CHANGE IN INDICATORS OF PHOTOSYNTHETIC ACTIVITY OF ECHINACEA PURPUREA SEEDINGS IN THE SECOND YEAR OF LIFE

Abstract

The effective implementation of the plants biological potential occurs with a high culture of agriculture, as well as optimal moisture conditions and air temperature. Echinacea Purpurea has long-lasting seed germination and low competition to weeds; therefore, when cultivating it, it is relevant to determine the optimal sowing time and an effective way to combat the weed component. In this case, the study of the photosynthetic apparatus parameters is greatly important. According to the results of studies carried out in 2016 - 2018 on the chernozem-meadow soil of the experimental plot of Federal State Budgetary Educational Institution of Higher Education, Penza State Agricultural Academy, it was found that, regardless of weather conditions, the largest area of the assimilation surface is formed by sub winter crops with pre-emergent application of herbicide Lazurit and subsequent treatment with Miura in the phase of 2-4 weed leaves, and also with manual removal of segetal vegetation. On average, over three years, it reached its maximum in the flowering period and made up 50.3 and 49.9 thousand m2/ha. The photosynthetic potential on sub winter sowing in the shooting stage exceeded this indicator on early spring crops with double chemical weeding by 1.4 times, and during budding and flowering - by 1.2 times, with manual removal of weeds by 1.2, 1.1 and 1.2 times, respectively. The highest average daily net photosynthesis productivity of 2.73 g/m2 ? day was observed on early spring crops in the flowering phase, especially after a single chemical weeding with Miura’s herbicide.