Since the 1960's, upland cotton (Gossypium hirsutum L.) production in southern Tamaulipas region of Mexico has declined dramatically due to increased insecticide costs for control of the bollweevil (Anthomomas grandis Boheman), bollworm [Helicoverpa zea (Boddie)], and tobacco budworm [Heliothis virescens (F.)], as well as lower prices for lint. This two-year study was conducted to evaluate eight experimental strains and two locally grown cultivars for lint yield, yield components, and fiber quality. Cultivars and strains differed across the two years for days to first bloom and first open boll, first harvest and total lint yield, earliness, boll weight, and lint quality. Traits that were significantly associated with total lint yield included first harvest (r=0.94, P<0.01), days to first bloom (r=0.53, P<0.01), days to first open boll (r=0.60, P<0.01), and earliness (r=0.68, P<0.01). The close relationships of first harvest and earliness with total lint yield indicate the potential advantages of early maturing cottons under this tropical environment of wet and dry seasons. From these results, it appears that several of the advanced experimental strains, which are generally earlier in fruiting and crop maturity, may be able to reduce production costs and offset lower returns in southern Tamaulipas.