The yield of some wheat varieties sown at the optimum time and in late sowing

Wheat sowing at the optimum time is very important, especially from the aspect of vegetation length, timely wading and rooting of plants, plant development, nutrient utilization rate, and ultimately total wheat yield. It is often the case that due to unfavorable climatic factors, such as drought or heavy rainfall, a delay in the removal of pre-crop and similar occasions. sowing is not carried out at the optimum time. In this case, the plants are underdeveloped, some of them collapse during the winter and in the spring some stages of development are shortened, which altogether results in diminished yields. The paper shows the yield and some components of grain quality of several varieties of wheat sown in the optimal period (October) and in the late-term (early December). The experiments were carried out in 2016/17 and 2017/18, in the area of Southern Serbia (Leskovac) with 5 wheat varieties (Obsesija, Avenue, Sosthene, Farineli and Darija), under the same agro-ecological conditions on alluvium soil. Sowing in 2016/17 was done on October 30, and in 2017/18 on December 8. The results of the experiment show that the average yield of sowed wheat in the optimal period was 6.776 kg ha-1 and those sown in the delayed period 5.091 kg ha-1. The largest yield reductions were observed for the Avenue and Farineli varieties (2,490 and 1,960 kg ha-1). Also, the mass of 1000 grains and hectolitre mass were lower in delayed sowing. These data indicate the importance of an optimum deadline for sowing wheat, which is often not respected in production.