Photosynthetic activity of old-aged crops of Echinacea purpurea in the forest-steppe of the Middle Volga region

Abstract

Plant nutrition is effective if optimal conditions are created for the activity of the photosynthetic apparatus. Forming agrocenoses, with the help of elements of technology and the energy of the sun, their high productivity created by photosynthesis is ensured. Therefore, the purpose of the research is to determine the indicators of photosynthetic activity of Echinacea purpurea of the fourth year of life on various backgrounds of mineral nutrition, depending on foliar top dressing with the Zircon growth regulator. To increase the duration of the use of Echinacea purpurea in 2018-2020, a two-factor field experiment was carried out on old-growth crops on the meadow-chernozem soil of the experimental plot of the Penza State Agrarian University. On average, over three years, in the stemming phase, the most favorable conditions for Echinacea plants developed on a mineral background from two foliar top dressings with Zircon, carried out in the rosette phase of leaves followed by budding, where the leaf area was 25.62 thousand m²/ha and the coverage index was 1.15 times higher than in crops on a natural background. The increase in the photosynthetic apparatus to the budding phase in relation to stalking was 1.47 thousand m²/ha, and during the flowering period, the leaf area increased to 28.31 thousand m²/ha. On average, during the growing season, the photosynthetic potential against the mineral background increased by 1.16 times. Here, during the period of budding - flowering, the highest net productivity of photosynthesis was noted - 1.84 g/m²?day.