Drought is a common abiotic stress that considerably limits crop production. The objective of this study is to explore the influence of water deficiency on the yield, physiologic and metabolomic attributes in upland cotton cultivars (Gossypium hirsutum L). Cotton cultivars, 'Ishonch' and 'Tashkent-6' were selected to study the relationships among their physiologic, metabolomic and yield attributes during water deficiency. Deficit irrigation was designed by modifying the traditional watering protocol to reduce water use. Results indicate that cotton cultivars respond differently to water deficit stress. Water deficit significantly influenced plant height, the number of internodes, and sympodial branches in both cultivars. However, yield components such as the number of bolls, boll seed, lint mass, and individual plant yield were significantly reduced only in 'Tashkent-6'. The leaf area decreased and the specific leaf weight increased in 'Ishonch' under deficit irrigation conditions. However, 'Tashkent-6' demonstrated significant water loss compared to 'Ishonch', and both cultivars showed reduced transpiration rates. Untargeted metabolite profiles of leaves showed clear separation in 'Ishonch', but not in 'Tashkent-6' under deficit irrigation compared to full irrigation. The individual metabolites such as proline and galactinol showed strong association with yield under water deficit stress. Moreover, this study indicates that leaf area and transpiration intensity influence yield during water deficiency. In summary, the correlation among morpho-physiologic, metabolic, and yield components significantly varied between the two cultivars under water deficiency. The flowering stage was sensitive to water stress for both cultivars. The direct relationship between physiology, metabolism, and yield may be a useful selection criterion for determining candidate parents for cotton drought tolerance breeding.

The spatial distribution of cotton fields is primary information for national farm management, the agricultural economy and the textile industry. Therefore, accurate cotton information at the regional scale is required with a rapid increase due to the chance provided by the huge amounts of satellite images accumulated in recent decades. Research has started to introduce the phenology characteristics shown at special growth phases of cotton but frequently focuses on limited vegetation indices with less consideration on the whole growth period. In this paper, we investigated a set of phenological and time-series features with optimization depending on each feature permutation’s importance and redundancy, followed by its performance evaluation through the cotton extraction using the Random Forest (RF) classifier. Three sets of 31 features are involved: (1) phenological features were determined by the biophysical and biochemical characteristics in the spectral space of cotton during each of its five distinctive phenological stages, which were identified from 2307 representative cotton samples using 21,237 Sentinel-2 images; (2) three typical vegetation indices were functionalized into time-series features by harmonic analysis; (3) three terrain factors were derived from the digital elevation model. Our analysis of feature determination revealed that the most valuable discriminators for cotton involve the boll opening stage and harmonic coefficients. Moreover, both qualitative and quantitative validation were performed to evaluate the retrieval of the optimized features-based cotton information. Visual examination of the map exhibited high spatial consistency and accurate delineation of the cotton field. Quantitative comparison indicates that classification of RF-coupled optimized features achieves improved overall accuracy 5.53% higher than that which works with either the limited vegetation indices. Compared with all 31 features, the optimized features realized greater identification accuracy while using only about half the number of features. Compared with test samples, the cotton map achieved an overall accuracy greater than 98% and a kappa more than 0.96. Further comparison of the cotton map area at the county-level showed a high level of consistency with the National Bureau of Statistics data from 2020, with R2 over 0.96, RMSE no more than 14.62 Kha and RRMSE less than 17.78%.

This article deals with the biochemical characteristics of varieties of Saint Mary's Thistle such as Panacea, Debut and Samaryanka. Based on the studies, it was found that the highest oil content was found in the species Debut (26%). The lowest oil content was observed in the variety Samaryanka (19%). The highest protein content and the sum of total amino acids in the seeds of St. Mary's Thistle varieties were found in the variety Debut (131.1), and the lowest indication was observed in the species Samaryanka (79.2). By the number of replaceable amino acids existing in the seeds of the species of St. Mary's Thistle, it was found in the Varieties Debut (126.3), and the lowest indication was observed in the variety Samaryanka (112). Based on the results of studies and the noted biochemical characteristics and varietal differences of the St. Mary's Thistle, the possibility and expediency of expanding the crops of this species in the soil and climatic conditions of the Khorezm region are suggested. The research was conducted 2017-2019 y.

No abstract

Presowing treatment of cotton seeds with a physical factor (low-frequency electromagnetic field - LF EMF) and a chemical compound (glycyrrhizic acid - GzA) and sowing them under conditions of optimal and limited water supply showed that different varieties of cotton, depending on their biological peculiarities and the method of seed treatment, had different parameters of water exchange in plants. The experiments were carried out in laboratory, greenhouse, lysimetric and field conditions, the indicators of the electrical resistance of leaf tissues (ERLT) of cotton plants depended on the conditions of water supply. According to this indicator, the varieties Ishonch, Gulbahor-2 and Navbahor-2 showed greater resistance to soil moisture deficiency, in comparison with the variety Tashkent-6. The plant varieties from seeds, treated with LF EMF and GzA, to a greater or lesser extent, are in the range with the lowest ERLT values, in comparison with the varieties from untreated seeds.