Water Use Efficiency of Long Staple Cotton Varieties in Southern Zone of Uzbekistan

Previous research established field capacity (Fc) based irrigation scheduling for upland cotton (Gossypium hirsutum L.) varieties in Uzbekistan. In this paper, the irrigation scheduling Fc for two long staple cotton (Gossypium barbadense L.) varieties and its effect on seed-lint yield and irrigation water use efficiency and water consumption of plants were reported. The field experiments were conducted in the condition of takyr soils with mechanical composition of silt loam in southern zone of Uzbekistan, at the Kashkadarya Experimental Station of Uzbekistan’s Cotton Breeding, Seed Production and Agrotechnologies Research Institute in 2018, 2019 and 2020. In research, cotton growth stages such as germination to flowering, flowering to boll formation, and maturation were considered for the development of irrigation scheduling with respect to field capacity water content (Fc). Irrigation scheduling based on percentages of Fc and mineral fertilizer application rate of N250P175K125 should be considered applicable practices for long staple cotton varieties on silt loam soils of the southern zone of Uzbekistan and for similar soil-climatic conditions of Central Asian countries

Experimental studies of pneumatic disc atomizer for low volume spraying

The article presents the results of experimental studies to determine the dependence of the rotational speed of a pneumatic disc sprayer with coaxial air flow on the flow rate of the working fluid. To refine the parameters of the working body, studies were carried out within the liquid flow rate q, corresponding to the first and second spraying modes, at different rotation speeds ω, the working body's radius r, and the number of radial channels np. At the same time, the mass of the rotating part of the pneumatic disk atomizer was determined. The quality of dispersion of the working fluid obtained experimentally by a multi-disk atomizer in a film version driven by an air flow corresponds to a low-volume liquid atomization mode

Experimental studies of frequency of rotation of smooth rotating disk with coaxial-lateral air flow

The article presents methods for determining the main parameters of a rotating atomizer sprayer. The choice of research methodology is justified based on the general pattern of liquid atomization by rotating atomizers, taking into account the influence of the air flow on them. The main indicators affecting the sprayed drops' dispersal are the air flow rate and the rotational speed of the pneumatic disk atomizer. Therefore, the correct choice of the method for determining the rotational speed ω of a pneumatic disk atomizer makes it possible, at a constant air flow rate, to obtain the required median-mass diameter of the atomized droplets. To obtain a high-quality air-droplet flow, there must be a combination between the initial speed of the main drops discharged from the spray disk's periphery and the fan installation's air flow speed