Institute of field crops - Chirpan, 6200, Chirpan, Bulgaria
Резюме
Four white cotton lines having naked seeds – Nos. 81, 84, 88 and 93 and two
brown lines also possessing naked seeds – Nos. 105 and 106 were included in the
competition test variety trial carried out during the period 2014-2017 in the Field
Crops Institute in Chirpan. The aim of the study was to explore their productive
and qualitative capabilities with a view to their effective use in breeding programs
and as direct varieties. It was found that lines Nos. 81, 84, 88 and 93 were lower
productive than the standard cultivar Chirpan-539 and they have realized 81.8 to
89.6 % of its seed cotton yield. They had a smaller boll by 0.1-0.3 g and a lower
lint percentage by 0.8-1.7 %. Lines Nos. 81, 84 and 88 showed by 0.6 - 1.2 mm
longer fiber than that of the standard. The highest breeding value was found for the
line 88, which was the most productive and had the longest fiber. Lines Nos. 105
and 106 combine two exceptional features - naked seeds and natural colored light
brown fiber. They were very early and matured simultaneously with the standard
cultivar. In seed cotton yield, they were close to the standard achieving 91.9-96.7 %
of its yield. They were inferior to the standard in fiber length - by 1.5 mm and in lint
percentage - by 2.6-3.4 %, typical of the colored cotton. All studied lines possess
breeding value because of their naked seeds. Brown line No. 106 in seed cotton
yield was inferior very little to the white standard – the cultivar „Chirpan-539” and could be presented for state variety testing in the Executive Agency for Variety
Testing and Seed Control network for its validation as a variety.
