The influence of morphological features of spelt wheat (Triticum aestivum ssp spelta) and common wheat (Triticum aestivum ssp vulgare) varieties on the competitiveness against weeds in organic farming system

One of the methods of weed regulation in organic farming system is a choice of varieties with bigger competitive ability against weeds. The aim of the research was the estimation of the relationships between the morphological features of modern common winter wheat varieties and old variety of spelt (Schwabenkorn) and their competitive ability against weeds, measured by the level of weed infestation. The study was conducted in the Experimental Station of Institute of Soil Science and Plant Cultivation - State Research Institute in Pulawy, Poland (N51 degrees 28', E22 degrees 04'), on the fields used in organic system since 1994. The experiment with different winter wheat varieties was carried out in 2008-2010, in completely randomized blocks. A significant, negative correlation between weed infestation and density of wheat, dry matter of wheat and the height has been proven. There was no significant correlation between tillering and parameters of weed infestation. Different features influenced the level of weed infestation of tested varieties. Smuga and spelt Schwabenkorn were most competitive against weeds, while Kobra and Bogatka were characterized with the smallest competitiveness against weeds. The number and dry matter of weeds were less differentiated because of the variety, and much more because of the years due to different weather conditions.