FDA second experiment was conducted to determine the utility of FD in maintaining yield while simultaneously improving fineness.Contrasting FD sister lines, CSX2194 and CSX2590, were crossedwith two high micrnaire (>4.5) lines CSX5264 and CSX3369 to form four populations. These lines were chosen because their pedigree which are prone to high micronaire, such as Sicot 72 and CSX1303. The high FD parent populations were 10227(CSX2590 × CSX5264) and 10228 (CSX2590 × CSX3369), while the low FD parent generated populations 10229 (CSX2194 × CSX5264)and 10230 (CSX2194 × CSX3369). These crosses were performed in the glasshouse; seed from single F2 plants were planted in the fieldas F3 progeny rows in 2010 with 48 lines per population.