliothis resistance and flowerbud gossypol content in several advanced La. strains. These included "La. HG 126-7-2058", "La. T254-2158ne", and "La. T27-1740yp" as well as the Heliothis spp. susceptible cultivar, "Deltapine 41". The mating design was a generation means analysis which involved all possible matings between these parents. Six generations (P1, P2, Fl, F2, BCIFI, and BC2Fl) per mating were developed and planted in a replicated field trial in 1985 at Clinton, LA.