Effects of a Variety and a Seed Size on Productive Traits of a Winter Wheat Spike

The effects of the seed size on the spike length, the number of spikelets and grains per spike were investigated in three varieties of winter wheat under field conditions. The four-replicate experiment was set up according to the split-plot method. In order to determine observed properties, a sample of 30 spikes was drawn in the full maturity stage. The analysis of variance showed significant differences in the spike length, number of spikelets and the number of grains per spike over years of investigation in the term of the following interactions: variety × seed size, year × seed size and then varieties × year × seed size. The established variety × year interaction was also highly significant. The longest spike was recorded in 2017 with the 2.8-mm seed. The number of spikelets per spike (21.7) established in 2017 with the 2.8-mm seed size was greater than with remaining seed sizes. The variety PKB-Christina with the highest number of grains per spike (48.1) was followed by the varieties Vizija (46.3) and Pobeda (44.8). Correlations between the spike length and the grain yield (r = 0.169**), the number of spikelets and the grain yield (r = 0.094**) and the number of grain per spike and the grain yield (r = 0.136**) were low and positive. The larger seed had the longer spike which had higher numbers of spikelets and grains per spikes.