Sum Of Active Temperatures Research Articles

Фенологические особенности развития сортов вишни в меняющихся погодно-климатических условиях

Annotation. Cherry is a stone fruit crop cultivated in almost all regions of Russia. Currently, there is a significant change in weather and climatic conditions, their impact leads to a shift in the phenological phases of plant development and to disruption of the stages of organogenesis. In this regard, there is a need to study the passage of phenological phases of cherry development in the changing weather and climatic conditions of the southern region. The research was carried out on the basis of the collective use center (CUC) “Genetic collection of fruit crops” in the period 2020-2023 in the Kuban horticulture zone of Krasnodar region. The objects of research were 11 varieties of sour cherries of various ecological and geographical origins. Planting scheme is 5x3 m, rootstock is antipka seedlings. During the research, the sum of active temperatures during the cherry growing season was determined, which determines the occurrence of the main phenological phases of development of cherry varieties in the annual development cycle. It was established that over the years of research, on average, the sum of active temperatures exceeded the long-term average by 551,7 °C. It was determined that during the research period the phenological phase “beginning of growing season” of cherries took place at a sum of temperatures of 32.8-54.2 °C. The phenological phase of “beginning of flowering” for most varieties in 2020 and 2023 occurred earlier than the long-term average date by 2-8 days, in 2023 – by 2-6 days, and in 2021-2022 – later by 2-14 days. It was revealed that at the phenophase "beginning of flowering", early cherry varieties (Krasnodarskaya sladkaya, Chudo vishnya), medium (Timati, Feya, Assol’, Svatlaya) are strongly affected by stress. Tamaris and Hodosa cherry varieties of late ripening showed relatively high resistance to stress during the flowering period. Key words: cherry, variety, phenological characteristics, flowering, climate.

Assessing the Impacts of Mulching-Induced Warming Effects on Machine-Picked Cotton Zones

The 20th century saw notable fluctuations in global temperatures, which significantly impacted agricultural climate zones across the Earth. Focusing on Xinjiang, China, a leading region in machine-picked cotton production, we identified several key thermal indicators influencing the yield, including the sum of active temperatures ≥ 10 °C, the mean temperature in July, the climatological growing season length, the April–May sum of active temperatures, the last frost day, and the defoliant spray time. Using meteorological data from 58 weather stations in Xinjiang, we examined the spatiotemporal trends of these indicators during the 1981–2020 period. Additionally, we attempted to determine the effects of plastic mulching on the sowing area and the zoning area of machine-picked cotton in different suitable zones based on these indicators. In conclusion, the overall thermal resources in Xinjiang are exhibiting an upward trend and show a distribution pattern of “more in the south of Xinjiang than in the north of Xinjiang, and more in the plains and basins than in the mountains”. Under the plastic-mulching mechanism, the zoning area of the suitable zone has increased by 15.7% (2.15 × 103 km2), suggesting that climate warming and the widespread application of mulching technology provide unexplored potential for the most suitable regions for machine-picked cotton in Xinjiang, while the 14.5% (0.26 × 103 km2) and 7.8% (0.17 × 103 km2) reductions in the unsuitable and less suitable zones, respectively, suggest that the planting areas of machine-picked cotton in both the less suitable and unsuitable zones, particularly with the existing regional planning, continue to demonstrate an irrational expansion. Therefore, to sustain Xinjiang’s cotton industry’s resilience and productivity, policymakers need to prioritize proactive land management and sustainable land allocation practices in response to changing climate patterns to optimize cotton production.

Impact of Climate Change on the Development of Viticulture in Central Poland: Autoregression Modeling SAT Indicator

Ongoing climate change is having a profound impact on agriculture, which is attracting attention from the scientific community. One of its effects is an increase in average temperature, which is a key factor in grape cultivation. This may increase the popularity of viticulture in central Europe. The aim of this study was to assess the potential for the development of viticulture in central Poland based on SAT changes from 1975 to 2021, in addition to changes in evapotranspiration, occurrence of late spring and early autumn frosts and frosty days in selected years from this period as an important factors relating to climate change. The research utilized data obtained from the Institute of Meteorology and Water Management—National Research Institute. The Bai–Perron test was used to determine the direction of temperature changes. An AR(1) autoregression model was used to predict SAT changes in central Poland for the years 2022–2026, based on the results of the Bai–Perron test. As part of the in-depth research on the SAT index, reference evapotranspiration calculations were also made as a second factor that is considered an important indicator of climate change. The Sum of Active Temperatures from 1975 to 2021 in the provinces of central Poland showed an increasing trend of 0.07% per year. The average SAT in central Poland in 2022–2026 is expected to range from 2700 °C to 2760 °C. Considering the current thermal conditions in central Poland and the forecasts for the coming years, it can be expected that vineyard cultivation will develop in this region. However, the research shows that the observed increasing trend in evapotranspiration, both in total in individual years and in the period of the greatest vegetation, i.e., in the months from May to the end of August, will result in an increasing need in central Poland to ensure adequate irrigation in developing vineyards.

Seed productivity of rod-shaped millet depends on ripeness groups of varieties

Seed productivity of rod-shaped millet depends on ripeness groups of varieties

Meteorological conditions for growing promising grape cultivars in the Black Sea agroecological zone of viticulture

Background. The pattern and duration of the grape plant growing season depends both on biological characteristics of plants and the environmental conditions of their habitat. Studying meteorological conditions and their effect on the growing phases of grape cultivars of different origin is important to optimize the deployment of these cultivars.Materials and methods. Eight introduced and domestic grape cultivars served as the research material. Phenological observations were carried out according to M. A. Lazarevsky, ANOVA was performed according to B. A. Dospekhov, the dependence of the duration of growing phases on weather conditions was assessed using pairwise correlations, and Student’s t-test was applied to determine statistical significance. Meteorological data were taken from the agrometeorological bulletins for Krasnodar Territory. The studies were conducted in the period from 2018 to 2021 under the agroecological conditions of the Black Sea viticulture zone.Results. Specific features of the temperature regime for grape growing phases in the environments of the Black Sea viticulture zone were ascertained. Indicators of heat supply and duration of the growing season according to Lazarevsky were used to identify the studied cultivars as early (‘Podarok Dmitriya’, ‘Reliance’, ‘Brigantina’ and ‘Anapskiy Ranniy’), medium (‘Concord’ and ‘Venus’), mid-late (‘Prikubanskiy’), and late (‘Kyoho’) genotypes. The sum of active temperatures required for the growing season of early cultivars was 2522–2603°C, for medium ones 2755–2760°C, for mid-late ones 2835°C, and for late ones 2970°C. According to the international classification, ‘Podarok Dmitriya’, ‘Reliance’, ‘Brigantina’ and ‘Anapskiy Ranniy’ are early, ‘Concord’, ‘Venus’ and ‘Prikubanskiy’ are mid-early, and ‘Kyoho’ is medium-ripening. All cultivars had a close direct relationship between the duration of their growing phases and the sum of air temperatures above +10°C.

Spatiotemporal Variability of the Bioclimatic Potential in the Central Chernozem Region

This article examines the bioclimatic potential (BCP) (according to S.A. Sapozhnikova) and agroclimatic characteristics of the Central Chernozem Region, including the Oryol oblast, with spatiotemporal trends of their variability analyzed from 1980 to 2021. In the early 2000s, compared to the late 20th century, there was a 10% increase in the BCP, a 13% rise in the sum of active temperatures, and a 6% longer active growing season. Furthermore, shifts in the isolines of the sum of active temperatures and the hydrothermal coefficient (HTC) occurred. The active temperature isotherm of 3000°C moved northward, and it is now running through the Belgorod and Voronezh oblast. As a result of the observed hydrothermal conditions, a significant part of the Central Chernozem transitioned from the zone with sufficient moisture (1.3 ≥ HTC > 1) to an arid zone (1 ≥ HTC > 0.7). The overall growth of the BCP in the Central Chernozem Region can be associated with a considerable rise in the sum of active temperatures and a reduction in moisture supply.

Agrobiological substantiation of growing Hungarian vetch in mixed crops

The production of high-protein feed stays an integral part of the development of feed production. The purpose of this study was to investigate the biological characteristics of Hungarian vetch when grown in agrophytocenoses using different types of winter cereals. Changes in the chemical composition of dry matter at different microstages of growth and development were studied, and the influence on the yield, nutrient content, and digestibility of plant material was determined depending on the stages of growth and development. The study was conducted using field, laboratory, laboratory-field, and statistical methods. It was found that to reach the full flowering phase, the sum of active temperatures should be 754°C, with precipitation of about 100 mm and daylight hours of 973 h. Observations of the growing season indicate the relationship between plants and the environment, which is important to consider when growing Hungarian vetch. Vetch plants reach a height of 100-104 cm in conditions of excessive moisture. The phytocoenotic balance of such mixtures, specifically vetch of the Orlan variety and winter triticale of the Bozhych and Bohodarske varieties, ensures sustainable productivity and nutritional value of plant material. The best harvesting time for high quality vetch is from the beginning to the middle of flowering, which ensures a crude protein content of 17-20% in dry matter. The effectiveness of mixed phytocoenoses has been confirmed by ecological tests of crop combination models in different soil and climatic zones of Ukraine, where yields of 36.2-51.8 t/ha of green mass and 7.1-11.5 t/ ha of dry matter were obtained over the years of use. The creation of a mixed crop allows producing high-quality plant material that is superior in energy and protein content to conventional vetch and oat mixtures. It was recommended to create such mixtures by sowing 2.5 mln/ha of cereal and 2.1 mln/ha of leguminous components after applying N45P45K45 to form a crop with high digestibility and nutrition. The system of mixed cropping of Hungarian vetch is promising for the production of silage and high-quality haylage in the face of climate change and as a precursor for post-cutting sowing of maize or sorghum crops

Influence of Weather Conditions in the Northwestern Russian Federation on Flax Fiber Characters According to the Results of a 30-Year Study.

Weather has significant impact on plant growth and development. It is important to analyze the influence of changing climate conditions on the expression of plant agronomic characters. Two flax varieties were grown from 1987 to 2018 in the Northwest of Russia. Weather conditions and their influence on flax agronomic characters were analyzed using the variance and correlations analyses. Significant influence of conditions of a particular year on the manifestation of all evaluated characters was revealed. Starting from June, high temperatures accelerate plant development at all stages. Prolongation of the germination-flowering period is most important for improving fiber productivity, while fast ripening in hot weather after flowering is preferable for the formation of high-quality fiber. Such data give a possibility to predict the yield amount and quality. The use of weather conditions data also makes possible a comparison of the results obtained in different years. The suggested method of classifying meteorological conditions of a year can be used in other genebanks for systematizing and analyzing the results of crop evaluation in the field. The correlation analysis revealed 3 correlated pleiades, namely (1) of productivity, (2) of fiber quality and yield, and (3) of the growing season phase durations, the sums of active temperatures and precipitation during each period. The great influence of growing conditions on the economically valuable traits indicates the necessity of searching for genotypes with stable character manifestations for breeding new varieties with stable yields and good fiber quality.

Changes in regional climatic characteristics in the Non-Chernozem zone of the Russian Federation and their impact on soybean yields

The work analyzes agroclimatic resources in the Non- Chernozem zone of Russia for the period from 1981 to 2023. As a result of studying the data array, it was established that the values of the sum of active temperatures in the agroclimatic subzones of the Non-Black Earth Region increased by 200-250°C, the amount of precipitation falling during the growing season decreased by 20-40 mm, the hydrothermal humidification coefficient (HTC) of Selyaninov decreased by 0.1- 0.3 p. The changes led to a shift of the isotherm of the sum of active temperatures by 150-200 km towards high latitudes. A grouping of years of research was carried out according to the hydrothermal coefficient, the yield and growing season of soybean variety Georgia were determined. As a result of the research, it was revealed that the highest average seed yield for the group of years (moistening conditions) was obtained in the year with sufficient moisture and amounted to 2.47 t/ha, and the lowest - 1.18 t/ha per year with insufficient moisture. A significant relationship has been established between seed yield, the weight of 1000 seeds and the HTC of the growing season: the variation in soybean yield during the years of research is 63% associated with the influence of factors: the weight of 1000 seeds and the HTC of May-August (R2 = 0.63). Thus, the recorded upward trend in the sum of active temperatures in the region for the crop is positive and contributes to the expansion of soybean crops in the Non- Chernozem zone of the Russian Federation.

Climate warming disturbances periodicity of Siberian stone pine seed production (Pinus sibirica Du Tour)

Siberian stone pine is one of the main edificator plants of taiga forests of Western Siberia. Sustainable functioning of forest ecosystems depends on its successful cone crops, as its seeds are the basis for the diet of many forest animals. A cone crop in this species is characterized by pronounced interannual variability, manifested in the formation of high seed yields once in 3-4 years. However, in the last 20 years, high yields have been rare, replaced by years with average and low yields. To establish the reasons for these changes, the dynamics of seeding in the period from 1990 to 2023 and weather conditions in spring in the pollination year during the same period were analyzed. It was found that the number of mature cones in the crown largely depended on spring weather in the year of pollination and was negatively correlated with the sum of active temperatures above +5°C accumulated before the late spring frost. If frost occurred at SAT above 300°C, the following year’s crop was minimized. Analysis of weather conditions showed that, on average, there is a tendency to shift the dates of the last frosts to later dates, and even a short-term decrease in temperature to -1 °C leads to complete death of the future crop of cones. Despite the growth of heat availability in the spring period due to active temperature increase in April, the expected shift of frosts to earlier dates is not observed in the south of Western Siberia. For Siberian stone pine, such situation is fraught with strengthening of negative trend in seeding dynamics. It is supposed that at further climate warming the beginning of spring development of reproductive structures will occur at earlier dates, so reproductive structures will be more damaged by late spring frosts, since the latter remain within the same time frames.

Ecological preferences of the Swiss pine (Pinus cembra L.) forests in the Gorgany Nature Reserve

Swiss pine (Pinus cembra L.) is a montane Carpathian (Alpine-Carpathian) species. The modern distribution of the Swiss pine is disjunct, the two isolated areas are located in western and central Europe (Alps) and the middle and high mountains of the Carpathians. The largest areas of Swiss pine in Ukraine are preserved in the Gorgany region at the altitude of 1250‒1450 m above sea level, where it forms the upper forest line. In the Gorgany Nature Reserve, P. cembra grows in the altitude range from 1070 to 1475 m ASL. The lower boundary, in the form of individual trees, descends to 1000 m ASL, and the upper boundary rises to 1585 m ASL. To define the ecological preferences of the Swiss pine, a series of route surveys were conducted and research sites (permanent forest monitoring plots, stationary research profiles, and stationary areas for the counting of natural forest regeneration) were established. The study of the plant communities with P. cembra on the southwestern slopes of the Dzhurdzhi tract showed the dependence of the forest species composition on the altitude above sea level. The forest stands quantitative composition and productivity are also significantly influenced by slope exposure. The proportion of P. cembra in the forests on steep slopes (30‒55°) of west and north-west exposure is relatively high (from 17.1% to 49.0%). Under other conditions, the proportion of P. cembra in the stand composition gradually decreases. Swiss pine is almost completely absent on the slopes of eastern and northern exposures except for rare single trees in Pinus mugo Turra scrub on northern slopes. The forests with P. cembra are typical of sunny slopes where the available sum of active temperatures ranges between 1000° and 1400° and the average ambient temperatures from -12.2°С to +16°С. The optimal environmental conditions for the relict species P. cembra in the Dovbushanski Gorgany region are on the western slopes with a steepness of 17‒55° and southwestern and northwestern slopes with a steepness of 35°‒42°. In terms of soil fertility, oligotrophic edaphotopes with moderate moisture are optimal for the growth of Swiss pine.

COMPARATIVE ASSESSMENT OF THE PRODUCTIVITY OF AGROPHYTOCENOSES WITH PEAS DEPENDING ON HYDROTHERMAL RESOURCES

In the soil and climatic conditions of the Right-Bank Forest-Steppe, regardless of the influence of abiotic and biotic factors, high adaptability of annual agrophytocenoses of spring oats and spring triticale with seed peas was established during the growing season. It is important to note the response of oat and pea plants to changes in moisture supply and temperature during the growing season, provided that the biological characteristics of the crop are maintained, to form an average yield of dry matter and digestible protein within 5.81 and 0.619 t/ha over 24 years of observations, respectively. During the long-term research period, the sum of active temperatures was 874 oC, precipitation was 124 and the hydrothermal coefficient was 1.46. Long-term studies have shown that during the formation of vegetative mass by agrophytocenoses (May-June), the distribution of precipitation was uneven against the background of an increase in the average monthly air temperature, which was reflected in the yield of dry matter and its quality. During the 10 years of research, the highest amount of precipitation was observed - 159-204 mm. The most critical period for growth processes and crop formation was 1999, 2003, 2004, when 37-53 mm of precipitation fell with the sum of active temperatures of 762-880 mm and the GTC of 0.46-0.69. Over the past 9 years (2011-2019), the temperature has increased to 1021°C. Comparing the fodder productivity of binary mixtures of annual crops, it can be stated that with early spring sowing, the yield of fodder units and crude protein in fodder oats was higher compared to spring triticale. This is primarily due to the biological characteristics and duration of the vegetation period of the studied crops, which in spring triticale, unlike oats, the earing phase occurs 8-10 days earlier. The research gives grounds to conclude that it is agrobiologically expedient to use binary grass mixtures with different types of cereal crops in the raw material conveyor. The use of cereal crops that mature at different times ensures the production of plant material for harvesting fodder (green mass, silage, hay or haylage from dried grasses) between the first and second mowing of perennial grasses. In particular, it is also important to note that biological groups of plants effectively use agrometeorological resources during the stages of organogenesis, forming a sustainable crop with high quality indicators. Based on the data obtained, it is possible to predict the productivity of annual agrophytocenoses for the following years.

Продуктивность перспективных сортов вишни (Prunus cerasus L.) в условиях южного садоводства

Abstract. The features of the implementation of the production potential of cherry varieties in the conditions of southern horticulture are presented. The studies were carried out in the conditions of the Prikubanskaya fruit growing zone of the Krasnodar Krai in 2016–2022. The objects of research were 7 varieties of common cherry of various origins. The purpose of the research was to study the productive potential of cherry varieties and its main components, depending on the negatively changing environmental conditions. Methods. The research was carried out according to the “Program and methodology for the variety study of fruit, berry and nut crops” and “Program and methodology for the selection of fruit, berry and nut crops”. Statistical processing of the obtained data was carried out according to the method of B. A. Dospekhov. The studies were carried out using generally accepted and standard methods. The scientific novelty of the research lies in the identified patterns and features of the implementation of the production potential of cherry varieties in unstable environmental conditions and the impact of stress factors. According to the results of the research, early-fruiting varieties of cherries, Prizvanie and Ivanovna, which begin to bear fruit 2–3 years after planting, have been identified. It was found that the average fruit weight of the varieties varied from 2.98 to 6.38 g, depending on the biological characteristics of the variety and the conditions of the year. Large-fruited varieties with a fruit weight exceeding 5 g have been identified: Prizvanie (5.38 g), Timati (5.43 g), Ivanovna (6.38 g) and Khodosa (6.33 g). It was found that the yield also varied depending on stress factors and the degree of adaptability of varieties to them. Stably fruitful and high-yielding cherry varieties Ivanovna and Khodosa were identified, the average yield of which was 15.7 kg/tree. or 10.5 t/ha. It has been established that the dependence of the yield of cherry varieties of different origin on average annual temperatures is average (r = 0.65), on the sum of active temperatures – average (r = 0.37) and on the sum of precipitation – strong (r = 0.87). To create highly productive cherry plantations in the conditions of southern gardening, varieties Ivanovna and Khodosa are recommended.

The effect of sowing dates on a vegetation period of spring wheat varieties of different maturity groups

The purpose of the current work was to estimate the effect of sowing dates on a length of a vegetation period and the sowing qualities of spring wheat varieties of different maturity groups. The trials were carried out from 2018 to 2020. There have been studied such six varieties as middle-early varieties ‘Altaiskaya 70’, ‘Novosibirskaya 29’, ‘Tulunskaya 12’, Krasnoyarskaya 12, the middle-maturing variety ‘Kuraginskaya 2’, the middle-late variety ‘Svirel’. There have been studied such two sowing dates as optimal in May 15, and late in May 22. The sowing trials were carried out with a seeder SSFC – 7. Harvesting was carried out with the combine ‘Hege’. The grain was dried, cleaned on ‘Petkus’, and weighed. The germination was estimated according to GOST 12036-66. Grain crops were sown in weedfree fallow. The counting area of the plots was 10 m2, with three repetitions. When sown in late dates, the ‘sprouting-ear formation’ period reduced on 4 days for the middle-late wheat variety ‘Svirel’, on 2 days for the middle-maturing varieties ‘Kur aginskaya 2’ and ‘Krasnoyarskaya 12’, for the middle-early varieties ‘Altayskaya 70’, ‘Tulunskaya 12’, ‘Novosibirskaya 29’ this period did not change. The length of the period ‘ear formation-maturity’ period for middle-early wheat varieties was 34–36 days, for middle-maturing varieties it lasted 36 days, and for the middle-late variety ‘Svirel’ it was 40 days. The varieties ‘Tulunskaya 12’, ‘Novosibirskaya 29’ and ‘Altaiskaya 70’ increased their productivity on 0.2–0.6 t/ha at a late sowing date, the middle-maturing varieties ‘Kuraginskaya 2’, ‘Krasnoyarskaya 12’ and the middle-late variety ‘Svirel’ increased their productivity on 0.3–0.5 t/ha at an early sowing date. There should be noted that 1000-grain weight changed similarly to the productivity of varieties. This indicator of the middle-early varieties increased in the late sowing date, and that of middle- and late-maturing varieties in the early sowing date. The recommended period for sowing spring wheat in the conditions of the Krasnoyarsk Territory for middle-early varieties for seeds is the beginning of the third ten days of May with a sum of active temperatures of 190 °C; for middle- and late-maturing varieties it is the middle of the second ten days of May at a sum of active temperatures of 150 °C.

ПОЯВЛЕНИЕ И РАЗВИТИЕ ВИНОГРАДАРСТВА В НАУРСКОМ РАЙОНЕ ЧЕЧЕНСКОЙ РЕСПУБЛИКИ

The article is devoted to the Naur region as the main producer of grapes during the heyday of the wine-growing industry of the Chechen Re-public in the last century. Having no historical roots associated with the cultivation of grapes, this area gave a powerful impetus to the devel-opment of the sector on an industrial basis. It became the largest area of sheltered viticulture in Russia. The article shows the main stages of this process. The main factors that led to this result are analyzed. In particular, it was revealed that certain circumstances contributed to origin and development of viticulture and winemaking. First, relatively favorable soil and climatic condi-tions. The area is located in the northern part of the republic, and occupies a relatively narrow strip along the left bank of the river Terek, cap-turing the floodplain of the river and adjacent to the Tersko-Kumsky sandy massif, with poor sandy and sandy soils. Such soils are suitable for the cultivation of grapes. Secondly, the sum of active temperatures here is higher than in other regions of the republic, which makes it possible to obtain high quality products. Third, the mixed population − the Terek Cossacks and the Che-chens resettled from the mountains. They learned from each other and were employed thanks to a highly efficient and labor-intensive culture. The state correctly assessed the possibili-ties of the region and created the appropriate conditions for the development of the industry. Here, for the first time, specialized viticulture farms with wineries (wine centers) were created, which were advanced agro-industrial associa-tions. The industry was also lucky with talented specialists, production organizers, winegrowers and winemakers. Based on the study, a conclu-sion is made about the possibility of reviving the viticulture industry in the region, using historical experience.

Influence of weather conditions on yield and protein content in winter wheat grain

The results of three-year studies (2020–2022) conducted in the forest-steppe zone of the Samara region in the agrocenosis of winter wheat are presented. The purpose of the work was to study the influence of natural and climatic conditions of the research area on the formation of yield indicators, protein content in winter wheat grain. The material was 10 varieties from the Vavilov All-Russian Institute of Plant Genetic Resources (VIR) collection and 5 varieties of selection of the Povolzhsky Scientific Research Institute of Selection and Seed Growing named after P.N. Konstantinov. Yield, grain protein content and protein yield per hectare were determined. Varieties characterized by high yield and high amount of protein in grain, showing maximum protein yield in different weather conditions of the years were identified. Over the years of research, the year 2022 was the most favorable for the formation of high yields (between 6 and 8.5 t/ha were harvested in the indicated year), where a large amount of precipitation was observed in May – the first ten-day period of June. The protein content in grain was the highest in 2021 (14–19%), when high temperatures were observed during the grain filling period in the absence of precipitation. For each variety, the correlation dependence of the sum of active temperatures and the amount of precipitation during the spring-summer vegetation period with the studied indicators was established. There was a negative correlation between the sum of active temperatures and yield (from –0.553 to –0.981) and a positive correlation with the protein content indicator (from 0.605 to 0.984) depending on the variety. The amount of precipitation was in a positive correlation with the yield index, the dependence on the protein content in the grain was ambiguous and depended on the variety. The studied indicators were influenced not only by natural and climatic conditions, but also by the genotypic features of the studied varieties, which explains the diverse correlation dependence.

Phenological assessment of early-maturing soybean accessions (Glycine max (L.) Merr.) under the conditions of Moscow Province

Background. The range of early-maturing cultivars suitable for the Non-Black-Earth Zone of the Russian Federation (RF) is extremely limited. The main method of finding sources of earliness for crop production and breeding is the evaluation of the gene pool under the required conditions.Materials and methods. The objects of the study were 81 soybean accessions from the VIR collection, precharacterized as early-ripening under the conditions of Northwest Russia. The studies were carried out in 2018–2020 as field trials under the conditions of Moscow Province.Results. Soybean accessions were characterized by the duration of the emergence-to-flowering (37–53 days), flowering-to-ripening (50–85 days) and emergence-to-ripening (81–130 days) periods. The extreme ripening dates for the accessions were observed from August 20 to October 5, while the maximum duration from emergence to ripening was from 93 to 139 days. The highest sum of active temperatures above 10°C for a growing season ranged from 1642 to 2189°C. Most of the studied accessions were characterized by a short emergence-to-flowering period. Therefore, the differences among accessions in the duration of the growing season were mainly due to the different lengths of their flowering-to-ripening period.Conclusion. Soybean seeds should ripen no later than the first 10 days of September for a stable harvest under the weather conditions of the Russian Non-Black-Earth Zone. There were 32 accessions from breeding centers of the RF, Belarus, Poland, Germany, Sweden, and the U.S. that met these requirements during the three years of observations. The selected accessions demonstrated a short emergence-to-flowering period of 37–48 days, and the length of their flowering-to-ripening period of 50–66 days, on average for three years. They can be used as sources of earliness in soybean breeding.

Слагаемые продуктивности сортов яровой пшеницы

Abstract. Each soil-climatic zone should be provided with the most adapted varieties of agricultural crops. The Middle Cis-Urals is characterized by a short growing season, low-humus acidic soils. However, due to global warming, the sum of active temperatures in the region exceeded 2000 °C and made it possible to grow not only early-ripening, but also mid-ripening varieties of spring wheat, which have a greater productivity potential. The purpose of the study is a comparative assessment of spring wheat varieties of different ripeness groups according to the nature of the development of the above-ground mass, the formation of yield and its components. Methods. Zonal tests were carried out for three years on acidic soddy medium podzolic medium loamy soil. We tested 10 varieties of early, mid-early and mid-ripening groups. The field experience had accounting plots with an area of 1.05 m2 and their sixfold repetition. Results. It has been established that the mid-early varieties Omskaya 36 and Kalinka, as well as the mid-ripening varieties Simbirtsit, Likamero and Chernozemnouralskaya 2, significantly exceeded the yield of the early ripe variety Irgina by 13, 20, 15, 13 and 31%, respectively. In addition, varieties Chernozemnouralskaya 2 and Kalinka showed an average variation in yield (V = 12.5 and 19.7 %, respectively). The mid-ripening varieties Simbirtsit, Likamero and Chernozemnouralskaya 2 compared with the Irgina variety had a significantly lower straw content ratio by 18, 29 and 17 %, respectively. The variety Chernozemnouralskaya 2 stood out among other varieties in coefficient of productive tillering, exceeding the Irgina variety by 15.5 %. Varieties Kalinka and Simbirtsit had a greater mass of 1000 grains, respectively, by 3.9 and 3.0 g than that of the Irgina variety (27.7 g). The scientific novelty of the conducted research lies in the comparative assessment of the formation of yields by spring wheat varieties of different ripeness groups on acidic low-humus soil.

Association of hydrothermal conditions one month before harvest and degree of maturity with the yield of sound apple fruit aft er storage

The quality and storability of apple fruits depend on the apple variety and degree of maturity, as well as weather conditions of the growing season. For each pomological variety, the picking maturity of the fruit is individual. It depends on geographical and climatic area of cultivation, weather conditions of a particular season – the hydrothermal conditions of the active growing season (the sum of active temperatures, precipitation and hydrothermal coefficient (HTC)). Fruits should be harvested at the optimal maturity stage to ensure maximum duration of storage and preservation of fruit quality. The paper presents a quantitative assessment of the impact of weather conditions one month before harvesting in different years (2014, 2016, 2018, 2019) on the yield of sound apple fruits of Priokskoye and Rozhdestvenskoe breeding varieties (the Russian Research Institute of Fruit Crop Breeding) after storage at +2 °С. A certain regularity was revealed in the yield of marketable fruits after storage, depending on hydrothermal conditions, 30 days before harvesting. Regression equations for Priokskoye and Rozhdestvenskoye varieties grown in central Russia were obtained on the basis of HTC indicators and the joint effect of the sum of active temperatures ≥ 10°C and HTC. The equations can be used to predict the yield of sound fruits after storage, by interpolating and extrapolating empirically obtained data.

ДОЛГОВРЕМЕННЫЕ ИЗМЕНЕНИЯ ХАРАКТЕРИСТИК ВЕГЕТАЦИОННЫХ ПЕРИОДОВ В ПРЕДУРАЛЬЕ В СВЯЗИ С ИЗМЕНЕНИЯМИ КЛИМАТА

The peculiarities of the variations in the growing season characteristics in the Cis-Ural region over the 20th and early 21st centuries were studied. The information on average daily air temperature and precipitation at four weather stations was used. It was found that, against the background of a general increase in air temperature, there was a positive trend in the length of growing seasons due to the changes in the dates of spring warming and autumn cooling. Starting from 1936, three periods of changes in the growing season length were revealed, and the last one, which started in 1990, has been the longest. The sum of active temperatures, as well as total precipitation, insignificantly changed during the study period, which was confirmed by a small positive trend. The average daily temperature in growing seasons has almost not changed over 85 years. The comprehensive assessment of the weather conditions affecting the growth of grain crops was performed based on the analysis of the hydrothermal coefficient. The coefficient was used to estimate the frequency of droughts having different intensity. Some increase in the coefficient, as well as the positive trends in the amount of precipitation (especially in the Perm krai), indicate the improvement of the conditions for spring grain crop cultivation in this part of the Cis-Ural region.