Grain yield and some yield components in various wheat genotypes with different seed sizes

The aim of the research in field conditions was to establish grain yield and some yield components in three wheat varieties depending on seed size, 1.8, 2.0, 2.2, 2.5 and 2.8 mm, using split-plot method in four replications. The highest number of plants (477 and 518) per m 2 was obtained from the 2.5 and 2.8 mm seed size, respectively. The largest number of spikes (561 and 532) per m 2 was obtained from the 2.8 and 2.5 mm seed size, respectively. The highest coefficient of productive tillering of 1.39 was recorded in the 1.8 mm seed size. Remaining seed fractions (2.0, 2.2, 2.5 and 2.8 mm) gave significantly lower productive tillering. There were very significant differences in wheat grain yield over years, varieties, seed sizes and the year × seed size interactions. The highest wheat grain yields of 7.22 t ha -1 and 6.86 t ha -1 were achieved in the case of 2.5 and 2.2 mm seed sizes, respectively. A positive strong correlation was detected between the number of overwintered plants and the grain yield (r = 0.63**). Moreover a positive strong correlation was established between the number of spikes and the grain yield (r = 0.70**), while the negative weak correlation was recorded between the coefficient of productive tillering and the grain yield (r = -0.32**). With the same sowing norm, a large seed produces a significantly higher number of plants and spikes per m 2 than small seed, which is important for the grain yield.