PROTEIN CONTENT IN WINTER WHEAT GRAIN IN THE NORTHERN STEPPE OF UKRAINE
Authors:   Central Ukrainian National Technical University, Mostipan Mykola 
Published: November 2024

The subject of the study was the conditions of formation of high-protein winter wheat grain. The main goal of the research was to identify the relationships between the main agrotechnical practices, weather conditions in the early spring and protein content in winter wheat grain and to create methodological foundations for the development, implementation and adjustment of ecologically adaptive technologies for growing winter wheat in the northern Steppe of Ukraine. The research was conducted during 1986-2005 at Kirovohrad State Agricultural Experimental Station. The winter wheat was sown in three terms on 25 August, 17 September and 2 October after black fallow and non-fallow maize silage predecessor. The protein content of the grain was determined by conventional methods. The soils of the experimental plot are ordinary medium-humus heavy loamy deep chernozems. It has been substantiated that in the northern Steppe of Ukraine, winter wheat under black fallow provides a higher protein content in grain compared to its non-fallow predecessor. During the years of research, the protein content in the grain of winter wheat under black fallow was 13.94 compared to 13.0% after corn for silage. After both predecessors, both high and low amounts of protein can be accumulated in winter wheat grain at high yields. Shifting the sowing dates of winter wheat from 25 August to 2 October for black fallow, on average over the years of research, causes a decrease in the protein content of grain from 14.2 to 13.7%, and for corn for silage, on the contrary, an increase from 12.9 to 13.1%. However, this dependence can be clearly seen in 74% of years under black fallow and 47% of years after the non-fallow predecessor. In the conditions of the northern Steppe of Ukraine, the time of renewal of the spring vegetation of winter wheat plants affects the protein content of its grain. The average (third decade of March) time of spring vegetation recovery of winter wheat plants contributes to a higher protein content in the grain, which is 14.2% after black fallow and 13.37% after corn for silage. In years with an extra-early (third decade of February) renewal of spring vegetation, the lowest amount of protein is accumulated in winter wheat grain after both predecessors. The nature of the air temperature regime in the early spring period determines the protein content of winter wheat grain. When winter wheat is placed on black fallow, the highest protein content in winter wheat grain is observed in years when the average daily air temperature passes through 00C in the third decade of February and is 14.45%, and after the non-fallow predecessor – in the first decade of March – 14.16%. The highest amount of protein in winter wheat grain after both predecessors is accumulated in the years with a period from the time of transition of the average daily air temperature through 00C to active vegetation of plants from 20 to 30 days and after black fallow is 14.57%, and after non-fallow predecessor – 13.35%. In the years with the duration of this period exceeding 30 days, grain with the lowest amount of protein is formed. A sharp decrease in the protein content of winter wheat grain in the northern Steppe of Ukraine is observed in the years with an average daily air temperature during the period of ‘spring vegetation renewal – heading out’ above 110C. After black fallow, the protein content of grain decreases from 15.0 to 13.0%, and after corn for silage – from 14.3 to 13.3%. An increase in the duration of the period ‘restoration of spring vegetation – heading out’ increases the protein content in winter wheat grain. In the years with the duration of this period exceeding 35 days, the amount of protein in winter wheat grain for black fallow increases by 1.7%, and in corn for silage by 0.8% compared to the years with duration of this period not exceeding 25 days.