No abstract

Radically enhancing of employed technologies on the growing of agricultural crops in Uzbekistan and quality of varieties has become one of the major challenges in the state priority today. Because, in the example of cotton plant as the principle crop, the republic is remaining far behind on cotton raw productivity -12th , and on cotton fiber productivity-29th than cotton producing countries. At this term, the state is a head reformer extending all scientific-technical and organizing measurements for the development of this field. The results on the study of seed stock cotton varieties’ cultivation for two years (2018, 2019) in the Burkhon farm, Navoiy division of Oqqorgon district, Tashkent region were presented in this paper. Planting quality, influences of seeds on the seed sprouting period, field germination of seed stocks, optimal seed stock expenditure, optimal seedling density, plants’ development and dynamics of yield components setting were studied in the field observations. It was identified that the used drill has planted at minimum, from 9 and maximum, up to 29 seeds per 1 m of a row. Coefficient of variation, according to the outcome of statistical analysis on the determination of difference between these two indexes has made of 29.7%. Field germination, height of plants, instability on the plants’ boll numbers and share of contamination in the variety traits of varieties were also analyzed and the necessary recommendations on new innovative ideas and technologies for improving of cotton seed production in grooving varieties and producing of seed stocks were given. KEYWORDS: Cotton, seed, germination, seed stock, technology, sprouts, variety, Sultan, S-6524.

One of the important problems in cotton breeding is the creation of high-yielding, fast-maturing varieties with high fiber yield and quality and their wide use in production. Due to the increase in the number of people on earth and the reduction of irrigated arable land, it is important to get a high quality harvest suitable for different soil and climate regions without expanding the arable land. This research intended to study the variability of the observed characters in the phenotype of the cotton plant during the selection of four F2-F4 hybrid combinations in the conditions of Tashkent, Fergana and Kashkadarya regions. During the research experiments, classical genetic-selection methods of cotton, hybridological analysis methods, comparative morphology, phenological observations and genetic-statistical analysis methods were used. The results showed that the average indicators of this sign were approximately the same in Fergana and Kashkadarya regions, accounted for 116.5 and 117 days, which was 12 days shorter than the growth period of this hybrid in Tashkent region. Similarly, insignificant changes of the above combinations were also observed in the experiments of 2019 and 2020. It was found that in F2 [(F8 L-247 x S-484) x F15 L-248], the fiber length variation was not significantly affected by the environment, the variation ranged from 0.04 inches to 0.07 inches.

The hybrids of medium-fiber cotton were assessed in terms of fiber quality in the Tashkent, Fergana and Kashkadarya regions of the Republic of Uzbekistan. 4 hybrid combinations of different genetic origin were tested. The analysis of the influence of the genotype and the environment on the manifestation of the qualitative parameters of the fiber (length, specific breaking load, micronaire) was carried out. High values were found in hybrids involving the wild species G. trilobum Skovsted and the ruderal form G. Harknessii Brand. as well as varieties Bukhara-6. As a result of three years of experiments, it was found that the genotype and unaccounted factors influence the variability of the fiber length to a greater extent. The genotype rather than the environment significantly affects the specific breaking load of the fiber. The variability of the micronaire fiber is more dependent on environmental conditions.