We examined the number of species and individuals of woody vegetation in a total of 150 front gardens in settlements located at three different distances from Kecskemét and affected by suburbanization to different degrees. Most often, one species or two individuals occurred in front gardens, but there were also front gardens with 8 or more species and 14 or more individuals in some cases. The total of 668 recorded individuals belonged to 111 species, among which the first five places were occupied by Biota orientalis, Hibiscus syriacus, Thuja occidentalis, Catalpa bignonioides and Cerasus vulgaris. The combined number of individuals of the five species accounted for 26% of all woody plant individuals observed. The data were evaluated according to several groupings: tree, shrub, hedge or liana; native, archaeophyte or neophyte; fruit tree vs. ornamental tree; deciduous vs. evergreen; and the effect of the electric power transmission lines above the front gardens was also examined. Our results highlight the plant selection habits of the residents, which can be taken into account for the development of appropriate town planning and landscape planning concepts.

The effect of biodiesel-derived by-product (SZO = soap-like emulsion) from rape oil was examined on the germination of common ragweed (Ambrosia artemisiifolia L.) achenes in pot experiments. Soils were treated in three different doses: 2500, 5000 and 10000 liter/ha, applied in proportion to the surface area of the pots. Control soil was moistened with the same amount of tap water. Fifty ragweed achenes were sown into each pot, then the pots were placed in a refrigerator for cold treatment (35 days, +7 °C). Following cold treatment the pots were placed in an unheated greenhouse and the germination of ragweed achenes were monitored for 40 days. Common ragweed seedlings emerged from soils of each treatment including the control, but their rate of germination differed. The highest number of seedlings appeared in the control pots (51.5%), whereas the lowest number was observed in the 2500 l/ha dose pots (33.0%). Order of the treatments according to increasing germination succes was the following: 2500 < 10000 < 5000 < control. Germination rate in treatments 2500 l/ha and 10000 l/ha was significantly lower than it was detected in the control. SZO dose of 5000 l/ha resulted intermediate germination rate of ragweed achenes, that did not differ significantly from any other treatments. Based on the results, the studied biodiesel-derived by-product can potentially be used in weed control. For its appropriate use, the effective chemical components of the SZO should be identified. Further studies needed to determine the optimal dose applicable in field management and to investigate the potential effect of SZO on the germination of cultivated species.