TEMPORAL DYNAMICS OF ACTUAL WEED INFESTATION IN WINTER RAPE CANOPIES PUBLISHEDŠtefan Týr, Tomáš Vereš
In the years 1994 – 2009 (15 years) was conducted weed survey on the farms in conventional farming system. The aim was to detect the most harmful weeds, as important biotic, environmental stress factor, on the farms in the canopies of winter rape in sugar beet production region of the Slovak Republic. The actual weed infestation was evaluated by standard methods common used 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. In the winter rape 16 weed species were detected, the most problematic were: perennial weed (Cirsium arvense, Elytrigia repens), annual weeds (Chenopodium spp., Stellaria media, Viola spp., Avena fatua, Anthemis spp., Lamium spp., Papaver spp., Galium aparine, Apera spica-venti, Tripleurospermum perforatum, Matricaria spp., Descurainia sophia) and cultural crops winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.). Temporal dynamics of actual weed infestation depend on climate conditions of production region, forecrop and canopy health condition. The efficacy of herbicides was assessed according changes of weed population before and after herbicides application. Present study assessed the actual weed infestation of dominant weed species in canopy of winter rape in 1994 – 2009. After herbicides control the significant changes in weed flora were noted in term of abundance and share of some weed species in weed community. Contamination of agrophytocenosis and herbicide costs lead us to idea to grow agricultural crops by using only cultural, preventive and mechanical weed regulation methods. The originality of result is in mapping weeds species in Central Europe (Slovak Republic).
temporal dynamics; actual weed infestation; mapping; winter rape