Net Productivity Of Photosynthesis Research Articles

THE EFFECT OF MOISTURE LEVELS ON PRODUCTIVITY INDICATORS OF SORGHUM VARIETIES IN THE CONDITIONS OF BUKHARA REGION

The article presents the data obtained based on the study of productivity characteristics of the Karabash, Massino, Samurai, Uzbek Pakana and Uzbek-18 varieties of sorghum under different moisture conditions. It was determined that some of the indicators that determine the productivity in different moisture conditions - the growth rate of the varieties, the expansion of the leaf surface, the net productivity of photosynthesis, etc., change at different levels in the cross-section of the varieties, depending on the level of their resistance.

Influence of preparations on photosynthetic activity of brewing barley (Hordeum vulgare L.) plants and quality indicators of grain

Plant growth regulators and microfertilizers stimulate the accumulation of chlorophyll by plants, increase the photosynthetic activity of chloroplasts and the net productivity of photosynthesis, and contribute to increasing the resistance of crops to diseases and adverse environmental factors. The aim of the work was to study the effect of preparations on the photosynthetic activity the plants of spring barley varieties in order to achieve the proper quality of the grown products. In the research, barley plants of the spring brewing direction of the varieties Sebastian (Seyet Planteforedling I/S, Denmark) and Salomi (SAATEN Union, France) were used, which were treated with plant growth stimulator Vimpel 2, complex microfertilizer ORACUL multicomplex, a mixture of Vimpel 2 + ORACUL multi-complex and control area — water treatment. The article presents the results that show that the content of the sum of chlorophylls a and b in spring barley leaves under the influence of preparations Vimpel 2 and ORACUL multicomplex plays a major role in increasing the productivity of the crop. Accumulation of protein and starch in spring barley grains is one of the most important indicators for growing varieties of brewing value. In all variants of the study, the accumulation of protein in the grain turned out to be within acceptable limits for malting barley (8.75–10.02%), only in the control variant it remained too low. The use of preparations Vimpel 2 and ORACUL multicomplex in a mixture contributes to the accumulation of starch in spring barley grains of both studied varieties. At the same time, treatment with only growth promoter or only micro-fertilizer stimulates the accumulation of starch in the grain compared to the control, but remains at a low level for the brewing industry. The most active growth of the assimilation surface of spring barley plants in all phases of growth was observed after treatment with Vimpel 2 mixture in combination with ORACUL multicomplex. The conducted studies established a significant influence of microfertilizers and growth stimulants on the photosynthetic potential of spring barley crops. During the entire vegetation period of spring barley, the highest photosynthetic potential of crops (FPP) — 859.2 m2/ha×day was determined in the Sebastian variety with the addition of microfertilizer and growth stimulator. The high-quality work of the leaf apparatus of plants is determined by the net productivity of photosynthesis (NPP). The highest PPF index was observed on the Sebastian variety in the variant treated with a mixture of microfertilizer and growth stimulator, which is 27% higher than in the control variant. Therefore, spring barley grain of the required quality can be obtained only under the conditions of optimal combination of the use of preparations of different spectrum of action.

Photosynthetic potential of Malus domestica columnar group

Productivity is one of the primary economic and biological characteristics of an apple tree variety; it is this characteristic that determines the value and economic feasibility of the variety. The photosynthetic activity of the leaf surface of plants plays a leading role in forming the potential productivity of the apple tree. By "potential productivity," we mean the productivity of plants under conditions of ideal agroenvironment, optimal nutrition, and absence of diseases. To diagnose the potential productivity of cultivars we used an indicator of chlorophyll fluorescence induction–induction coefficient (Кі). According to our data, the Кі of leaves of columnar cultivars ranged from 0.720 to 0.740, indicating a high level of efficiency of photophysical processes near the photosystem II (PS II) reaction centers. For plants of columnar cultivars, the viability index ranged from 1.78 to 2.19. It has been established that individual age sections of tree trunks form different productivity potentials. Thus, based on the chlorophyll a (Chl a) fluorescence induction index, a higher intensity of photosynthesis was observed in the leaves of the cultivars ‘Valuta’, ‘Favoryt’, and ‘Bilosnizhka’ on seven to nine-year-old trunks. In contrast, for ‘Tantsivnytsia’, the highest intensity was observed on the oldest spur formation (14–19 years old). In traditional apple cultivars, the intensity of photosynthesis, as indicated by Кі, decreased with the age of spur formation; however, such a decline was not observed in columnar cultivars. The leaves of plants from the traditional cultivar ‘Idared’, situated on a homogeneous shoot, exhibited the highest photosynthetic intensity based on the F680γt / F680βt light intensity. Conversely, in the leaves of three-year-old spur formations, a 25.3% decrease in photosynthetic intensity was observed, falling to a 45.7% decrease in six-year-olds. With the optimal combination of agroecological factors for columnar cultivars, stability in the photosynthetic potential across various complex spur formations is observed. In typical apple cultivars, the age of spur formation leads to a suppression of photosynthetic intensity. The cultivar ‘Bilosnizhka’ is characterized by the highest Chl a/ Chl b content, indicating lower adaptability. In the leaves of this cultivar, the amount of Chl a exceeded Chl b by three times; in contrast, in the cultivars ‘Sparta’ and ‘Tantsivnytsia’, the difference was 2.5 times higher. This value (2.5x) correlates with increased adaptability to the conditions in which they were studied. The highest level of leaf net productivity of photosynthesis (NPP) is observed in plants of the ‘Valuta’ cultivar (13.9 g/m² for day); in the cultivars ‘Bilosnizhka’, ‘Favoryt’, ‘Bolero’, ‘Sparta’, ‘Tantsivnytsia’, and ‘Papirovka’, the accumulation of dry matter is lowered by 32.6–40.6%.

Improvement of cereal harvest programming methods using computer simulation information technology

The paper is dedicated to a topical scientific and applied problem – the development of information technology of computer modelling intended for programming the yield of agricultural crops. The paper describes information technology of computer modelling of the yield of agricultural crops (on the example of Avena sativa subsp. nudisativa), which is based on the application of Bayesian methods to modelling and prediction in conditions of statistical, parametric and structural uncertainty. The study was based on the materials of laboratory experiments carried out in conditions close to natural, on the prediction of physiological processes occurring in plants under the influence of regulated and unregulated factors. Proposed approach described the change in the productivity of grain crops, in particular Avena sativa subsp. nudisativa, depending on the parameters of plant growth and development, photosynthetic apparatus and duration of its functioning. Scientific novelty of the work was application of probabilistic and statistical models in the form of Bayesian networks in the system of programming the yield of agricultural crops. The paper considered several scenarios of the combined effect of growth regulators and herbicides on the productivity of Avena sativa subsp. nudisativa. Net productivity of photosynthesis was chosen as the target variable of the studied process. Mathematical models in the form of Bayesian network turned out to be adequate for the process chosen for modelling. Achieved error of model classification was about 20%. The model structure was built in Genie 2.0 modelling system. It was found that by researching and simulating potential opportunities of ecological features of plants, it was possible to achieve an increase in yield by reducing the doses of herbicides and growth regulators by their combined use, which significantly increased the crop quality. Proposed information technology uses methods of intelligent data analysis, has a modular structure and can be used separately and as part of other information and analytical systems.

Productivity of crop rotations depending on the degree of saturation of alfalfa and winter wheat with stubble natural phytocenosis in the Western Caspian region

The photosynthetic activity of alfalfa and winter wheat with PEF in crop rotations was studied at Vympel-2002 LLC in the Khasavyurt district of the Republic of Dagestan. The soil of the experimental plot is meadow-chestnut, heavy loamy, in the arable layer contains humus 2.77%, K2O - 32.8 and P2O5-2.21 mg / 100 g, its density is 1.24 g / cm3, the lowest moisture capacity of the soil layer - 0.6 m, in which the humidity was studied to determine the timing and norms of irrigation - 29.2%. The studies were carried out in three grain-grass crop rotations saturated with alfalfa and winter wheat with PEF from 25 to 75%, and their monocultures. The formation of PEF for green manure after harvesting winter wheat in the second half of summer, in terms of its influence on the photosynthetic activity of crops of subsequent winter wheat in the crop rotation, made it possible to achieve the same high indicators as after such a most valuable predecessor for it as alfalfa. Despite the fact that the latter, due to its multi-cutting, alfalfa forms 2.8 times more leaf surface area during the growing season, in terms of photosynthetic potential of crops (PPP) and net photosynthesis productivity (NPP) it is inferior to winter wheat with PEF in 1.6 and 6.2 times, respectively. PEF phytomass used for green fertilizer, smoothing out the negative impact of its long-term re-sowing on the phytosanitary state of the soil and the yield of the leading grain crop, can become the most acceptable way out of the situation when, due to the current structure of sown areas, winter wheat occupies 60- 80% of the crop rotation area and it has to be placed in the same field for 3-5 years without a change.

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

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).

The influence of fungicidal protection on the formation of photosynthetic parameters of soybean crops

The purpose of the research was to determine the effect of fungicidal protection on the formation of the leaf surface area and photosynthetic indicators of soybean crops. The research was conducted in 2021– 2023 in the conditions of LLC «Savarske» Obukhiv district Kyiv region. The scheme of the experiment: Factor A. Varieties «Amadea», «Aurelina». Factor B. Fungicides. Control (treatment of seeds and plants with water), «Maxim Advance 195 FS» (1.25 l/t) (treatment of seeds before sowing), «Vibrance RFC» (1 l/t) (seed treatment before sowing), «Selest top 312.5 FS» (1 l/t) (seed treatment before sowing), «Standak Top» (2 l/t) (seed treatment before sowing), «Abacus» (2 l/ha) (during the growing season), «Maxim Advance 195 FS» (1.25 l/t) + «Abacus» (2 l/ha), «Vibrance RFC» (1 l/t) +»Abacus» (2 l/ha), «Selest top 312.5 FS» (1 l/t) + «Abacus» (2 l/ha), «Standak Top» (2 l/t) + «Abacus» (2 l/ha). The maximum indicators of the leaf surface area of soybean plants of the varieties «Aurelina» and «Amadea» were obtained in the phase of grain formation – 44.85 and 45.91 thousand m2 /ha. The smallest assimilation surface of crops was in the budding phase – 15.10 and 15.07 thousand m2 /ha. Under the influence of fungicidal protection the leaf surface area of varieties «Amadea» and «Aurelina» increased by 0.90 and 0.94 thousand m2 /ha in the flowering phase and by 3.11 and 3.46 thousand m2 /ha in the phase of grain formation, compared to control variants. The greatest increase in leaf surface area was noted for the combined use of fungicides «Standak Top» (2 l/t) for pre-sowing seed treatment and «Abacus» (2 l/ha) during the growing season. According to the results of dispersion analysis varietal characteristics (37.7 %) and fungicidal protection (35.4 %) had the greatest influence on the formation of the leaf surface area of soybean plants and the interaction of these factors was 12.3 %. The highest photosynthetic potential of the varieties «Amadea» and «Aurelina» was on the variants of fungicides application «Standak Top» (2 l/t) + «Abacus» (2 l/ha) – 3.09 and 3.16 million m2 × days/ha, «Selest top» (1 l/ t) + «Abacus» (2 l/ha) – 3.08 and 3.14 million m2 × days/ha and «Vibrance» (1 l/t) + «Abacus» (2 l/ha) – 3.06 and 3.13 million m2 × days/ha. The maximum values of the net productivity of photosynthesis in the varieties «Amadea» and «Aurelina» were obtained in the budding phase – 3.88–4.16 and 3.89–4.27 g/m2 × day. The use of fungicidal protection provided an increase of this indicator by 0.07–0.28 and 0.06– 0.38 g/m2 × day, compared to the control options. Depending on the accounting periods, the variety «Aurelina» was superior to the variety «Amadea» in leaf surface area by 1.6–3.8 % in photosynthetic potential by 1.2–2.5 % and in net photosynthetic productivity by 0.8–1.7 %. Key words: soybean, varieties, fungicides, crop protection, leaf surface area, photosynthetic potential, net photosynthetic productivity.

FORMATION OF THE PHOTOSYNTHETIC PRODUCTIVITY OF SOYBEAN CROPS UNDER A BIOLOGIZED FOOD SYSTEM

The process of photosynthesis and the intensity of its work are the basis of the formation of productivity and the level of productivity of agrophytocenoses of agricultural crops, including soybeans. One of the main tasks of modern intensive cultivation technologies is the creation of optimal conditions for the development of the assimilation surface, its long-term operation and the maximum accumulation of organic matter by plants. This scientific article presents the results of field research on the impact of biological preparations of different mechanisms of action created on the basis of phosphorus and potassium mobilizing and mycorrhizal forming bacteria on the photosynthetic productivity of soybean crops at different levels of mineral fertilization, namely on the dynamics of the leaf surface area, the formation of the photosynthetic potential of crops and net productivity of photosynthesis. Field research was conducted on gray forest medium-loamy soils at the experimental field of the Agronomic Research Field of VNAU during 2017-2021. According to the results of the research and the processing of the obtained data, it was established that the use of Groundfix soil biofertilizer at the rate of 5 l/ha during the pre-sowing cultivation period and the pre-sowing treatment of seeds with the biological preparation Micofrend at the rate of 1,5 l/t against the background of complete mineral fertilization ensured the formation of the maximum in the experiment the area of the assimilation surface was 40,4 thousand m2/ha, which exceeded the control by 11,6 thousand m2/ha. In addition, based on the calculations, it was found that this version of fertilizer provided the formation of the highest photosynthetic potential in the experiment at the level of 3,153 million m2 days/ha, and the net productivity of photosynthesis, which, depending on the interphase period, was 5,44, 2,16, 1,76, 2,53 and 1,34 g/m2 per day. The article also provides the results of correlation calculations of the closeness of the connection between the area of the leaf surface, the amount of accumulated dry matter and the level of productivity.

Peculiarities of photosynthesis in spelt (Tríticum spélta L.) in the Forest Steppe Zone of Ukraine

Purpose. To reveal the peculiarities of the influence of the cultivation technology elements on the course of photosynthetic processes in sowings. Methods. The research was carried out in the years 2019–2022 at the experimental field of the Scientific Research Center of Bila Tserkva National Agrarian University (Kyiv region) located in the zone of unstable soil moisture of the Right Bank Forest Steppe of Ukraine. Spelt varieties ‘Zoria Ukrainy’, ‘Europe’, and ‘Atterhauer Dinkel’ were grown with the application of foliar fertilizer potassium humate HK-17 (400 g/ha) in the earing and milk ripeness stages, and Agriflex Amino growth regulator (200 g/ha) in the earing stage. Results. In the flowering stage, the average leaf area in the experiment was 44.9 thousand m2/ha. In particular, in variety ‘Zoria Ukrainy’ it was 45.3 thousand m2/ha, ‘Europe’ 45.5 thousand m2/ha, and ‘Atterhauer Dinkel’ 43.8 thousand m2/ha. A positive effect of foliar application of potassium humate in the earing stage was determined. Potassium humate contributed to an increase in the leaf area in the flowering stage of 2.1 thousand m2/ha, while an increase in the leaf area provided by application of Agriflex Amino in the earing stage was 1.0 thousand m2/ha. In the stage of milky grain ripeness, the average leaf area was 27.1 thousand m2/ha: 27.6 thousand m2/ha in ‘Zoria Ukrainy’, 27.8 thousand m2/ha in ‘Europe’, and 25.9 thousand m2/ha in ‘Atterhauer Dinkel’. The application of potassium humate HK-17 in the earing stage contributed to obtaining a additional leaf area of 0.98 thousand m2/ha and Agriflex Amino of 0.48 thousand m2/ha. At the same time, the application of potassium humate HK-17 in the stage of milk ripeness did not affect the change of this indicator. The highest indicators of net productivity of photosynthesis in variety ‘Zoria Ukrainy’ (1.07–1.08 g/m2 of dry matter per day) were in the treatment with potassium humate HK-17 in the earing stage and repeated in the milk ripeness stage. On the other hand, in ‘Europe' variety, the treatment with potassium humate in the earing stage repeated in the milk ripeness stage in combination with the application of Agriflex Amino growth regulator in the earing stage was 1.17 g/m2 of dry matter per day: it appeared the best treatment. The highest indicators of NPP were in sowings of ‘Atterhauer Dinkel’ variety, despite the fact that it had a slightly smaller leaf area. In particular, in the case of application of potassium humate in the earing stage repeated in the milk ripeness stage, the NPP was 1.18 g/m2 of dry matter per day, and for the combination with the application of Agriflex Amino growth stimulator in the earing stage it was 1.21 g/m2 of dry matter per day. Conclusions. The conducted research confirms the expediency of the foliar application of fertilizer potassium humate HK-17 and growth regulator Agriflex Amino in cultivation of spelt, which improves the course of photosynthetic processes in sowings during vegetation and thus provides optimal conditions for the obtaining high crop productivity.

Peculiarities of the Sorghum bicolor (L.) Moench and S. orysoidum productivity formation under the effect of sowing timing in the western part of the Forest Steppe of Ukraine

Purpose. To investigate the effect of sowing dates of sorghum bicolor and soryz on growth, development and productivity in the conditions of the western part of the Forest Steppe of Ukraine.
 Methods. The following methods were used in the experiments: field, laboratory and mathematical-statistical.
 Results. It was established that, on average over the years of research, the plants of sorghum bicolor and soryz formed higher productivity when the sowing was carried out in the period from beginning to the middle of May, when the soil temperature at a depth of 10 cm exceeded 12°C. At the same time, field germination was 83.2% and 87.1% in sorghum bicolor variety ‘Dniprovskyi 39’, and 80.3% and 82.5 % in soryz variety ‘Samaran 6’. Sowing in late April reduced the field germination by 2.1–8.7 % on average in the experiment The vegetation period for early sowing period was the longest and amounted to 115 days in sorghum bicolor and 116 days in soryz; under optimal sowing conditions, it decreased from 2 to 8 days. The tillering of plants depended on the varietal characteristics and averaged 1.2–1.3 tillers per plant in sorghum bicolor and 1.2–1.4 tillers per plant in soryz. Plant height was 110–116 cm in sorghum bicolor variety ‘Dniprovskyi 39’ and 111–109 cm in soryz variety ‘Samaran 6’. Stem diameter ranged from 1.5 cm to 1.6 cm. The leaf area during the period of “panicle emergence-flowering” reached a maximum for the sowing in the beginning and middle of May and was 30.11 thousand m2/ha and 28.30 thousand m2/ha in sorghum bicolor ‘Dniprovskyi 39’, and 28.43 and 26.96 thousand m2/ha in soryz variety ‘Samaran 6’, respectively. Optimum sowing timing contributed to the formation of high crop productivity, specifically, the grain yield was 3.43 t/ha and 3.67 t/ha, biomass yield 31.83 t/ha and 33.77 t/ha, respectively in ‘Dniprovskyi 39’, and 3.5 and 3.7 t/ha, 29.5 and 37.83 t/ha, respectively, in ‘Samaran 6’.
 Conclusions. It was found that germination energy and laboratory germination of seeds depended on variety, while field germination depended on sowing conditions, such as temperature and soil water content. It was foundd that the early sowing (in the late April) compared to the optimal time (early May and the middle of May) reduced grain yield of ‘Dniprovskyi 39’ variety by 10.1–14.8% and ‘Samaran 6’ by 17.1–21.6%; biomass by 21.9–26.5% and 12.4–31.7%, respectively. Biometric indicators of plant growth and development, as well as the net productivity of photosynthesis, were also higher for sowing seeds at optimal period. Therefore, sowing sorghum in the early and middle May is recommended for the western part of the Forest Steppe of Ukraine.

Efficiency of Complex Biopreparation Use on Winter Wheat Crops in Mordovia

Under field conditions in the Republic of Mordovia, we studied the effect of treatment of seeds and plants of winter wheat varieties Mironovskaya 808 and Skipetr with a complex biological preparation based on jointly cultivated strains PGPB Pseudomonas chlororaphis subsp. aureofaciens and PGPF Saccharomyces cerevisiae on plant growth and productivity. We used seed treatment with the biological preparation diluted with water at a ratio of 1 : 100, and plant treatment during vegetation at a dilution of 1 : 200. The complex biological preparation stimulated an increase in net productivity of photosynthesis and leaf surface, an increase in root dry weight and volume, but not plant height, and an increase in grain productivity by 25–36% compared with control. The stimulating effect of the biopreparation was variety-specific.

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

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.

Features of productivity formation of different maturity terms perennial cereal grasses between mowings depending on the fertilizing system

Purpose. To establish productivity indicators and terms of mowing perennial grasses of different maturity terms depending on fertilizer, Methods. Field, laboratory, mathematical and statistical. Results. The research results of productivity indicators of different maturity terms perennial grasses depending on the fertilization system between the mowings and the peculiarities of the growth of dry biomass during formation of the first mowing on the sod-podzolic soil of the Carpathian region, conducted during 2011-2013, are presented. Conclusions. Productivity of various types of perennial grasses on nitrogen-free backgrounds in the 1st mowing varied between 1.22-1.67 t/ha of dry mass, in the 2nd – 1.06-1.40, and in the 3rd – in in the range of 0.79-1.01 t/ha of dry mass. The most productive in the 1st mowing were Bromus inermis and Phleum pretense L., in the 2nd – Dactylis glomerata, Festuca orientals (Hack.), and Lolium perenne. The most uniform distribution of the dry mass yield in the mowings with the smallest coefficient of variation (6-12%) was characteristic of the Dactylis glomerata, and the least uniform with the largest coefficient (29-35%) – of the Phleum pretense L. Nitrogen had the greatest effect on the productivity of cereal grass stands. With the application of P60K60, productivity increased by 3-23% compared to the variant without fertilizers, and with the application of N90P60K60 – by 1.8-1.9 times. The highest indicators of daily increase in dry mass (75-206 kg/ha), leaf surface area (30.3-43.1 thousand m2/ha) and net productivity of photosynthesis (1.16-4.78 g/m2 per day) in the 1st mowing fell on the period of tuberization-the beginning of the earing of cereal grasses. The growth of productivity of dry biomass, leaf surface area and net productivity of photosynthesis occurs before the flowering phase of grasses.

Photosynthetic activity of sunflower hybrids under growth regulators in the Steppe of Ukraine

The climate of the southern steppe zone of Ukraine in recent years has been characterized by substantial warming, with a low, uneven amount of precipitation during the growing season of plants, which leads to a decrease in the reserves of productive moisture in the soil, and hydrothermal stress occurs in plants. Opportunities to increase the adaptation of plants to adverse factors are the use of plant growth regulators and the use of various methods of tillage aimed at preserving moisture. The purpose of this study was to investigate the influence of the plant growth regulator AKM+Ca on the operation of the photosynthetic apparatus of sunflower hybrids against the background of various methods of basic tillage in the conditions of the Southern Steppe of Ukraine. The following methods were used during the study: field, chemical (to determine qualitative indicators), and statistical (to assess the reliability of data). Field studies were conducted during 2017-2019 on southern heavy loamy chernozems. In the experiment, modified plant growth regulator AKM+Са was used for pre-sowing seed treatment and foliar spraying of sunflower plants (beginning budding phase) of Talento and Colombi hybrids against the background of deep loosening or ploughing. It was found that the use of deep loosening, in contrast to ploughing, helps increase the dry matter content in sunflower plants and the net productivity of photosynthesis due to better preservation of moisture in the soil. The use of plant growth regulator AKM+Са, regardless of the method of soil cultivation, contributes to the increase in the leaf surface area up to 31.2%, increases the photosynthetic potential of plants to 21.6% and the net productivity of photosynthesis to 15.9% during the growing season, and also increases the content of dry matter, compared to the control. The proportion of influence of the plant growth regulator AKM+Ca on the formation of the leaf surface area is 54.2%. The maximum positive effect was obtained with the combined use of AKM+Ca for pre-sowing treatment and spraying of sunflower plants during the growing season against the background of deep loosening of the soil. The research results can be used to adjust elements of agricultural technologies for growing sunflower seeds, increase crop productivity and conduct profitable agribusiness

Photosynthetic productivity of sorghum (Sorghum bicolor L. (Moenh) in the conditions of the Right-Bank Forest-Steppe of Ukraine

Sorghum (Sorghum bicolor L. (Moenh) is a technical, food, and fodder crop and can be used for various purposes, given its value, the acreage should be substantially expanded in Ukraine, and the elements of cultivation technology should be thoroughly examined. The purpose of the study was to determine the effect of the growth regulator on the photosynthetic productivity of sorghum in the conditions of the Right-Bank Forest-Steppe of Ukraine. The following methods were used in the study: field, measuring and weighing, mathematical, and statistical. The study was conducted in conditions of unstable moisture in the Right-Bank Forest-Steppe of Ukraine in 2016-2019. Based on the results of the study, it was determined that the use of a plant growth regulator affected photosynthetic productivity, namely, the leaf surface area, photosynthetic potential and net photosynthesis productivity. The indicators for the content of chlorophylls changed. Thus, the assimilation area of leaves reached a maximum with seed treatment and spraying of crops and amounted to 8.56 thousand m2 /ha during the tillering period, during the period of stem elongation – 29.6 thousand m2 /ha, during flowering and full ripeness – 40.32 and 4.97 thousand m2 /ha. Net photosynthetic productivity in the control was the lowest – 4.67 g/m2 , the use of a growth regulator on seeds and crops contributed to its increase by 0.27 and 0.79 g/m2 . With the treatment of seeds and crops, the net photosynthetic productivity was the highest and amounted to 6.12 g/m2 . The sum of chlorophylls a+b had the highest rates during the tasselling period and, depending on the experiment options, ranged from 4.36 to 5.35. The yield of grain and biomass also varied depending on the use of the preparation, and was the highest in the version with seed treatment and spraying of crops (7.1 and 35.9 t/ha). The close relationship between photosynthetic productivity and the yield of sorghum is also determined. The study can contribute to the widespread use of growth regulators in sorghum crops, ensure the full development of plants, and increase grain yields and biomass

Influence of substrate and nutrient solution on biometric performance and net productivity of garden strawberry seedlings photosynthesis under photoculture conditions

The effect of substrate and nutrient solution on biometric parameters and net photosynthesis productivity of strawberry seedlings of the White Swede variety obtained in vitro under light culture conditions at irradiation power of 126.8 and 172.3 mmol/m2/s was investigated. The highest seedlings with a horn diameter of 0.8 cm were obtained in variants using a mineral wool substrate and nutrient solutions at an irradiation power of 126.8 mmol/m2/s. The irradiation power of 172.3 mmol/m2/s contributed to the largest number of leaves in the variants MV+ PR and MV + 1 MS of 10.0 ± 0.5 pcs. in both cases, and the active development of the assimilation area of the leaves. The irradiation power of 126.8 mmol/m2/s and the use of a nutrient solution contributes to the better development of the root system. The net photosynthesis productivity on an organic substrate using a nutrient solution (CS+1 MS) is 1.5-2.5 times higher than when using an organic substrate filled with fertilizers (GT+water). The net photosynthesis productivity of the leaf apparatus of seedlings grown on a mineral wool substrate at an irradiation power of 126.8 mmol/m2/s was in the range from 0.27 to 0.33 mg/cm2/day, and at an irradiation power of 172.3 mmol/m2/s - in the range from 0.23 to 0.29 mg/ cm2/day.

Photosynthetic activity of old-aged crops of Echinacea purpurea in the forest-steppe of the Middle Volga region

Plant nutrition is effective if optimal conditions are created for the activity of the photosynthetic apparatus. Forming agrocenoses, with the help of elements of technology and the energy of the sun, their high productivity created by photosynthesis is ensured. Therefore, the purpose of the research is to determine the indicators of photosynthetic activity of Echinacea purpurea of the fourth year of life on various backgrounds of mineral nutrition, depending on foliar top dressing with the Zircon growth regulator. To increase the duration of the use of Echinacea purpurea in 2018-2020, a two-factor field experiment was carried out on old-growth crops on the meadow-chernozem soil of the experimental plot of the Penza State Agrarian University. On average, over three years, in the stemming phase, the most favorable conditions for Echinacea plants developed on a mineral background from two foliar top dressings with Zircon, carried out in the rosette phase of leaves followed by budding, where the leaf area was 25.62 thousand m2/ha and the coverage index was 1.15 times higher than in crops on a natural background. The increase in the photosynthetic apparatus to the budding phase in relation to stalking was 1.47 thousand m2/ha, and during the flowering period, the leaf area increased to 28.31 thousand m2/ha. On average, during the growing season, the photosynthetic potential against the mineral background increased by 1.16 times. Here, during the period of budding - flowering, the highest net productivity of photosynthesis was noted - 1.84 g/m2?day.

Корневое питание, фотосинтез и чистая первичная продукция у древостоев рода Picea на уровне организма в пределах российского ареала

A complex retrospective ecological and physiological analysis of the tabular data on the dry weight of stands of the genus Picea growing from the Northwest to the Russian Far East was carried out. Ecological and physiological indicators are calculated per an organism (conditional tree of average weight). Biological productivity (BP, times) was determined by the relative increase in the average dry weight of a tree in adjacent age periods. Quantitative data of mineral productivity (MP, mg/m2/per day) were found by the method of VM. Lebedev, and the net productivity of photosynthesis (NPPh, g/m2/per day) was calculated according to A.A. Nichiporovich at the organism level in stands of each age period in the range from 10–30 to 120–210 years. In all regions, there was a decrease in the element uptake by trees with age: nitrogen (N) by 14.9–93.7, phosphorus (P) by 18.7–119.9 and potassium (K) by 15.4–134.4 times. A sharp decrease in the element uptake continued until the age of 50–60 years, after which it stabilized at an extremely low level. The decline in the root uptake activity resulted in a 2.88–14.0 and 1.64–2.60-fold drop in NPPh and BP, respectively. The correlation between N, P and K uptake with NPPH and BP was highly positive in all zones. Within Russia in 30, 60, 90, and 120-year-old stands differences in the values of net primary production (NPP, g/m2 of nutrition area) reached 5.0, 4.7, 4.6, and 5.2 times, respectively, and net mineral productivity by nitrogen (NMP(N), g/m2 of nutrition area) reached 4.0, 4.3, 4.8, and 4.6 times, respectively. The correlation between these two indicators was described as highly positive. The correlation between the amount of nitrogen uptaken by spruce roots and the efficiency of its use in forming a unit of biomass was highly negative in all regions. The center of the Russian Plain and the Middle Volga region were the best regions for the growth of spruce plants, while the Krasnoyarsk and Khabarovsk (north) Krais were the worst.

Формирование урожайности сортами чины посевной при разных способах посева и регуляторах роста на каштановых почвах предгорного Дагестана

The above scientific work presents the results of research on the study of the adaptive potential of cultivars of the seed rank (Crustacean and Marble) on dark chestnut soils of Foothill Dagestan. As follows from the conducted field experiment, the growth regulators Rhizotorphin and Albit used contributed to the reduction of harvest ripeness of the above varieties. It was found that the maximum indicators of photosynthetic activity of the studied varieties were provided with an ordinary method of sowing with a row spacing width of 0.30 m and pre-sowing treatment with growth regulators. Compared with the control variant (without treatment with growth regulators), on average, the leaf surface area and net photosynthesis productivity increased by 3.7-6.9 and 6.3 -12.4%, respectively, against the background of the use of growth regulators Rhizotorphin and Albit. Compared with the ordinary method of sowing with row spacing of 0.15 m and with a wide-row with a width of 0.45 m, the excess in the variant with ordinary sowing with a width of 0.30 m was 9.9- 8.3, respectively; 5.2- 5.4 and 14.7-15.0; 11.3-7.3%.Analysis of the formation of the leaf surface area and the net productivity of photosynthesis by varieties of rank he showed that the most acceptable data was provided by the Marble variety. It was revealed that the studied varieties provided the maximum seed yield when treated with the growth regulator Albit, compared with the control variant and the variant with the regulator Risitorfin, the increase was 16.8 and 8.6%, respectively. The most preferred of the sowing methods turned out to be an ordinary method with a row spacing of 0.30 m, where the yield on average for varieties and regulators was higher than the first and third options by 14.8 and 10.4%, respectively. The highest yield was provided by the Marbled variety, the increase compared to the Crustacean variety on average by sowing methods and variants with growth regulators was 5.5%.

Урожайность сортов нута в условиях предгорного Дагестана в зависимости от применяемых агроприемов

According to many researchers, chickpea as a drought-resistant crop in arid regions of the country is promising. In the Republic of Dagestan, research aimed at developing elements of the technology of this crop has not been carried out, and therefore, improving the methods of cultivating chickpeas in the Piedmont province of the republic is an urgent task, which has both theoretical and great industrial significance. Experimental data showed that chickpea varieties had the highest indicators of leaf surface area and net productivity of photosynthesis when treated with the Rizotorfin regulator in the case of using an ordinary sowing method with a width of 0.30 m. Vega variety provided sufficiently high data on photosynthetic activity. Thus, the leaf surface area and NPP in this case amounted to 26.7 thousand m2/ha and 3.90 g/m2 day, respectively. On crops with varieties Volgogradsky 10 and Privo 1, these data were lower by 9.9 - 6.0 and 10.5 and 5.1%, respectively. On average, for options with sowing methods and varieties, the maximum yield, at the level of 1.55 t/ha, was noted on plots with the Rizotorfin regulator, which is 11.0% more than the data of the control variant. The analysis of this indicator, depending on the sowing methods, showed that the row sowing method with a width of 0.30 m turned out to be the most appropriate, where the yield was 1.73 t/ha, which is more than the data of row sowing with a width of 0.15 m and wide-row sowing with a width 0.45 m, respectively, by 24.5 and 14.6%. The highest yield was recorded in the variety Vega, in comparison with the varieties Volgogradsky 10 and Privo1, it increased by 30.6 and 15.1%.