Factors determining the formation of potato yield under conditions of insufficient moisture

The purpose of the research is to identify and recommend for production or practical breeding varieties and hybrid potato material of various genetic and geographical origin, combining high yield, field resistance to mosaic viruses and adaptability to stressful abiotic environmental factors, optimize and improve the efficiency of field evaluation of potato varieties. The research was carried out in 2019-2021 in the Bezenchuk district of the Samara region. 2019 was characterized by a spring drought, and in 2020 and 2021 there was a spring-summer drought. The hydrothermal coefficient was 0.45; 0.47 and 0.61, respectively. In conditions of high temperatures and insufficient moisture, 36 new and promising potato varieties of domestic selection were evaluated according to a complex of economically valuable characteristics. The standards were the varieties Arosa, Gala, Zhigulevsky and Udacha. The experimental material was planted in four repetitions. The number of plants in repetition is 50. The predecessor is spring wheat. The soil of the experimental site is terraced chernozem, ordinary, low-humus, medium-thick, heavy loamy. High yields were characterized by medium-early varieties Krasa Meschery, Debut and Sudarinya, which exceeded the Gala standard by 9.9 t/ha, 4.8 t/ha and 2.8 t/ha; medium-ripened Siversky and Alaska (8.6 and 5.0 t/ha higher than the Zhigulevsky standard, respectively), as well as early-maturing Terra variety (5.0 t/ha above the standard Udacha) The same varieties have high indicators of field virus resistance at the level of 7...9 points to the most harmful X and Y viruses in the conditions of the Middle Volga region. Three main components that have the most significant impact on the variability of the studied parameters are identified. It is shown that field virus resistance was the main limiting factor of yield for the studied set of varieties under conditions of elevated air temperatures and insufficient humidification. The share of the first component accounted for 34.6 % of the variation of signs. It includes, with maximum loads of -0.801, -0.640 and -0.604, respectively, the yield and resistance to potato viruses X, S, and M. The productivity of the studied set of potato varieties was to the greatest extent due to field resistance to viruses X, S, M and, to a lesser extent, to virus Y.

potatoes (Solanum tuberosum L.), drought resistance, virus resistance, productivity, limiting factors