Temporal dynamics of actual weed infestation in the sugar beet canopies

Abstract

The aim of this study was to detect the most harmful weeds in the canopies of sugar beet during the years 1999-2009 in the Slovak Republic. The actual weed infestation was evaluated by a counting method per square. The four randomly established sample quadrants were situated minimally 20 m from field margin and apart each other, respectively. Temporal dynamics of all weed species in the canopies of sugar beet were statistically analyzed. In the sugar beet fields the most problematic weeds were: perennial weed (Cirsium arvense(L.) SCOP, Elytrigia repots (L.) DESV, Convolvulus arvensis (L.)), annual weeds (Chenopodium spp. Amaranthus spp., Atriplex spp., Persi-caria spp., Echinochloa crus galli (L.) BEAUV., Datura stramonium (L.), Mercurialis annua (L.), Panicum capillare (L.), lea xanthiifolia Nun.) and cultural crops winter oilseed rape (Brassica napus (L.)). Temporal dynamics of actual weed infestation depend on climate conditions of production region, forecrop and canopy health condition. The most dangerous weed species were Persicaria spp., Amaranthus spp., Atriplex spp., Chenopodium spp. and Echinochloa crus galli (L.)P.BEAUV, which infested more than 90 % of sugar beet fields in maize and sugar beet production region.