EN
The influence of soil moisture as results of rainfall sum on weed species composition, primary and secondary weed infestation was studied in vegetable crops (drilled onion, carrot and transplanted leek) in 2009–2010. The results of performed studies revealed that the sum of rainfall did not influence the weed species composition at the primary weed infestation, contrary to the period of second weed infestation. In 2009, due to a low level of precipitation, the number of weed species and their population density were low. In 2010, characterized by a high sum of rainfall, the number of species was comparable at both weed infestation periods; however, the weed population density was much higher at the second weed infestation. In both growing seasons, most dominant weed species were: Chenopodium album, Galinsoga parviflora, Amaranthus retroflexus, Echinochloa crus-galli, and their share in weed abundance ranged from 75.5% (carrots) to 92.0% (onions). The following weed species were permanently present: Gnaphalium uliginosum, Urtica urens, Thlaspi arvense, Matricaria inodora, Lycopsis arvensis, Polygonum persicaria, Aethusa cynapium, Cirsium arvense, Equisetum arvense, Galeopsis tetrahit, and their share in weed community was rather low.