Influence of hydrothermal conditions on aniseed lophanthus seed productivity

The aim of the study is to identify the influence of agrometeorological conditions on the structure and biological yield of aniseed lofanthus (Lophantus anisatus Benth.) seeds in the dry steppe part of the Republic of Khakassia. The studies were conducted in the introduction nursery of the botanical garden of the Research Institute of Agronomy of Khakassia - a branch of the Federal Research Center of Agricultural Sciences of the Siberian Branch of the Russian Academy of Sciences in 2021-2023. The object of the study was first-year aniseed lofanthus plants grown by seedlings. Observations and records complied with the accepted methods. According to the results of the correlation analysis, it was established that temperature conditions have a strong influence on the elements of seed productivity of lophanthus (r = 0.78-0.99), while precipitation has a weak to moderate effect. Seed productivity was strongly correlated with the structural elements of the yield: the number of cymoids and flowers in a cymoid, the length of the thyrsus (r = 0.84; 0.99; 0.94); potential (PSP) and real (RSP) seed productivity (r = 0.99); weight of 1000 seeds (r = 0.95). The sum of active air temperatures during the entire vegetation period had a positive effect on the seed yield (r = 0.72). Excessive moisture in the initial period of growth and development of the aniseed lophanthus had a weak negative effect on seed productivity (r = -0.23). A strong correlation dependence of seed productivity on the amount of precipitation during the flowering period of the aniseed lophanthus (r = 0.99) was revealed; the combined effect of hydrothermal conditions during this period was also manifested to a greater extent compared to other periods of growth and development. To obtain a potential seed yield, it is necessary to maintain an optimal moisture regime from the beginning of flowering until the ripening of the aniseed lophanthus seeds.