Photosynthetic activity - as a factor in the formation of yield and quality of the new grain fodder oat variety Irtysh 33

Abstract

The purpose of the research is to assess the influence of photosynthetic activity of the new promising oat variety Irtysh 33 on the formation of its yield and quality of green mass. The experiments were performed in 2017-2022. The soil of the experimental plots is ordinary leached chernozem with a humus content of 5.7…7.5 %. The experiment was carried out in 4 repetitions. The seeding rate is 4 million viable seeds/ha. The area of the plots is 10 m2. The object of research is a new promising oat variety Irtysh 33, the standard variety is Orion. Optimal moisture supply was observed in 2019 (hydrothermal coefficient = 1.10), excess moisture in 2018 (hydrothermal coefficient = 1.39), and dry conditions in 2017, 2020-2022. (hydrothermal coefficient = 0.58-0.77). On average, over the period of research, the variety Irtysh 33 was characterized by a more developed leaf apparatus (35.5 and 24.9 % higher than the standard for leaf surface area in the sweeping and flowering phases, respectively). The new variety was characterized by an increased mass fraction of dry biomass, exceeding the Orion standard by 14.6 % in the heading phase and by 10.2 % in the flowering phase. The Irtysh 33 variety provided photosynthetic potential 30 % higher than the standard. The new variety generated forage yields that were 7.3 and 3.2 t/ha higher than the standard in the heading and flowering phases, respectively. An increased quality of forage mass of the Irtysh 33 variety in the heading phase was also noted - higher than the standard for the mass fraction of protein by 0.4 %, for protein collection by 1.07 t/ha and 0.7 % lower than the standard for the mass fraction of fiber. Indicators of photosynthetic activity had a direct impact on the formation of the yield and quality of green mass of the Irtysh 33 variety, depending on the development phase. From spawning to flowering, the role of accumulation of dry biomass on the formation of the mass fraction of fiber (from r=0.515±0.02 to r=0.684±0.103, respectively) and yield (from r=0.479±0.008 to r=0.602±0.015) increased, as well as the role of net productivity of photosynthesis (for the accumulation of dry biomass from r=0.115±0.004 to r=0.419±0.017; for yield from r=0.460±0.020 to r=0.601±0.051). The average direct degree of conjugation of the assimilation surface of the leaf with the mass fraction of protein, noted in the sweeping phase (r=0.640±0.19), in the next phase changed to the average reverse (r= -0.508±0.021).