Dynamics of dry matter content and protein percentage in green mass of Sudan grass depending on the sowing method

Insufficient information on the characteristics of changes in nutrients of Sudan grass according to the phases of growth and development is one of the main obstacles to the widespread use of this crop in feed production. The purpose of the study is to analyze changes in the content of protein and dry matter in green mass of Sudan grass varieties during a vegetation period depending on the sowing method. The research was carried out in the Rostov region on ordinary carbonate chernozem. The growing seasons were characterized by a contrasting hydrothermal regime: in 2022 – average aridity, in 2021 and 2023. – insufficient hydration. The objects of the study were the Sudan grass varieties ‘Aleksandrina’, ‘Alisa’, ‘Gratsiya’, ‘Kudesnitsa’ bred by the Agricultural Research Center “Donskoy”. With the row sowing method (row spacing 15 cm, seeding rate 1.6 million pcs/ha), a more rapid accumulation of dry matter occurs in all studied varieties at the beginning of the vegetation period. By the end of the vegetation period, the dry matter content is higher with wide-row sowing (70 cm row spacing, 340 thousand pieces/ha), by 4.21% on average among the varieties. Rapid accumulation of dry matter was noted from the end of the “heading” phase up to the “milk ripeness” phase. The protein content in dry matter with wide-row sowing at the beginning of the growing season was two times higher than with continuous sowing and amounted to 21.33–24.17 %. Starting from the “heading” phase, the value of the trait decreased sharply and by the time of full grain ripeness it was 5.17–6.74 % for row sowing and 8.01–8.61 % for wide-row sowing. This change in protein in the dry matter of green mass indicates the practicability of using the crop in early stages of the vegetation period to obtain the best feed quality.