THE EFFECTS OF DIFFERENT SOWING DATES ON WINTER WHEAT

Three separate field experiments, with different sowing dates, were conducted to determine a suitable sowing date for the highest agromorphological traits and technological quality parameters. The results in growing season 2022-23 demonstrated the following: with a sowing date delay (i.e., with the second sowing date occurring on November 4, 2022), the grain yield was significantly advanced when compared to the first sowing date (occurring on October 13, 2022), while the grain yield was significantly increased in eight genotypes (out of a total of twelve of them) on the third sowing date (i.e., on November 14, 2022) when compared to the first. The reason for disproportions of grain yield on the first two sowing dates was the attack of barley yellow dwarf virus in autumn that seriously damaged more developed plants pertaining to the first sowing date, whereafter they were also more prone to other wheat diseases. The relative differences concerning the second sowing date with regard to the first one were as follow: an increase by 59.1% concerning the grain yield, by 6.3% concerning the test weight, and by 22.5% concerning a 1000 kernel weight, a decrease by 23.3% concerning the heading date, by 1.2% concerning the protein content, by 2.1% concerning the wet gluten content, and by 2.5% concerning the sedimentation value. The difference in grain yield between the second and the third sowing date amounted to 34.2% due to a premature senescence of plants in later sowing, as a result of increased June temperatures.