Results of the study of the weed-field flora of Primorsky Territory in 2016-2020

Abstract

The results of the study of the weed component of soybean, early grain crops and maize agrocenoses in Primorsky Territory are presented. In total, 111 species of weeds belonging to 35 families were found during the period from 2016 to 2020. Compared with the results of crop surveys conducted in 2006-2015, the total number of species detected has increased by 23. The largest number of species belongs to the families Asteraceae (24), Poaceae (15), Polygonaceae (11), Fabaceae (9), Brassicaceae (8), Caryophyllaceae (7) and Lamiaceae (5). The remaining 26 families were represented by 1-3 species each. For the first time weeds-representatives of the families Scrophulariaceae, Violaceae, Lythraceae, Onagraceae, Asclepiadaceae and Boraginaceae have been discovered. The floristic composition of soybean agrocenoses was the highest with 108 weed species from 31 families. In cereal and maize crops, weed diversity was less significant, with 75 species in 22 families and 72 species in 25 families, respectively. Weed vegetation in all the above crops is represented by 62 species of 19 families. The main weed species that grew on 97-99% of the surveyed territory with a sufficiently high average density of standing (21-61pcs/m2) were Asian copperleaf, cockspur grass and common ragweed. Also, more than half of the surveyed crops of soybeans, cereals and corn were hairy cupgrass, perennial sow thistle, common couch-grass, common lamb’s quarters, wormwood species, field horsetail, yellow thistle, dayflower and yellow foxtail. Practical measures to protect against weeds on the Primorsky Territory should be primarily aimed at controlling these species.