Three derivatives of Gossypium hirsutum race stocks were found to have measurable levels of resistance to the boll weevil when evaluated in replicated field tests.

The Texas 277 derivative gave the greatest reduction (more than 50%) in infested squares and had significantly reduced adult emergence from squares with egg punctures. Texas 1180 derivative gave approximately 30% reduction in infested squares; however, the percentage adult was significantly greater than the commercial standard. Texas 1219 derivatives appeared to be a promising source of resistance.

The mechanisms of resistance in these three race stocks have not been identified but are not related to the morphological characters that are known to be associated with boll weevil resistance.