Agronomic performance and fiber quality of the new cotton varieties Tiara and Melani

The aim of this research was to study the productive potential and to evaluate the fiber technological properties of the new cotton varieties Tiara and Melani, compared to the standard cultivars. These varieties were studied in competitive varietal tri -als conducted in 2017-2019, in the experimental field of the Field Crops Institute in Chirpan. In the IASAS system, the Tiara and Melani varieties were tested in 2019-2020. They were approved as new varieties in 2021. Both varieties were obtained by remote hybridization and belong to the Gossypium hirsutum L. species. Tiara and Melani are early and productive varieties, in terms of seed cotton yield, on average for three years, they surpassed the cultivar Chirpan-539 (standard for productivity) by 8.1% and 6.5%, respectively. According to IASAS data, in seed cotton yield, 2809 kg/ha for Tiara and 2784 kg/ha for Melani, on average for two years, they equalized with the cultivar Chirpan-539 and outperformed the cultivar Avangard-264. In terms of fiber yield (1141 kg/ha and 1066 kg/ha) Tiara variety exceeded the two standard cultivars, Melani variety surpassed the cultivar Avangard-264 and leveled with the cultivar Chirpan-539. These varieties had a number of valuable fiber technologi-cal qualities and in some respects exceeded the two standard cultivars or equalized with the Avangard-264. The Tiara variety showed better agronomic performance than the Melani variety, achieving higher fiber yield, as a result of higher lint percent-age. The Melani variety had better fiber technological qualities than the Tiara variety. Compared to the standard cultivars, the Melani variety was characterized by a better spinning, consistency index (SCI), lower micronaire, greater strength and better spectroscopy with reflection of the difference RD. This variety showed a better combination of the agronomic indicators with the fiber technological qualities than the Avangard-264, a standard for fiber quality. The results obtained define the new cotton varieties as a very good combination of earliness, productivity and fiber quality. This makes them very valuable for the cotton production and breeding programs with cotton.