Effect of sowing date on yield of winter wheat cultivars Grom, Asr and Kuma in Khorezm region

In order to determine the influence of different sowing dates on grain yield of cultivars winter wheat field experiment was set up in Khorezm region. The aim of this study was to evaluate the optimal date of sowing winter wheat according to the results obtained in practical production. For the experiment, we used three sowing dates: D-1 = 1st of October, D-2 = 10th of October, D-3 = 20th of October which were conducted in the field No 119 of the Dildora-Bojimon farm of Yangibazar district of the Khorezm region. An experiment was done using winter wheat (Triticum aestivum L.) cultivars Grom, Asr and Kuma. The research material comprises results of farm surveys conducted in years 2014-2016. Results of three-year studies at a location in Yangibazar reviled that different sowing dates significantly affected on grain yield of cultivars winter wheat. They were in the range of 6750 kg/ha(-1) to 6840 kg/ha(-1) of winter wheat cultivars: Grom, Kuma and Asr during three years of experiment. The relatively highest grain yields in three years of investigations were achieved with the sowing on optimal time. Kuma produced the highest grain yield among all varieties, while, minimum grain yield was produced by Grom.