The results of the weed survey on arable land conducted in 1997-2005 in the Slovak Republic were applied to asses the distribution and occurrence of weed species with respect to their importance and harmfulness in maize fields situated in marginal production region. Four infestation levels from weak to heavy were used. One or two maize field on each 16 pilot farms situated in selected region according crop rotation and tillage and weed management has been evaluated. The most troublesome weeds were established late emerging spring weeds Atriplex spp. and Chenopodium spp. in sugar beet production region. Amaranthus retroflexus L., Atriplex spp., Chenopodium spp. dominated also in maize field in potato production region. The results are discussed in relation to harmfulness between production regions.

weed density; weed diversity; maize

Presentation: oral