The growth, flowering, square, and boll formation of the cotton plant are significantly affected by sowing time and fruiting distributions. This study was carried out in order to determine the effect of sowing time, varieties and boll distribution on fiber yield and fiber quality of cotton, under the GAP region ecological conditions of Türkiye during 2017 and 2018 cotton growing seasons. In this study, Candia and Lima cotton varieties were used as plant material. Cotton seeds were sown on 5 May (normal sowing) and 10 June (late sowing) using a pneumatic seeder in both years. In the study, the number of bolls (per plant -1 ), yield per plant (g plant -1 ), boll weight (g), ginning outturn (%), holocellulose, cellulose, scan viscosity, and polymerization degree were studied. According to the research, the number of bolls, boll weight, and fiber yield were higher in normal planting than in late planting. The low positional sympodial branch (1-5 fruit branches) boll position was better in the number of bolls, and the middle positional sympodial branch (6-10 fruit branches) was better in boll weight compared to other positions. The fiber yield obtained in a low positional sympodial branch (1-5 fruit branches) and middle positional sympodial branch (6-10 fruit branches) positions was higher than the upper positional sympodial branch position (11 and higher fruit branches). The effects of sowing times and cultivars on cellulose and holocellulose rations were statistically insignificant. The cellulose ratio (94.40) obtained in the upper positional sympodial branch position (11 and higher fruit branches) in the first year was higher than the other sympodial positions, while the effect of the boll position was statistically insignificant in the second year of the experiment. In conclusion, the planting time had a significant effect on boll positions and fiber quality of cotton. Late sowing had negative impact on boll maturation, cellulose synthesis, yield and fiber quality. Hence, the delay in cotton planting caused a decrease in yield; so, cotton should be sown as early as possible in the region.