Effective management decisions in agriculture, such as timely sowing and harvesting, are crucial for achieving high and stable crop yields. This study analyzed the effects of sowing date on the yield of winter wheat (Tritium aestivum L.). The data used for this analysis were obtained from winter wheat sowing experiments conducted at the Experimental Station in Krasne, University of Rzeszów in Poland, between 2018 and 2021. The first factor examined was the sowing date: I – recommended, II – 30-day delay and III – 60-day delay. The second factor involved two varieties of wheat: RGT Bilanz and RGT Kilimanjaro. The grain yield determined in 2020 decreased by 1.11 t ha-1 compared to the yield obtained in 2019. Wheat sown on the recommended date produced the highest yield (7.99 t ha-1), while yields with 30- and 60-day sowing delays were significantly lower. Compared to the 60‑day delay, the recommended sowing date significantly affected the SPAD and LAI indices, and yield components such as the number of ears per 1 m2 ground area and the number of grains per spike. In addition, sowing wheat on the first date resulted in an increase in protein, starch, phosphorus and potassium content in the grain compared to the third date. It also led to an increase in iron content and a decrease in fiber levels compared to the second and third dates. The variety RGT Bilanz had a significantly higher LAI value, and starch, phosphorus, manganese and iron content in the grain, while the variety RGT Kilimanjaro was characterized by a higher concentration of protein, potassium, zinc and copper in the grain.

28.4.2023