Resistance of Cotton Strains with High Gossypol Content to Heliothis Spp.12

Abstract

Experimental lines of Upland cotton, Gossypium hirsutum (L.), with a high gossypol content were evaluated against the bollworm, Heliothis zea (Boddie), and the tobacco budworm, H. virescens (F.), in laboratory and cage tests. Line XG-15 (average content of gossypol 1.7% dry weight basis) had significantly reduced populations of tobacco budworms in a large replicated field-cage test. Bioassays with lyophilized cotton square tissue incorporated in larval diet gave reliable estimates of the resistance of experimental lines to both species of Heliothis.