The impact of different densities of selected invasive weeds on the grain yield of three soybean genotypes

The aim of the experiment was to assess the competitive abilities of three soybean genotypes and selected invasive weeds based on soybean grain yield (t ha1). Field trials with competition between three soybean varieties (NS Apolo, Fortuna, NS Zmaj) and three invasive weeds (Abutilon theophrasti, Ambrosia artemisiifolia and Xanthium strumarium) were conducted at Novi Sad (2020-2022). The split split plot design with four replications were used and plot size was 30 m2. Weeds were sown at the same time with densities of 0.5, 1, 5 and 10 weeds per m-1 of soybean row. The three central rows of the plot were used to calculate the soybean grain yield. X. strumarium caused the highest yield losses. Although 2020 was favorable for soybean growth, mean values of grain yield of soybean showed that in some treatments the Fortuna variety was showing higher grain yield compared to NS Apolo and NS Zmaj. Due to the deficit of precipitation in 2021, in the periods when it is necessary for the formation of grain yield and the contribution of other factors, genotypes NS Apolo and NS Zmaj showed higher grain yield than Fortuna. In 2022, which was extremely dry (without enough rainfall during the season), there were no significant differences between genotypes.