Decade Of June Research Articles

Characterization of the starting conditions of the rainy season in Senegal: highlighting the constraints of crop establishment

The start of the rainy season in Senegal is characterized by critical variability, resulting in many crop failures after seed planting when a long dry spell occurs. The objective of this study is to characterize the starting conditions of the rainy season in different areas of Senegal in relation to crop success at the early stage. An analysis of four seasonal components determined from a daily rainfall database of 95 stations from 1950 to 2015. These seasonal components are the sowing date (Sowing), the Onset of the rainy season date (Onset), the length of the longest dry spell (DryMax), and the total rainfall (TotRain) during the 30 days after sowing. Statistical methods of time series homogeneity determination such as the Pettitt test, the Buishand test, the Von Newmann test, and the segmentation method have been applied to determine actual breakpoints and to obtain the most recent and homogeneous period to define the component in each site. The results indicate that these components have not exhibited statistically significant changes since 1950. Indeed, 3% of the stations show breakpoints for the Sowing, 4% for the TotRain, and 2% for the Onset. The start of the season follows a South East-North West gradient. It begins in the extreme South-East part of the country in the second decade of June while the first waves of sowing take place in the South-East center part from the second half of June. The north zone remains exposed to false start events with important seasonality. In the Northern and Central zones, the early or late character of the sowing passes more on the DryMax than the TotRain. It would be interesting to elucidate the effects of the rainfall regime at the early stage on the rainy season profile to gain better control of the pluvial crop yields.

Invading the North: Dispersal of Nearctic treehopper Stictocephala bisonia (Hemiptera: Cicadomorpha: Membracidae) in European Russia

In recent years, the problem of distribution and expansion of new territories by invasive species has become global. The publication analyses the current distribution of Nearctic treehopper Stictocephala bisonia in the European part of Russia. It is a North American species which was introduced into Europe over 100 years ago, but only in the last 20-30 years has it been actively spreading in the continent. In the European part of Russia, the Nearctic treehopper has been known since 1992 from the Rostov region and since 1996 from the Krasnodar Krai. At present the species is reliably registered in 26 regions. The major part of observations (185, 82.2%) is made in the period from 2020 to 2022. Currently, the northern border of distribution is the city of Nizhny Novgorod. In the northeast, the range of the species reaches the Republic of Tatarstan, to the east of the Republic of Tatarstan and the Republic of Bashkortostan, the hopper has not yet been observed. Imagoes are observed in the southern regions beginning in the third decade of June. The maximum number of observations falls on the second and third decade of July and August.

Похід Максима Кривоноса у Поділля й Південно-Східну Волинь та його воєнно-політичні наслідки (червень-липень 1648 року).

The purpose of the article is to find out the biography of Maksym Kryvonis at the beginning of the Cossack uprising of 1648, the campaign on the territory of Podillia and South-Eastern Volyn, its course, military actions, the political self-awareness of the participants of the expedition and its consequences for the development of the Ukrainian National Revolution in the summer of 1648. The methodological foundation is based on the concepts of the "Annals" and "New Social History" schools, as well as the principles of historicism, objectivity, reliance on historical sources, systematicity, and comprehensiveness. The main research methods were narrative, reconstructive, chronological, comparative, historical-genetic, and synchronous. The scientific novelty lies in an attempt for the first time in historiography to reconstruct a complete picture of the liberation campaign of M. Kryvonis in Podillia and South-Eastern Volyn, the program requirements of its participants, and the military-political consequences for the development of the revolutionary struggle in the summer of 1648. Conclusions. The study of the discovered complex of sources and scientific literature gives reason to see M. Kryvonis as an outstanding leader of the national liberation, religious and social struggle of the population of Right-bank Ukraine, which began to transform into the National Revolution. The campaign began at the end of the first decade of June with his capture of Pogrebyshchi and ended at the end of July with B. Khmelnytsky’s recall to his camp. It went through two stages in its development: the 1st (approx. June 7-8 - early July) was marked by successful military actions with Polish hostages in the cities of Bratslav Region and the liberation of its territory from Polish rule; The 2nd (beginning of July - end of July) was mainly characterized by the struggle with magnate and government units, which ended with the successful battle of Starokostiantyniv on July 26-28, the retreat of the troops of Prince I. Vyshnevetskyi and the liberation of the territories of Southwestern Zhytomyr region and Southeastern Volyn. Thanks to his military and organizational talents, M. Kryvonis managed to transform the 400-th Cherkasy regiment at the beginning of the campaign into a 28-30-thousand-strong army at the time of its completion. Fully sharing the revolutionary sentiments of the Cossack commoners, who sought liberation from national-religious oppression and social subjugation, to achieve personal freedom, land ownership, and independence of Russia ("on the Vistula") from the Polish Crown, he became the informal leader of a radical group of elders, which transformed into the Ukrainian political proto-elite.

Розвиток ринхоспоріозу та його шкідливість на посівах ячменю озимого в умовах західного лісостепу

The article presents the results of research on the development of rhynchosporiosis on winter barley varieties: Zbruch, Valkiria, Snihova koroleva, Dostoinyi, Status, Darii on a natural background in the conditions of the Western Forest-Steppe. It has been established that the development of this disease depends on weather conditions, vegetation phases of the culture and variety. During 2021–2023, in the phase of emergence into the tube, the lesion was 0.5–5.0%, in the ear phase – 1.0–7.0%, in the milk ripeness phase – 13.5–35.0%. The lowest development of the disease was noted in the following varieties: Snihova koroleva (14.7%), Valkiria (14.7%), Status (14.2%). The species composition of rhynchosporiosis is presented by the causative agent Rhynchosporium graminicola Heinsen. Taking into account climate changes, the development of this disease on the studied varieties increased in 2023 compared to previous years. The appearance and development of rhynchosporiosis on winter barley is facilitated by the increased amount of precipitation in the third decade of May and the first decade of June (Hydrothermal moisture coefficient was 1.4 and higher). It should be noted that damage to winter barley by this disease affects the length of the ear, the number of grains in it, the weight of the grain in the ear and the weight of 1000 grains. The coefficient of harmfulness, depending on the level of development of the rhynchosporiosis, was in Zbruch 0.24–0.38%. The higher the development of the disease, the higher the coefficient of harmfulness was. Thus, with 50% development of rhynchosporiosis, the harmfulness coefficient was 0.3; and with 75%, respectively, 0.36; at 90% – 0.38. With 90% disease development, there was a decrease in the number of grains by 5.1 pcs. compared to healthy plants. The mass of grain in an ear decreased by 0.16 g, the mass of 1000 grains decreased by 3.4 g.

Monitoring of phytophages in spring wheat agrocenoses in view of applying different agrotechnological methods in the conditions of the North-East of Kazakhstan

The article discusses issues related to the impact of agrotechnical practices (sowing time and preceding crop) on the number and species diversity of pests in spring wheat varieties of foreign and Kazakhstan breeding in the conditions of the North-East of Kazakhstan. In order to increase plant resistance to pests and identify the impact of various preceding crops the research in 2022 was conducted in agricultural organizations located in the regions of North-Eastern Kazakhstan. The spring and summer of the vegetation period of 2022 were characterized by high temperatures and a lack of moisture in the soil, impact of which is seen in the form of turgor decrease in plant organisms and their resistance to various damages. In the course of early sowing of Triso wheat, the plants were more affected at the initial stage of development by the lack of moisture in the soil and high temperatures, which identified in the form growth retardation and increased plant susceptibility to pest damage. The sowing of other varieties was carried out at the optimal time recommended by the scientific institutions of the region ― in the period of May 15‒24. This allowed the culture to develop normally and avoid the most vulnerable phases during the maximum level of summer precipitation, which is typical for North-Eastern Kazakhstan in the third decade of June. The practical significance of the work is in the possibility of effective implementation of protective measures and optimization of the agricultural technology used in accordance with the soil and climatic conditions of crop cultivation and species diversity of phytophages.

Assessment the state of the omul stock <I>Coregonus migratorius</I> in the waters of Northen Baikal according to hydroacoustic investigations

Recently in Lake Baikal there was observed decrease in population of the most abundant species among commercial fish – Baikal omul (Coregonus migratorius). That is why restrictive measures have been imposed on its catches. A hydroacoustic method based on hydroacoustic surveys was used to assess the evolution of the Omul population during the period of restrictive measures in one of the most productive fishery areas – the Northen Baikal. This work represented the results of three-year hydroacoustic research (2021, 2022 and 2023) in the first decade of June. Taking into account the confidence intervals for estimating the number and biomass of Omul, the stock in Northen Baikal is quite stable. The omul spatial distribution on the investigated areas is also stable.

Species diversity and abundance of aphids in triticale crops in North-West Russia

The aphid complex of triticale crops in the Leningrad region was characterized by a large species diversity (20 species), but low abundance (1.6 specimens/trap), which, under the influence of weather conditions, varied 2.4–3.8 times depending on the crop. Winter triticale crops were inferior to spring triticale in terms of species diversity (9 vs. 18 species) and abundance of aphids (1.2 vs. 1.9 specimens/trap). The numerical majority were species whose food specialization is related to cereal vegetation (53.8%-71.4% of individuals). The mass species were Rhopalosiphum padi L. and Sitobion avenae F., which accounted for 25.7% and 23.0% of the total number of individuals. The presence of other aphid species in grain crops is due to the presence of weeds (25.7%-26.9% of individuals), the growth of other crops nearby (2.9%-10.3%), woody and shrubby vegetation (0%9.0%). The greatest species diversity and abundance of aphids in crops of both winter and spring triticale was noted in the second decade of June, when the stage development of the former corresponded to the earing phase, and the latter to the tube exit phase.

Использование жидких комплексных микроудобрений для роста и развития робинии псевдоакации и сосны крымской в засушливых условиях

The article presents data on the results of testing complex micronutrients when sowing seeds of Robinia pseudoacacia L. and Pinus nigra subsp. pallasiana (Lamb.) Holmboe. at a production nursery. Stratification provides seeds with rapid germination under optimal conditions of oxygen access and maintaining a humidity level and temperature of 10°C. Fertilizers “Volski Biochem” are able to increase the energy of germination of seeds of the studied species, increase their growth rate and contain all the necessary nutrients for plants. The highest content of trace elements is found in the preparation “Microel”. Established that the best option for planting seeds are RCL‑81 forest cassettes, which naturally and correctly distribute the root system of seedlings, increase their ability to form active root tips, provide oxygen to plants and eliminate waterlogging with improper watering. The percentage of safety for seedlings in the first and second year was almost the same. Pine seeds require de-spraying on the VSG‑01 air gravity apparatus before processing and planting. The possibility of using tools for tillage and crops is provided by an ordinary method with the location of narrow sowing lines along the tapes. Proven that the use of complex micro fertilizers allows pine and robinia seedlings to have an optimal ratio of the aboveground part and the root system, accelerated growth and development, and an even stem. The maximum growth of robinia was 71–98 cm, pine trees 10–29 cm, which fully met the standards and requirements for the cultivation of planting material of woody species. Revealed that the differentiation of robinia and pine seedlings in height begins in the second half of June, in the variant of the experiment with sowing seeds in a box, the largest gains of seedlings were observed in the third decade of June, after which there was a noticeable decrease in growth. As a result, the best growth and development indicators were observed in Crimean pine in the 1st variant of the experiment, in robinia pseudoacia in the 1st and 2nd variants. The growth rates of two-year-old seedlings of the studied species are identical to those of annual seedlings

USING BLACK WALNUT ROOTSTOCK FOR CREATING HIGH-YIELDING WALNUT PLANTATIONS

The comparative analysis of seed germination and growth of walnut and black walnut seedlings in the conditions of the Right-Bank Forest-Steppe of Ukraine was carried out. It was found that in rows with a sowing depth of 10 cm and 13 cm, the germination rate of walnut had the highest rates and amounted to 70% and 63%, respectively, and black walnut - 80% and 84%. The lowest germination rate was observed at a sowing depth of 17 cm for walnut and 6 cm for black walnut, 46% and 39%, respectively. The influence of the position of the walnut seeds on their germination was determined. In particular, when sown by the "top up" and "on the edge" methods, the germination rate was 70% and 72%, which is 24-26% higher than the "top down" and "side by side" methods. The germination energy of black walnut seedlings was found to be higher than that of walnut seedlings. The first signs of germination of black walnut were observed 7 days earlier than in field crops of walnut. It was found that the main growth of seedlings in height began from the end of the first decade of June and lasted until the first decade of August. The average height of black walnut seedlings was 50 cm, while the average height of walnut seedlings was 19 cm lower and amounted to 31 cm. The yield of standard black walnut seedlings was recorded at 69% of the total number of seedlings, while in walnut this figure was only 12%. The compatibility of the varieties 'Webu-6', 'Chandler' and 'Kazaku' with black walnut and walnut during the cultivation of grafted seedlings was studied. It was found that the selected experimental varieties of walnut, which were grafted onto black walnut seedlings, showed approximately the same formation of callus tissues, except for the variety 'Vebu-6'. This once again confirms the information that not all walnut varieties can participate in interspecific combinations. It was found that the length of the central root of the black walnut at the end of the first year of cultivation is 15 cm longer than the length of the central root of the walnut and averages 43 cm. The main branching of lateral roots in walnut occurs at a depth of 10 to 20 cm. The number of main skeletal roots is generally 3-4 units. At the end of the first year of cultivation, the seedlings had a significantly smaller root system compared to black walnut. The root system of standard black walnut seedlings is on average 60% larger than that of walnut. The main branching of lateral roots is on average at a root length of 7 to 30 cm. Similar to the walnut, the root system of black walnut has 2-3 tiers. The number of skeletal roots averages 8-10 pieces, and the length of the main skeletal roots ranges from 15 to 30 cm. According to the research results, it can be concluded that walnut seedlings grafted on black walnut seedlings have prospects for further introduction into production as they can bear fruit faster, have relatively restrained growth, allow for the formation of a crown at the 3rd year of life and have a more powerful root system.

'SAROM' ȘI 'IREAL', SOIURI NOI DE CĂPȘUN

Since 1980, the strawberry breeding program developed at the Research Institute for Fruit Growing Pitesti, Romania has released seven short-day cultivars of interest for temperate climate environments. The latest released cultivars, 'Sarom' and 'Ireal' are late cropping season ones (second decade of June) with large fruit size (more than 25 g) and total yield per plant of over 600 g. Fruits are firm flesh and excellent flavour. Plants have compact habit with high vigour, and fruits are well presented on long braces providing increased picking efficiency. They are characterized with high plant resilience to diseases and high fruit quality.

Monitoring of a <i>Cypripedium guttatum</i> (Orchidaceae, Liliopsida) population on the northern border of its distribution range (Komi Republic, European Russia)

The results of our 12-year study of a population of the rare orchid Cypripedium guttatum Sw. on the northern border of its range, on the territory of the Komi Republic (north-east of European Russia) are presented. Our research has shown that weather factors (temperature and precipitation) have an impact on the seasonal development of shoots and plant size. The number of shoots is influenced by the weather conditions of the previous growing season, namely: the temperature of the first decade of August influences positively while early autumn frosts and the amount of precipitation of the entire period do negatively. A negative correlation was found between the number of flowering shoots and the temperature of the second decade of July of the previous growing season and a positive relationship between the number of juvenile plants and the precipitation of August of the previous growing season. Fruit set was quite low (17.1%), which is typical for this species. The pollination efficiency of C. guttatum was negatively affected by the high temperature during its flowering (the second decade of June). One box contained an average of 4065 seeds. The real seed productivity per shoot varied from 1989 to 7064 pcs., it is associated with precipitation in the second decade of July of the current growing season. The high number of the population studied (25 thousand shoots), the correspondence of the ontogenetic spectrum to the basic one of the species, the annual presence of juvenile plants of seed origin indicates its stable condition.

THE TROPHIC RELATIONSHIP BETWEEN PARASITIC ENTOMOPHAGES (HYMENOPTERA: APHIDIIDAE) AND SPECIES OF APHIDS (HOMOPTERA: APHIDIDAE) TO THE WHEAT CROP

It was demonstrated that the aphid species Schzarium graminium and Sitobion avenae reached the highest degree of population density in the wheat crop in the first decade of June (18,0 and 16.6% respectively). It was found that aphids and entomophages reached the highest degree of development when the gray crop entered the phenological phase of buttoning. Thus, the population density of aphids was 23,0 % and that of entomophages – 16,0%. 6 species of natural entomophages were highlighted (Aphidina evri Haliday, 1834; Ephedrus sp.; Lysiphlebus sp.; Diaeretiella rapae M. Intosh, 1855; Praon volucre Haliday, 1833; Ephedrus persicae Froggatt, 1904), which can control the population density of of the 3 most widespread species of aphids (Schzarium graminium L.; Sitobion avenae F.; Myzodes persicae Sulz.) in the wheat crop.

Feeding conditions of the interspecific bumblebee association (Hymenoptera, Apidae, <i>Bombus</i>) in the central forest-steppe of the Omsk Region

This article reports that the main food plants of bumblebees of the interspecific association of the central forest-steppe of the Omsk Region during the period of flight activity (I decade of May – III decade of September) are 120 plant species from 30 families. Common and fairly common species predominate, which, under the condition of medium, high and superfroductivity, form the forage base. All rare, quite rare, very rare, as well as unproductive common and unproductive fairly common plant species perform a supporting function in the nutrition of bumblebees. At the beginning of the flight activity of bumblebees, low and medium-productive species predominate, then after the beginning of flowering of new species, highly and super-productive ones are included in the feed spectrum – there is a change in food conditions from unfavorable to favorable. During the main flight period, bumblebees feed or forage on 99 plant species, among which fairly ordinary medium-productive species predominate. Before the second decade of August, three peaks in the expansion of the food spectrum were revealed: in the third decade of May (by 15 species), in the second decade of June (by 31 species) and in the second decade of July (by 20 species). The exclusion of plants from the bumblebee diet occurs every decade. The greatest peaks were recorded in the II decade of July and in the III decade of August – by 21 species. Starting from the first decade of September, there is a change in food conditions from favorable to unfavorable. In general, the feed base of bumblebees of the interspecific association of the central forest-steppe of the Omsk Region has a stable character and allows to provide bumblebees with a sufficient volume of full-fledged feed.

Features of the vital activity of cereal aphids in the North-West of Russia

The publication presents data on long-term monitoring of the dynamics of the number of cereal aphids on spring grain crops in the Pushkinsky district of St. Petersburg and the Tosnensky district of the Leningrad region. The appearance of winged parthenogenetic females in the fields in the biotope of grain crops was noted in the first decade of June, the maximum number of aphids - in the second decade. Over the years of observations, outbreaks of mass reproduction were in 1999, 2002, and 2021. The analysis is carried out of the dependence of the number of aphids Rh. padi on the weather conditions of the region. The correlation between the number of aphids on wheat plants and the average monthly April air temperatures was low (r= 0.31), it was higher between the number of insects and the June average monthly air temperatures (r=0.57). At the same time, the average monthly air temperature in April and June 1999 and 2002 were higher than the average long-term indicators. This indicator turned out to be the most effective between the sum of effective temperatures for the spring-summer period (April May, June) and the number of aphids (r= 0.77). The correlation coefficient between the amount of precipitation during this period and, accordingly, the number of aphids turned out to be negative (– 0.6). It is assumed that the degree of pest population of plants in the summer period depends on the number of eggs laid by oviparous females in the previous autumn. In our studies, the correlation coefficient between these indicators was 0.52. One of the most important entomophages of cereal aphids is the beetle Coccinella septempunctata L. Over the years of observations, the number of predators varied from 0.2 to 5 individuals per 1 model site. During the years of mass reproduction of aphids in 2002 and 2021, the number of coccinellids per model site was low and equal to 0.2-0.5. The large grass aphid Sitobion avenae F. appears in the fields of the region in early July. The largest number of species was recorded in 2016, 2020,2022. In the experiments of 2022, the insect preferred spring wheat and oats, compared with barley.

Growth regulators efficiency in onion planting material preparataion

Winter onion culture compares favorably with spring production with early harvest dates. In the conditions of the Krasnodar Territory, the first products arrive at the end of May-the first decade of June. However, obtaining a guaranteed harvest largely depends on the plants winter hardiness, which is determined not only by the prevailing conditions of overwintering, but also by the elements of growing technology, which include pre-planting preparation of seed onion. The article presents the results of studies on the influence of growth regulators used for soaking the sowing before planting for winter hardiness, the timing of the phenological phases onset, the dynamics of the leaf surface and bulbs growth, the size and structure of the crop. Seed onion was soaked before planting in solutions of three growth regulators (Radix, Radipharm, Rostok) for 12 hours, the control was a variant with planting material soaking in water. The seed onion of the first group (0.8-1.5 cm in diameter) was planted in early November, with 45 cm row spacing and 444.4 thousand pieces / ha planting density. It was found that Radix and Radipharm preparations significantly increased onion plants winter hardiness, the percentage of overwintered plants was 88.2-88.7% (80.3% under control), accelerated the ripening time of the crop (by 5-7 days), contributed to the activation of the growth processes of the aboveground apparatus. The pre-planting preparation of the seed onion did not affect the shooting processes intensity, the percentage of shot plants in the experiment was 7.5-7.9. The highest total yield of onion (39.2 t/ha) and the yield of standard bulbs (36.8 t/ha) with an average bulb weight of 102.2 g was obtained with the use of Radix. The increase in the yield in this variant and the earlier products’ entering the market contributed to net income increase compared to the control by 79.9 thousand rubles. The use of growth regulators for seed soaking had no effect on the products’ standard, it varied between 93.5-93.9%..

Calendar of flowering of woody plants in the Polar Alpine Botanical Garden-Institute named after N. A. Avrorin

The information about the timing and duration of flowering of woody plants makes it possible to plan the landscaping so that the plantings are the most decorative. Trees and shrubs are the most decorative during their blooming. The article presents key data on the flowering of woody plants in the Polar Alpine Botanical Garden-Institute (PABGI). The objects of the study were trees and shrubs in the PABGI collection fund. The material of the work was the data of phenological observations for the period from 2001 to 2020. We studied the beginning and duration of the growing season, the duration of the prefloral period, the timing, duration and abundance of the flowering. Trees and shrubs in the PABGI collection are characterized by an early beginning and a short duration of the growing season, a short and medium duration of the prefloral period. Early flowering in the second half of May is typical for wind-pollinated and flowering before leaf-out plants. The mass flowering of trees and shrubs is observed in the second decade of June and the first decade of July. Woody plants with a long prefloral period and long-blooming plants flower in August and September. Most trees and shrubs bloom within 6-10 or 11-15 days. The abundance of flowering is rated from moderate to excellent.

Assessment of the population status of the relict species Lomelosia austroaltaica (Bobrov) Sojak in the flora of the Kazakstan Altai

The article discusses the population parameters of a rare relict species Lomelosia austroaltaica in the territory of the Kalba Upland in the Kazakhstan Altai. It has been established that the population is located in the Eastern Kalba on the Medvedka Mountain (Koktau Mountains) as part of the feather grass-lomelosia phytocenosis. The total area occupied by phytocenosis with the participation of Lomelosia austroaltaica, is 2.5 hectares. Vegetation cover is poorly formed, represented by 30 species of flowering plants. The structure and appearance of the phytocenosis are determined by the dominants Stipa capillata- cop2, S. pennata - cop1. In ecological terms, the species composition of the higher vascular plants of the surveyed phytocenosis is formed by xeropetrophytes - 20 species (66.7 %), xeromesophytes - 7 species (23.3 %), mesophytes - 3 species (10 %). The total projective cover is 44.4 %, the proportion of Lomelosia austroaltaica in the phytobiota is 22.2 %, i. e. according to its coenotic features, the species is an assectator. Individuals are scattered and unevenly distributed over the area, their height ranges from 28 to 48 cm (33.6 ± 7.4.6), forming loose sods 47.9 ± 5.2 cm in diameter from 46.3 ± 7.2 cm vegetative and 51.3 ± 10.5 cm generative shoots. A direct dependence of seed productivity on the number of formed heads on a generative shoot was revealed. Mass flowering of individuals was recorded in the second decade of June, the period of seed ripening is late August - early September. The population is normal, incomplete, the age spectrum is left-sided. The ratio of young and adult fractions (pl + j + im) : (v + g) = 11.8 : 7.8 indicates a stable state of the population at the present stage. Mainly seeds maintain the number of individuals. The species needs state protection.

Features of seasonal development of black currant (<i> Ribes nigrum</i> L.) in the Arctic zone of the Russian Federation

Black currant is the most valuable berry crop of the Murmansk Province in terms of both biological properties and adaptive qualities necessary for growing in difficult agroclimatic conditions of the North. Every year, a search is carried out for varieties and forms with the best indicators of winter hardiness, yield, disease resistance and environmental friendliness, in order to identify accessions with the most valuable biological and economic traits. The objects of the present study were 24 cultivars of black currant of different ecological and geographical origin obtained in 2015 from the collection of the N. I. Vavilov All-Russian Research Institute of Plant Genetic Resources (VIR). Studies of the black currant collection were carried out in 2017-2021 at the Polar Experiment Station, a branch of VIR. The care of plants was provided according to the agricultural practices developed for growing berry crops in the Polar Region. The results of five-year phenological observations and assessment of winter hardiness in the studied cultivars showed that the onset of vegetation in all accessions occurred annually in the second decade of May, the onset of flowering in the second decade of June, the onset of maturation in the third decade of July, and the growth of shoots ended in the first decade of September. The studied cultivars were combined into groups according to winter hardiness (highly winter-hardy and winter-hardy), as well as the onset of phenophases (early, medium, late), and of ripening dates (early, mid, and late-ripening). Early vegetation was noted in cultivars ‘Pigmei’, ‘Izyumnaya’, ‘Rita’, ‘Volshebnica’, ‘Vasilisa’, ‘Almiai’, ‘Kriviai’, ‘Mila’, ‘Poklon Borisovoi’. Early ripening of the crop was observed in the cultivars ‘Severnoe Siyanie’ (C), ‘Mila’, ‘Izyumnaya’, ‘Rita’, ‘Kriviai’. The late maturing cultivars are ‘Slavyanka’, ‘Kipiana’, ‘Gratsiya’, ‘Chudnoe Mgnovenie’. The most numerous group is that of mid-ripening cultivars (64 %), followed by the group of early maturing (20 %), and late maturing ones (16 %). All the studied cultivars showed high adaptability to the conditions of the Murmansk Province. They had time enough to form the yield, complete the fruiting and growth of shoots before the onset of frosts. Due to the results of five years of research, they can be recommended for cultivation in the Arctic zone of the Russian Federation.

Corn in postcut crops

In agrotechnologies postcut crops of intermediate cultures are placed after harvesting annual grasses for green mass, and stubble crops after harvesting early grain crops. Annual herbs at the April sowing dates reach mowing maturity and are harvested for green mass in the third decade of June – the first decade of July. However, after harvesting the main crop of the crop rotation, there are still about 70–90 days left until the end of the growing season, which is quite enough to obtain a full-fledged harvest in the hay crops, and thereby increase the index of arable land use [1; 6]. In this regard in 2020–2022 in the foothill zone of the Kabardino-Balkarian Republic (the Baksansky district), the scientific research was carried out on the irrigated Ciscaucasian chernozems (according to B.A. Dospekhov “Methodology of field experience”) in order to study the elements of improving the technology of growing corn in hay crops, providing a reduction in energy costs and optimization of the main parameters of soil fertility. Recently, agricultural production has been operating in the conditions of a resource deficit and an increasingly complex structure of economic relations and an ever-increasing problem of soil and water conservation. The dominance of economic mechanisms fundamentally changes many generally accepted ideas and approaches in the field of agricultural land use. The overall objective is to maximize crop production per unit of input. As a result of the research, it has been found that the cultivation of corn for grain by cutting, after winter rapeseed by chisel processing to a depth of 28–30 cm and the application of fertilizers at a dose of N120P90, contributes to the stabilization of the agrophysical properties of the soil and the optimization of the energy balance

Influence of irrigation on the Sunn pest Eurygaster integriceps Put. (Insecta: Heteroptera) in the Central Forest-Steppe of Ukraine

The aim of the research is to establish the influence of watering on the phenological and biological features of winter wheat pests development, in particular Sunn pests. Trials were conducted on winter wheat crops under sprinkler irrigation in 2015-2020 in conditions of the Central Forest-Steppe of Ukraine. The size of the experimental plots in the field experiments was 50 m2 (10.4x4.8 m) at the 4 times replication. The allocation of plots was randomized. The average numbers of Sunn pest nymphs in 2015-2020 were 0.7-2.7 exemplars/m² on non-irrigated winter wheat crops and 0.8-3.8 exemplars/m² on irrigated. The share of the factor “presence of irrigation” that impacts on the number of Sunn pests reaches 80.2%. The sums of degree-days necessary for the beginning of different development stages of this phytophagous were calculated. The stage of the revival of Sunn pest nymphs began in mid-May – the first decade of June, which coincided with the phases of development of winter wheat: the end of flowering – soft dough ripening of the grain. The sum of degree-days required for the beginning of this stage was 177.8-233.8°C without irrigation, while in sprinkler irrigation conditions – 275.5-349.1°C. For the beginning of the transformation of the fifth instar nymphs into adults, the required sum of degree-days was 410.5-481.5°C on the non-irrigated crops and 545.7-630.4°C – under conditions of irrigation. Clarifying the sum of degree-days required for different stages of Sunn pest development will allow for predicting the terms of protective measures against this pest in the field conditions under irrigation.