Abstract
Sugar sorghum and sorghum-sudangrass hybrids are rare crops in Northern Kazakhstan. One of the constraints to the introduction is the low range of varieties and hybrids adapted to the climate of a region characterized by heat, moisture and a short frost-free period. Now an important factor is the selection of short-season variety and hybrids able to achieve: milky-wax ripeness (for feed); wax and complete ripeness (for seeds). Nine varieties of sorghum sugar and seven sorghum-sudangrass hybrids were used as research target. Experiments were carried out in 2020-2022 on the practice field of Kokshetau University named after Sh. Ualikhanov. Research has revealed varieties capable of ripening to complete ripeness of seeds: Capital (growing period on average 101 days) and Volunteer (103 days). Also, varieties ripening to wax ripeness are defined: Seville, Sahara, Volzhskoe 51 and Chaika. Under regional conditions, the optimum period from seeding to flowering should be considered 70-75 days. Studied sorghum-sudangrass hybrids did not have time to form seeds and are recommended for hay, and green feed. The results of the research show the possibility to select sugar sorghum under the conditions of Northern Kazakhstan, and open the prospects for local varieties.