Wp yw g sto ci i terminu siewu na plonowanie kilku odmian pszenicy ozimej w warunkach bezp u nej uprawy roli

The research aimed at analysing the influence of selected crop components on the yield of winter wheat cultivars depending on the term of sowing and seeding density. Experiments were carried out in the years 2004-2006 at the Agricultural Experimental Station, Institute of Soil Science and Plant Cultivation, Jelcz-Laskowice, on a good rye complex soil. In conditions of plough-less tillage the following factors were analyzed: Factor I - terms of winter wheat sowing: 14-16 September; 1-3 October; 15-17 October; Factor II - two seeding densities - 300 grains/m; 450 grains/m. Factor III - winter wheat cultivars: Finezja, Rywalka, Kobiera, Satyna, Bogatka and Zawisza. Early terms of sowing affected higher yields of wheat cultivars than those obtained from optimum terms of sowing and delayed by two weeks. Higher yields of the Satyna cultivar in simplified tillage were due to increased number of ears on a unit of surface as well as to an increased weight and number of grains from an ear. Sowing delayed by two weeks brought about a decreased yield of the Rywalka cultivar, while the Satyna appeared to be more tolerable to late sowing.