Photosynthetic Activity as a Factor of the Yield Formation and Quality of the New Grain Irtysh 33 Fodder Oat Variety

Abstract

The purpose of this research was to assess the influence of photosynthetic activity of a new promising oat variety, Irtysh 33, on the yield formation and quality of green mass. Experiments were carried out in 2017–2022 in Western Siberia. The soil is leached common chernozem. The moisture level was optimal in 2019 (HTI = 1.10), excessive in 2018 (HTI = 1.39), and low in 2017 and 2020–2022 (HTI = 0.58–0.77). The object of the research is the new promising variety Irtysh 33 (the standard is the Orion variety). On average, Irtysh 33 was characterized by a more developed leaf apparatus over the study period, with an assimilation surface area being 35.5% higher in the heading phase and 24.9% higher in the flowering phase than that of the standard. The mass fraction of dry biomass of the new variety was greater than that of the standard variety in these periods (by 14.6 and 10.2%, respectively); the yield of the fodder mass was 7.3 and 3.2 t/ha higher, respectively. Such results are determined, among other things, by an increase in the photosynthetic potential of the Irtysh 33 variety by 30% compared to the standard variety. In the heading phase, the protein content in the fodder mass was 0.4% higher, the protein yield was 1.07 t/ha higher, and the mass fraction of fiber was 0.7% lower in the new variety than in the standard variety. The influence of the accumulation of dry biomass on the formation of the mass fraction of fiber increased from heading to flowering from r = 0.515 ± 0.02 to r = 0.684 ± 0.103, its effect on the yield increased from r = 0.479 ± 0.008 to r = 0.602 ± 0.015; the effect of net photosynthetic productivity on the accumulation of dry biomass increased from r = 0.115 ± 0.004 to r = 0.419 ± 0.017, and its effect on the yield increased from r = 0.460 ± 0.020 to r = 0.601 ± 0.051. The medium direct correlation of the assimilation leaf surface with the mass fraction of protein, recorded in the heading phase (r = 0.640 ± 0.19), changed for the medium inverse correlation in the next phase (r = –0.508 ± 0.021).