Dynamika zachwaszczenia jęczmienia jarego uprawianego w różnych stanowiskach

The experiment with forecrops for spring barley was conducted at the Agricultural Experimental Station of Uhrusk in the years 1997-2002. It was set in the method of split-plots, which was designed in four repetitions. The grey-brown rendzina soil was formed from light loam, weak sandy and it was classified into a very good rye-type soil utility complex. The experiment concerned five forecrops for spring barley: pea, potato, spring barley, spring barley (twice), spring barley (3 times), and two plant care systems: mechanical and chemical. The cultivation of spring barley after barley or potato increased the number of weeds in relation to the remaining forecrops. Herbicides applied in spring barley decrease the number and air dry mass of weeds more effectively than harrowing of a canopy. In each year of the studies and for all forecrops the following occured in the canopy of spring barley: Galium aparine, Stellaria medias and Fallopia. Additionally after potato, pea and spring barley, the studies found out: Melandrium album, Veronica persica, Amaranthus retroflexus, Chenopodium album, Avena fatua and Lamium purpureum