Competitiveness of spring-sown wheat varieties in littered agrofitocenosis in the northern forest-steppe of the Tyumen region

Specific composition and quantity of weed plants in the agrofitocenosis of spring-sown wheat, and also competitiveness of varieties concerning a weed component in the conditions of Northern Zauralie is given. As material of a research served 8 mid-season spring-sown wheat varieties allowed to use. Field experiments were made in 2012-2014 on the pilot field GAU of Northern Zauralie. Accounting and observations in experience was made according to methodical recommendations of N. Z. Milashchenko. In the agrofitocenosis of spring-sown wheat in years of a research 18 species of weed plants met. The greatest number of species belonged to summer one-year weeds. In all years of a research in the agrofitocenosis Atriplex patula, Erodium cicutarium, Setaria glauca, Sonchus arvensis met. Depending on a year of a research the greatest number of weed plants is noted in the agrofitocenosis of varieties Ikar (140 pieces/sq.m - 2012), Skent 1 (46 pieces/sq.m - 2013) and the Lutescens 70 (69 pieces/sq.m - 2014), and the smallest - at Aviada (57 pieces/sq.m - 2012), Chernyava 13 (29 pieces/sq.m - 2013) and Skent 3 (32 pieces/sq.m - 2014). The share of a weed component was characterized by strong variability depending on year of a research and a variety. Its smallest value in the conditions of 2012 is noted at a variety Chernyava 13 (10,2%), 2013 - Skent 3 (7,7%) and 2014 - Aviada (0,5%). Irrespective of a year of a research productivity of varieties decreased in the conditions of a contamination in comparison with net from weed plants of the agrofitocenosis. In the conditions of a contamination varieties Tyumenskaya 80 and Aviada were characterized by the smallest decrease in productivity. Proceeding from the quantity of weed plants, a share of a weed component, on competitiveness on average for 2012-2014 the variety Aviada was characterized by the smallest decrease in productivity, both in net, and in the littered agrofitocenosis is recognized as the best.