Laboratory and field experiments were carried out at the experimental site of the Research Institute of Breeding, Seed Production and Agricultural Technology of Cotton Growing, located in the Kibray District of the Tashkent Region at 42 degrees north latitude, at an altitude of 481 m above sea level. The soil is a typical, cultivated gray soil of old irrigation from the Boz-Su main channel. Agrotechnical measures were carried out in accordance with the recommendations of the Uzbek Cotton Research Institute for the conditions of typical gray soils with deep groundwater. For each fruit branch the weight of one capsule, the number and weight of 1000 seed pieces were determined under laboratory conditions, their germination. It is shown that the high quality of cotton seeds guarantees control over their varietal and sowing characteristics. The yield, and therefore the number and size of the bolls are influenced by many factors – climate, soil, growing zones, annual rates of NPK mineral fertilizers, irrigation regime, agrotechnical methods, and others. Most of all yield volume depends on the rate of application of mineral fertilizers. On sown areas the field germination of cotton seeds, as a rule, is no more than 75-80%. Bringing it to 90% and above will provide the most complete plant stand density, while the seeding rate will decrease and the weight of 1000 seed pieces will increase. It was revealed that this indicator in comparison with the number of seeds in one seed capsule by the tightness of the connection, is characterized by a curvilinear dependence with a correlation ratio η = 0.885. The closeness of the connection between the field seeds germination and the opening of the capsules was established: with it’s increasing the percentage of opening decreases.

The article considers the issues of determining the rational plots of irrigated plots on lands inhabited and subjected to irrigation erosion. Rational areas of irrigated plots are determined based on the optimal aspect ratio of the irrigated plots, the degree of salinity of soils, the slope of the irrigated surface, and the flow rate of water in irrigated furrows. The optimal combination of irrigators and drains, which are the boundaries of irrigated plots and optimal distances between drains, were also taken into account. Recommended rational areas are defined for slightly, medium, and highly saline, as well as lands subject to irrigation erosion.

The purpose of the research was to study the hydraulic conditions of the flow supply in the new design of the curved suction pipe and to study the effect of these conditions on the pump operation. Improving the suction pipes provides a predetermined schedule of water supply, reducing unproductive losses and the cost of electricity for water lifting. Therefore, such studies are relevant. The article uses methods of physical modeling with the introduction of the obtained data on full-scale structures. The values of the dimensionless coefficients and the corresponding hydraulic gradients for various times are studied on a suction pipe model at Qmax and Qmin, over the entire range of operating parameters. The chosen method of improving the suction pipes provides an optimal water supply schedule, reducing unproductive losses and electricity costs for water lifting. During the reconstruction of pumping stations, projects for the modernization of water supply facilities were introduced with annual energy efficiency amounting to 1312 million sum for the pumping stations Kuyumazor, Kiziltepa-1 - 105 million sum.