A study was conducted to evaluate the effects of foliar applications of Chaperone on production characteristics of first-position bolls in rain-fed grown cotton. The study was conducted at a commercial farm in Nueces Co., TX. Production management practices were entirely controlled by the farmer. Cotton cultivar FiberMax 832LL was planted on April 1, 2005 to a plant population of 50,000 in 30' row spacing. The 2005 growing season started with good initial soil moisture conditions. Rainfall amounts during phenological stages were as follows: 1.8” from planting to first square stage, 2.0” from first square to first bloom, 2.7” from first bloom to first open boll, and 0.8 from first open boll to harvest. Rainfall accumulated from first bloom to first open boll, however, occurred very late in this stage, causing cotton to undergo severe water deficits during most of the boll growth stage. Treatments were as follows: single application of 5 oz/A at early bloom (EB), single application of 5 oz/A at mid bloom (MB), double application of 5 oz/A (at EB and MB), single application of 10 oz/A at EB, single application of 10 oz/A at MB, and the untreated check. The experimental layout consisted of a randomized complete block design with four replications. At the time of early bloom application, plants had 19 main-stem nodes, first position bloom was at main-stem node 9, and the first sympodium was at main-stem node 7, while at the time of mid bloom application (2 weeks after EB), plants had 20 main-stem nodes and the first-position bloom was at node 14. At both application times, 20 plants were tagged in all plots to mark the sympodium with the first-position bloom. After defoliation, first-positon bolls (whole bolls with burrs) produced by 9 consecutive sympodia in all 20 tagged plants were harvested and grouped by sympodium. In untreated plants and plants treated at early bloom, these 9 sympodia harvested corresponded to two sympodia below the tag and 7 above the tag, while in plants treated at mid bloom the 9 sympodia corresponded to 7 sympodia below the tag and two above the tag. This procedure allowed the comparison of first-position bolls of similar age across all treatments. Bolls grouped by sympodium were ginned after counting the number of bolls and measuring seedcotton mass. Ginned seeds were acid-delinted, and the number and weight of good and vane seeds were obtained. Chaperone, in particular, the higher rate and the mid bloom application, enhanced both the production of good seeds per boll and the average seed mass, but the latter to a lesser extent.