Impact of technological practices on the photosynthetic productivity of spring barley in Northern Forest-Steppe conditions

Abstract

Aim. To determine the features of the formation of the photosynthetic apparatus in spring barley plants depending on the influence of individual elements of cultivation technology and to identify the most effective combinations for maximizing the genetic potential of the crop under the conditions of the northern part of the Right-Bank Forest-Steppe of Ukraine. Methods. During the research, a field study method, visual observation, weighing, the «cutting» method, calculations, and statistical analysis were applied. Results. The research conducted during 2018–2020 has shown that the fertilization system, the use of growth stimulants, and the preceding crop significantly influence the photosynthetic activity of spring barley plants at different stages of organogenesis. The leaf surface index values increased and reached their maximum at the VII and IX stages of organogenesis, after which they gradually decreased. The maximum leaf surface area of 5.03 to 5.24 m2/m2 was achieved in crops with the application of N60P80K80+N60(IV) in the presence of the preceding crop’s by-product. The photosynthetic potential of crops during the period from the II to XI stages of organogenesis was at the level of 1.02–2.42 million m2/ha·day when grown after soybeans and 0.92–2.39 million m2/ha·day when grown after corn for grain. The period from the IV to VIІІ stages of plant organogenesis was characterized by the most active accumulation of dry matter and the most significant influence of all studied agronomic practices on the formation of this indicator. Conclusions. Optimal indicators of photosynthetic activity of spring barley crops (leaf area index of 4.65 m²/m² at the VIII stage of organogenesis, net photosynthesis productivity of 6.71 g/m² per day, dry matter accumulation of 9.51 t/ha at the XI stage of organogenesis) are ensured by the cultivation technology that involves the application of mineral fertilizers at a rate of N45P90K90+N45(IV) against the background of the predecessor’s (corn for grain) byproduct and the use of growth stimulants for pre-sowing seed treatment and foliar application at the IV stage of organogenesis. Such parameters of plant photosynthetic apparatus operation contribute to obtaining a barley grain yield at the level of 4.88–5.27 t/ha.