The effect of sowing dates, methods and seeding rates on productivity of the grain sorghum variety ‘Zernogradskoe 88’

The current paper has presented the study results of the elements of cultivation technology (sowing date, sowing method, seeding rate) of grain sorghum in the southern part of the Rostov region. Field trials were carried out in 2018–2020. The object of research was the grain sorghum variety ‘Zernogradskoe 88’, included in the State List of Breeding Achievements for the North Caucasus region in 2013. According to the study results there was established that the lowest values of grain weight per plant and 1000-grain weight were formed with a seeding rate of 0.9 million of germinating seeds per ha.In the same variant of the trial, there was determined theworst plants’ preservation before harvesting. Sowing method had the greatest effect on plant density (69.5 %) and on 1000-grain weight (23.8 %); seeding ratehad the greatest effect on grain weight per plant (52.5 %). On average, through the years of study, there was obtained the maximum productivity of 4.14 and 4.12 t/ha with a seeding rate of 0.4 and 0.5 million of germinated seeds per ha, respectively. For grain sorghum, the sowing method with a row spacing of 0.15 and 0.30 m was the most acceptable, where there was yielded 3.70 and 3.65 t/ha. When sowing seeds in the 3rd decade of May (20–22 °C of warming up the soil at a seeding depth), there was identified a maximum productivity of sorghum grain with 3.92 t/ha. The greatest effect on productivity formation (41.6 %) was produced by the seeding rate, the share of the effect of the sowing date was 24.8 %, that of the sowing method was 3.6 %, weather conditions affected on 7.7 %.