SURVEY ABOUT THE WEED OCCURRENCE ON ARABLE LAND IN THE CZECH REPUBLIC

Current weed spectrum on arable land in the Czech Republic was analyzed and constancy for the individual species determined. Phytocoenological survey was conducted within 2006–2008 on 62 farms. The choice of field selection for sampling was winter cereals, spring cereals, and wide-row spring crops. In the central part of each field phytocoenological relevés sizing 100 m2 were monitored. In total, 172 weed species (58 apophytes, 97 archaeophytes, and 17 neophytes) belonging to 32 families coming from 290 relevés were recorded. Chenopodium album, Fallopia convolvulus, and Viola arvensis were among the species with the highest constancy. Altogether 28 volunteer crops belonging to 8 families were determined (18 dicotyledonous and 10 monocotyledonous). Trifolium repens and Brassica napus subsp. napus were the most frequent volunteers.