STRUCTURE AND POPULATION DYNAMICS OF ASCLEPIAS SYRIACA L. IN THE AGRICULTURAL LAND

This paper evaluates the selected population-biological characteristics and size structure of invasive neophyte Asclepias syriaca in three habitat types (abandoned vineyards, grassland and road side) in the district of Veľký Krtíš in Central Slovakia. Three permanent research plots (1 m × 1 m) were established and monitored during the growing season in 2012. The density of the population at the end of the growing season ranged from 15 to 29 stems per m2. The greatest average plant height was recorded in the roadside plot (129 cm) and the lowest in the abandoned vineyard (92 cm). Main stem thickness reached 1.5-2.0 cm at the base. The highest number of main stem leaves was recorded at the end of June and July (from 24 to 27). The number of inflorescences varied from 1.6 to 3.4 and the number of fruits ranged from 1.2 to 3.8 per generative stem. Statistically significant differences were found in the plant height, thickness of the main stem and the number of fruits at the three different locations.