Within‐Boll Yield Components of High Yielding Cotton Cultivars

Abstract

Cotton (Gossypium hirsutum L.) within‐boll yield components have changed throughout the last 30 yr of cultivar development. The question arises, how do within‐boll yield components differ in contemporary high yielding cultivars? Nine commercially available cotton cultivars were over‐seeded and hand‐thinned to 10.8 plants m−2 in 2001, 2002, and 2003. Before machine harvest, plants from 6 m of one row were removed from each plot and hand‐harvested by fruiting position. After hand‐harvest, seed cotton from each fruiting position was ginned separately. Boll number, lint mass, seed number, seed mass, seed surface area, and fiber properties were determined for each fruiting position. These data were then used for within‐boll yield component calculations. One of the top yielding cultivars in this investigation (DPL 33 B), characterized by a smaller seed mass, produced greater total seed surface area per unit of land area, but lower lint mass and fiber number per unit of seed surface area. The other two top yielding cultivars in this investigation (DPL 491 and STV 4892 BR), characterized by a larger seed mass, produced lower total seed surface area per unit of land area, but greater lint mass and fiber number per unit of seed surface area. These data indicate fiber number and lint mass per unit of seed surface area are linked to seed size, which should be considered when selecting for increased lint mass or fiber number per unit of seed surface area.

Effects of Nitrogen and Planting Seed Size on Cotton Growth, Development, and Yield

“…When grown in these environments with four N application levels the varieties of the respective seed‐size classes produced fuzzy seed that differed in mean weight (Table 2). Lint yields and mean seed size of commercial cotton varieties have varied inversely for the past 60 yr (Culp and Harrell, 1975; Harrell and Culp, 1976; Bednarz et al, 2007), apparently in response to selection for high lint percentage and lint yield. Highest lint yields were observed in these experiments when varieties were of a medium seed size.…”

“…Such a result could accrue from simple selection for high gin turnout, the fraction of lint obtained from harvested seed cotton. In fact the mean seed size of cotton varieties has been decreasing for the last 30 yr (Bednarz et al, 2007).…”

Combining ability for fiber quality parameters and within-boll yield components in intraspecific and interspecific cotton populations

“…Non-additive gene action for fiber quality traits, including fiber length, fiber strength and micronaire value, have been reported by Khan et al (1991), Baloch et al (1997) and Hassan et al (2000). Cheatham et al (2003) indicated that lint percentage and fiber strength exhibited primarily additive genetic effects, while micronaire and length exhibited primarily dominant genetic effects. The result of the half-diallel analysis showed that LP exhibited additive and dominant genetic effects, with the dominant effect being primary.…”

“…However, the negative and non-significant association between strength and LP, L/S, L/SAS, F/S, and F/SAS for interspecific F 1 cotton populations shows the complex interrelationship of fiber strength with lint yield components. It seems logical that the ultimate way to increase yield per boll is to increase the number of fibers produced, since fibers produced per seed has the greatest effect on lint yield (Bednarz et al, 2007;Rauf et al, 2007). A negative and significant correlation of UI with F/S and F/SAS shows that increasing the number of fibers borne on seeds leads to more variability in the length of fibers (Basal and Smith, 1997).…”

“…Hassan et al (2000) and Ahuja and Dhayal (2007) report a nonadditive gene action for fiber quality parameters. Cheatham et al (2003) indicate that the lint percentage and fiber strength exhibited primarily additive gene effects, while micronaire and length exhibited primarily dominant genetic effects. A number of researchers reported significant general combining ability (GCA) for basic yield components and fiber quality parameters (Green and Culp, 1990;Coyle and Smith, 1997;Basal and Turgut, 2003;Ahuja and Dhayal, 2007).…”