The influence of different herbicide doses on weed infestation of winter triticale cultivated in monoculture

Abstract

The study was carried out in 2003-2005 in the Bezek Experimental Farm (University of Life Sciences in Lublin). The experimental field was situated on light loamy sand soil. The phosphorus content in soil was high, in potassium medium, in magnesium low. The humus content was 1.2%. The experiment was carried out in randomized blocks in three replications. The aim of the investigation was to compare three doses of herbicides in winter triticale canopy (Janko cv., Woltario cv., Krakowiak cv.) cultivated in monoculture. The herbicides Atlantis 04 WG and Factor 365 EC were applied at full recommended doses (200 g×ha^-1), at doses reduced to 75% and 50%. The control was not treated with the herbicides. The weed infestation level was determined by means of the quantitative-weighting method at two dates: the first one at the 6th week after herbicide application and the second one before harvest. The density of weed individuals was counted; the species composition and air- dry biomass of above-ground parts were estimated from the randomly selected areas of 1 m x 0.25 m at four sites of each plot. The density of weeds and weed air dry weight were statistically analysed by means of variance analysis, and the mean values were estimated with Tukey's confidence intervals (p=0.05). It was found that the number of weeds and air dry mass of weeds in the control were significantly higher in comparison with the herbicide treated objects. The application of different doses of herbicides did not differentiate significantly the weed infestation level in the winter triticale canopy. Viola arvensis, Matricaria maritima, Chenopodium album and Apera spicaventi were dominant species of weeds in the winter triticale canopy. The selection of cultivars did not influence the canopy weed infestation level.