Features of adventitious plant naturalization in agrophytocenosis of Donbass

This paper discusses the findings of the adventitious weed plant species inventory and the study of vigor biometric indices of the species characterized by high and average frequency of occurrence in the agrophytocenosis of Donbass with the involvement of cereal crops (winter wheat and spring barley), arable crops (maize, sunflower) and vegetable crops (garden carrot, red beet). The research was carried out in the fields of the OOO Donbass-Agro farm and the Slavyanoserbsk Variety Testing Station (Lugansk People’s Republic) according to generally accepted methods. It was found that 42% of the total number of weeds identified in crops was adventitious plants. Ambrosia artemisiifolia L. and Xanthium orientale L. were distinguished by the highest occurrence coefficient in the crops of cultivated plants; Cyclachaena xanthiifolia (Nutt.) Fresen and Xanthium strumarium L. had medium occurrence. Such species as Turgenia latifolia L., Amaranthus hypochondriacus L., Grindelia squarrosa (Pursh) Dunal were found in crops sporadically. The vigor indices of Ambrosia artemisiifolia individuals were higher in sunflower crops than that in spring barley crops. The biometric indices of age group individuals in Xanthium strumarium populations in different agrophytocenosis differed due to the peculiarities of growth and development of the cultural component. The individuals of different age groups prevailed regarding height in sunflower crops, whereas regarding other vigor indices - in spring barley crops. Cyclachaena xanthiifolia spread on roadsides, in intersegetal ecotopes, and from there it spread to the fields. The most favorable conditions for the growth and development of this species turned out to be in vegetable crops. The tolerant state of the populations of Ambrosia artemisiifolia, Xanthium strumarium, Cyclachaena xanthiifolia in agrophytocenosis and the vigor indices of their individuals despite the crop protection measures in accordance with generally accepted guidelines for the region indicate the successful naturalization of these weed species under the soil, climatic and environmental conditions of Donbass.