In the years 2000 – 2011 (12 years) was conducted weed survey on the farms in conventional farming system. The goal was to detect the most harmful weeds, as important biotic, environmental stress factor, on the farms in the canopies of maize for grain in maize, sugar beet and potato production regions of the Slovak Republic. The fields were selected in all production regions of Slovakia. An actual weed infestation was evaluated before preemergence application of herbicides. Screening of each field was made on 1 m 2 area with four replications. The four randomly established sample quadrants were situated minimally 20 m from field margin and apart from each other, respectively. The level of infestation was evaluated according to average density of weeds per square meter. Obtained data from farms was statistically analyzed by correlation analysis in Statistica 7.0. According to the obtained data and results of weed survey the most troublesome weeds with the heaviest weed infestation level of maize for grain stands were in maize production region Chenopodium spp., Amaranthus spp. and Echinochloa crus galli (L.)P. Beauv.; in sugar beet production region Persicaria spp., Atriplex spp. and Echinochloa crus galli (L.)P. Beauv.; in potato production region Atriplex spp., Chenopodium spp. and Elytrigia repens (L.) P. Beauv. An actual weed infestation depends on production region. After herbicides control the significant changes in weed flora were noted in term of abundance and share of some weed species on total weed community. The dynamics of actual weed infestation depend on climate conditions of maize, sugar beet and potato production region, forecrop and canopy health condition. Weeds are always a problem in maize for grain stands. They can rapidly reduced the yield of maize, but management and control may be considered necessary to safeguard crop quality and yield. The originality of result is in mapping the weed species and its actual weed infestation in cultural crops (maize for grain stands).

maize for grain, weed infestation, mapping

Presentation: oral