A nanosilicon preparation is superior to a biological preparation and a chemical preparation in activity towards photosynthetic productivity and yield parameters of spring wheat

Wheat is widely used as a food, technical and feed crop. Increased wheat yields can be achieved by mitigating biotic and abiotic stresses using a variety of technologies that include trace elements and growth regulators. Nanosilicon microfertilizer (NanoSilicon LLC, Russia) is an environmentally friendly product containing 50 % of pure colloidal-sized crystalline silicon. This work, for the first time, confirms the positive effect of the Nanosilicon preparation on photosynthetic potential and the net productivity of photosynthesis, the synthesis of chlorophyll, carotenoids and sugars and shows an advantage of Nanosilicon over the pesticide Vincite and an experimental biological product. Under the influence of Nanosilicon, the component structure of the spring wheat yield changed, namely, the number of productive stems, ears and 1000 grain weight increased. Our goal was to examine the effect of Nanosilicon preparation on spring wheat photosynthetic productivity and yield components in the conditions of the Orel region and to compare the effect of Nanosilicon with that of a chemical pesticide and a bioactive preparation. The experiment design included four treatments of spring wheat ( Triticum aestivum L.) cv. Darya seeds (Federal Research Center for Grain-Legumes and Cereals, Streletskoe village, Oryol region, 2016-2019). The seeds were soaked for 2 hours before sowing in water, in chemical pesticide Vinzit (two controls), in a novel biological product based on buckwheat bioflavonoids, and in Nanosilicon concentrate (tests). During vegetation, the control and test treatments were twice applied to the growing plants at tillering and at stem extension phases. The energy of seed germination and germination rate were determined, the development of seed infections was assessed. The phenological phases (three leaves, tillering, stem extension, earing, flowering, milk ripeness, and full ripeness of the grain) were recorded. Photosynthetic potential (PP), photosynthetic productivity and net photosynthetic productivity (NPP) were evaluated, leaf area and the pigment content were measured. It was found that pre-sowing treatment of spring wheat seeds with Nanosilicon contributed to an 18.5 % increase in germination energy and a 5.5 % increase in germination rate as compared to the control treatments. Due to the Nanosilicon application, the plants were taller, resulting in more leaves until the end of the growing season, which indicates a longer leaf life compared to controls. The leaf area was 20.0 % larger at the earing-flowering period compared to the control (water), that was, 14.6 % larger for the biopreparation and 8.3 % larger for the pesticide Vincit. Photosynthetic capacity for control (water), Vincit, Nanosilicon, and the biopreparation was 633360, 686022, 1560384, and 1104894 m2ʺday/ha, respectively. NPP value for Nanosilicon was greater as compared to the controls, by 60-80 % for water and by 22.2 % for Vincit. The amounts of chlorophylls and carotenoids in plants were the greatest at the earing-flowering phase. Under the influence of Nanosilicon and the biological preparation, the synthesis of pigments increased by 20-30 % compared to the controls. Nanosilicon contributed to an increase in the synthesis of sugars in the process of photosynthesis to a lesser extent than the biological product, which can be explained by the difference in the distribution of assimilates and a large accumulation of proteins. The advantages of the Nanosilicon over the bioactive preparation in the number of grains and the 1000-seed weight were minor. Under the effect of Nanosilicon, the number of productive stems increased by 33.7 %, the number of ears by 38.7 %, the ear weight by 26.8 %, the number of grains per ear by 19.2 ear, and the 1000-grain weight by 19.7 % as compared to the control. These indicators for the bioactive preparation were slightly lower than for Nanosilicon, but higher than in control treatments. For four years, the