Crop boll development was studied in Paymaster 404 grown with preplant plus one summer irrigation (PPI) and under full irrigation (FI). The length of the crop boll setting period was 28 and 42 days, respectively, for the PP1 and FI treatments. Boll size averaged 4.3 g seedcotton in both treatments but lint yield was 731 and 969 kg/ha in PPI and FI, respectively. Boll period (BP) in the FI treatment averaged 5 percent longer than in the PPI treatment for bolls initiated on the same days. For these same bolls canopy temperature in the Fl treatment averaged 8 percent less than in the PP1 treatment. Average crop fiber properties from the bulk harvest included micronaire values of 3.8 and 2.9, fiber length was 25.1 and 25.4 mm, and fiber strength was 24.5 and 24.0 g/tex, respectively, for PPI and FI treatments.

Immature bolls at crop termination (occurrence of first freezing temperature) were visually rated in four categories (IBCI) with IBC I bolls being completely closed and the most immature, and IBC 4 bolls being open and the most mature. The average maturity percentage of IBC 1, IBC 2, IBC 3, and IBC 4 was 75, 82, 88, and 97. Thus, a boll could complete 75 percent (IBC 1) of its BP and not open when development is terminated. Average boll sizes for the respective IBCI were 2.00, 2.46, 3.34, and 4.00 g seedcotton.