Economic Threshold Of Harmfulness Research Articles

Effectiveness of sod and humus soil maintenance and biologized protection in intensive apple orchards (Malus domestica Borkh.) in the south of Russia

Application of intensive technologies in horticulture with a high mechanical and chemical load on soils and fruit plants leads to deterioration of soil properties, environmental pollution, and development of resistance among pathogens and phytophages. In this study, we aim to developing a biologized technology for apple tree cultivation using a sod and humus system of inter-row maintenance and biopreparations based on active strains of microorganisms, entomoacariphages, and pheromones. The research was conducted in 2019-2023 in intensive apple orchards of the central plain-steppe region of Crimea by the methods conventionally used in soil science, agrochemistry, horticulture, and plant protection. The use of a mixture of cereal-legume grasses in combination with microbiological fertilizers based on nitrogen-fixing microorganisms was found to increase apple yields by 11–12 t/ha, or 64 % compared to the control, by increasing the number of fruits and the average weight of one fruit. A positive balance of nutrition elements in soil with an intensity of 135-270 % was established. The efficiency of controlling the number of phytophages and pathogen harmfulness through the integrated use of biological and biotechnical methods was shown. Thus, the “attract-and-kill” method for Cydia pomonella L. pheromones demonstrated a 98 % efficiency along with a reduction in pesticide load to 7.7 kg/ha season by the preparation. Release of phitoseiid mites for control of tetranychus mites by the method of seasonal colonization provides for a reduction and retention of phytophagous population at the economic threshold of harmfulness during the entire vegetation period. The use of fungicides based on pathogenic bacteria of the Bacillus genus and antagonist fungi of the Trichoderma genus against scab is eff ective only in the years unfavorable for the development of the disease. The results obtained form the basis for a biologized resource-saving technology for exploitation of intensive apple orchards. This technology contributes to increased soil fertility, reduced chemical and pesticide load, and increased productivity of horticultural agrocenosis under the conditions of the Crimea and southern Russia.

ПРОГНОЗИРОВАНИЕ РАЗВИТИЯ ВОСТОЧНОЙ ПЛОДОЖОРКИ (GRAPHOLITA MOLESTA) С УЧЁТОМ ПОГОДНЫХ ФАКТОРОВ ДЛЯ РАЗРАБОТКИ СИСТЕМЫ ЗАЩИТЫ РАСТЕНИЙ МНОГОЛЕТНИХ НАСАЖДЕНИЙ

Modern agriculture is impossible without the use of plant protection products against pests and diseases, which, with their free development, significantly reduce the productivity of plantings and the marketability of the harvested crop. Research conducted in this direction abroad is aimed at using predictive mathematical models that link environmental factors that are significant for the pest and its development. At the same time, the system of intellectualization of such a forecast is increasingly being used with the use of artificial intelligence methods that independently form models based on constantly accumulating information databases. The aim of the study was to evaluate the effectiveness of an automated program for forecasting the development of the oriental fruit moth, developed on the basis of the temperature factor of the environment for the subsequent selection of an optimal adaptive plant protection system for perennial crops. To compare the results of the automated calculation of the development of the eastern fruit moth with objective data in the field, we carried out observations of the calendar dates of the butterfly flights and overcoming the economic threshold of harmfulness (ETH) on pheromone traps placed in peach plantations, on which chemical treatments with insecticides were not carried out in the period from 2019 to 2022. In the course of the research, a useful computer program was developed to determine the calendar dates of the development of the oriental fruit moth based on air temperature data using flexible logical algorithms. It is established that the variability of the terms of individual development of the pest provides an increase in the phase periods with each successive generation. The use of a computer program will allow us to develop a system for protecting trees from pests, as well as to adjust the timing of measures depending on objectively changing indicators of the conditions of the year.

Application of microcosms models for ecologically based selection of biofuel crops

One of the possible ways to solve the problem of shortage and rise in price of energy resources can be the development of the biofuel industry in Ukraine, the basis of which is the scientifically reasoned selection of plants (resistant to regional pollutants), taking into account the specifics of the regions. The article summarizes scientific data on the peculiarities of germination of some energy crops, considers the possibility of using microcosms for the reasoned selection of biofuel crops. The study was carried out in microcosmic models, seed germination and biometric parameters of seedlings Brassica napus L. and Zea mays L. were studied. Based on the application of the method of microcosmic models, the resistance of B. napus to lead acetate and sensitivity to the fungicide «Raxil ultra» were proven. To protect rapeseed from pests, systemic preparations with the active ingredients dimethoate, gamma-cyhalothrin, alphacypermethrin, thiamethoxam, fludioxanil, metalaxyl, imidocloprid, etc., are used. The insecticide is used for seed treatment before sowing (in combination with a fungicide), as well as for the treatment of crops when the economic threshold of harmfulness is reached. It was found that pre-sowing treatment of rapeseed should be carried out with lower concentrations of fungicide compared to Z. mays seeds. It was found that the Galitsky variety is characterized by the highest laboratory germination of seeds and the best morpho-physiological parameters of seedlings. It was found that the fungicide «Raksil ultra» in high concentration inhibits seed germination (at the late stages of germination), stem growth, cheese and dry biomass of corn seedlings, at a low concentration an increase in the dry weight of the aerial part was detected. Laboratory germination of rapeseed was inhibited at all stages of germination. None of the studied concentrations of the fungicide affect the raw and dry biomass of rapeseed seedlings, all the studied concentrations of the fungicide inhibit the root growth of rapeseed seedlings, and the largest inhibit the growth of the stem.

Species composition and features of weed control on irrigated lands in the system of forest strips

Under irrigation conditions, weeds reduce agricultural production. On irrigated lands in the conditions of the Volga region in the system of forest strips, weeds grow faster. The measures applied in the fight against weeds, depending on the species composition, are primarily an obstacle to their penetration into the fields and measures that are used in the fight against weeds in the irrigated field. In agricultural production, when irrigation is carried out in the system of forest strips, weed control must be carried out taking into account the species composition of weeds that determine the type of contamination and the economic threshold of harmfulness. Agrotechnical weed control measures have the maximum effect in the weed control system, primarily in combination with chemical protection of crops from weeds.

Rhizoctonia potato disease in production conditions in the forest-steppe of Western Siberia

The authors carried out a scientific study from 1990 to 2022 on 20 varieties of potatoes to study the pathogenesis of Rhizoctonia in crop production conditions and substantiate the methods of the system of protection against the disease. The fungus R. Solani persists annually in the soil and on seed tubers in the form of mycelium and sclerotia. It was found that more than 60% of the grounds of potato agroecosystems have the content of the causative agent of Rhizoctonia is many times higher than the established ETH (Economic threshold of harmfulness). Furthermore, monitoring of the phytosanitary state of potato seed material showed that, on average, about 60% of the tubers are inhabited by the causative agent of Rhizoctonia, including about 30% of the sclerotial form, which is six times higher than the phytosanitary regulations. Thus, in the region’s conditions, a double mechanism of phytopathogen transmission is provided annually. The causative agent of Rhizoctonia infects potato sprouts, subsequently causing their complete death (on average 12%) and shootouts, reducing the density of productive plants in crop plantings. At subsequent stages of growth and development of potatoes, significant expansion of the disease on the stems was noted (on average 31.4%), and stolons were damaged and died (9.3 and 5.5%, respectively), which disrupted the processes of stolon and tuberization. In the region’s conditions, Rhizoctonia occurs in the form of epiphytotic with a prevalence of 88% or more. Therefore, the potato protection strategy against Rhizoctonia should be based on methods that reduce the initial population density of the R. Solani fungus in the soils of agroecosystems and on seed tubers. Essential elements of potato cultivation technology are cropping rotation with a saturation of no more than 30% (biological efficiency - 43.2–79.5%); phytosanitary precursor, including green manure pairs (biological efficiency - 49.0–75.9%); mandatory etching with chemical preparations (biological efficiency - 54.9–98.8%) or natural origin. Using entomopathogenic fungi Metarhizium robertsii and Baeuveria bassiana can be a promising direction in reducing Rhizoctonia. Dressing seed tubers with conidia of entomopathogenic fungi suppressed the development of the disease in potato plantings by 1.8–3.7%, providing an increase in yield by 12.1–19.2%. The study of the influence of Metarhizium robertsii and Baeuveria bassiana on the pathogenesis of Rhizoctonia will be continued.

Parasitization of Bipolaris sorokiniana Sacc. Shoem. in the organ system of spring wheat varieties in the northern forest-steppe of Priobye region

The work aimed was to identify the effect of varieties on the parasitic activity of Bipolaris sorokiniana Sacc. Shoem. in the system of underground and aboveground organs of spring wheat. The research was carried out in 2020-2021 in the northern forest-steppe of Priobye region. The tasks of the study were to investigate the development of root rot and the etiology of the disease on the underground organs of a number of spring wheat varieties of different geographical origin; determine the role of varieties in the manifestation of dark brown leaf spot and black germ of spring wheat grain; establish the presence or absence of relationships between forms of helminthosporium; identify the effect of varieties on the intensity of reproduction B. Sorokiniana on root leaves and the number of conidia of the phytopathogen in the rhizosphere soil The authors used a collection of 15 varieties of spring wheat. The study did not identify any varieties whose underground organs showed resistance to fusarium-helminthosporium rot. Root rot development averaged over the organs to reach 3.8 units of Economic Threshold of Harmfulness (ETH) in 2020, and in 2021 - 4.4 units of ETH. The effect of the “variety” factor on the incidence of root rot in spring wheat was 31.8% and the “year” factor 30.3%. The authors presented the etiology of root rot of spring wheat cultivars by Bipolaris sorokiniana Sacc. Shoem. and fungi of the genus Fusarium Link. The ratio of phytopathogenes on underground organs was determined by conditions of the year and phytosanitary state of soil; the ratio varied from 1:1 to 11:1 with predominance of fungi of genus Fusarium. The prevalence of brown spot disease reached 1.9 units to 5 units ETH in the lactic maturity phase of the cultivars. The correlation coefficient between the development of root rot and the prevalence of dark brown spot was 0.526±251 and was statistically reliable. Variety differences in the prevalence of grain black spot reached 11.4 times, 3 varieties (Sibirskaya 17, Novosibirskaya 15, Ruslada) were affected at the threshold level; 4 varieties were affected to a moderate degree; 7 varieties were severely affected. Коэффициент корреляции распространенности темно-бурой пятнистости и черноты зародыша составил 0,521±232 и был статистически достоверным на 1%-м уровне значимости. The authors used Ward’s hierarchical clustering method to divide the plants into two groups according to the sporulation dynamics of B. sorokiniana on the root leaves of spring wheat. The first group of spring wheat was with a uniform rate. The second group were varieties of wheat with an exponential jump in sporulation intensity. The varieties Jin Chun 2 (China) and K-65834 (Tajikistan) were the most active sources of B. sorokiniana reproduction in both study years. The size of the soil population of the phytopathogen reflected the intensity

ВЛИЯНИЕ ФАКТОРОВ ВНЕШНЕЙ СРЕДЫ НА УСТОЙЧИВОСТЬ К БОЛЕЗНЯМ И УРОЖАЙНОСТЬ ГОРОХА

To increase the efficiency and safety of phytosanitary measures, it is necessary to combine all available methods and means aimed at long-term suppression of the number of pests below economic threshold of harmfulness. In this regard, the article provides data on the influence of external environmental factors (weather conditions, preparations for pre-sowing seed treatment) on disease susceptibility and yield of peas. The hydrothermal conditions corresponded to climatic conditions of the Trans-Urals during the period of the experiments and were favorable for cultivation of agricultural crops. It was established that the most common and harmful diseases of peas are fusarium (in the forms of root rot and wilting) and ascochitis. Pre-sowing seed treatment with fungicides was effective not only against root rot and wilting of peas, the development of the disease decreased by 1.2-1.6 times, but also against a group of leaf-stem diseases, susceptibility to ascochitosis decreased by 1.4-1.7 times. The influence strength of pre-sowing seed treatment on susceptibility of peas to Fusarium was 9.5-74.6 %, and weather conditions - 4.0-76.9 %. The development of leaf-stem infections was largely influenced by weather conditions of the growing season, the share of this factor was 13.7-88.7 %. Treatment of pea seeds with all the studied preparations provided a significant increase of yield by 9.7 ... 23.4 %. The influence of "Weather conditions of the year" factor in yield formation of peas was 72.8 ... 76.1 %, while the share of "Preparations" factor influence did not exceed 15.9 ... 18.3 %.

The impact of mineral nutrition on winter barley yields while using mustard as a precursor crop

The impact of mineral nutrition on winter barley yields while using mustard as a precursor crop

Biotic Factors in the Phytosanitary Technology of Green Pea Cultivation in the Trans-Urals

This article presents the results of studying the phytosanitary situation in the cultivation of 10 varieties of green pea in the Trans-Urals. We noted that the economic threshold of harmfulness by the soilborne and leaf-and-stem disease agents was crossed in the majority of the varieties. All varieties of the peas were affected by root rot above the economic threshold of damage (15%). In 2018, the level of root rot development was 55.5% on average in the varieties, or an excess of EPR by 3.7 times; and in 2019, the development of rot was 44.6% or an excess of EPR by 3 times. High rates of Fusarium blight were evident in the Zauralskiy 4, Kulon, Krepysh, and Samarius varieties, and bacterial blight in the Krepysh and Tomas varieties. Rust development varied on average over the two years from 10.5% to 16.5%, and 12% of the standard cultivar Aksayskiy Usatii 55 was affected. 11% of Samarius 13% of Agrointel and 11.5% of Zauralskiy 3 were affected. For all varieties, the development of powdery mildew was below the economic threshold of harmfulness (EPV = 15%). A higher percentage of disease development was noted in the Zauralsky 4 variety (11.0%) and in the Yamalsky 305 variety (13.5%). The productivity of the seeds treated with chemical fungicide increased 1.2-1.9 times as compared to the reference sample. The productivity growth of the seeds treated with biofungicides amounted to 1.09-1.11 times the reference. The authors recommend a pre-sowing treatment of pea seeds with preparations of symbiotrophic nitrogen fixers (such as nitragin, rhizotorfin), combined with their treatment with microelements: ammonium molybdate with 50% content of the active ingredient (250 g / t of seeds) and boric acid (250-300 g / t of seeds). Keywords: green pea, varieties, diseases, fungicide, yield.This article presents the results of studying the phytosanitary situation in the cultivation of 10 varieties of green pea in the Trans-Urals. We noted that the economic threshold of harmfulness by the soilborne and leaf-and-stem disease agents was crossed in the majority of the varieties. All varieties of the peas were affected by root rot above the economic threshold of damage (15%). In 2018, the level of root rot development was 55.5% on average in the varieties, or an excess of EPR by 3.7 times; and in 2019, the development of rot was 44.6% or an excess of EPR by 3 times. High rates of Fusarium blight were evident in the Zauralskiy 4, Kulon, Krepysh, and Samarius varieties, and bacterial blight in the Krepysh and Tomas varieties. Rust development varied on average over the two years from 10.5% to 16.5%, and 12% of the standard cultivar Aksayskiy Usatii 55 was affected. 11% of Samarius 13% of Agrointel and 11.5% of Zauralskiy 3 were affected. For all varieties, the development of powdery mildew was below the economic threshold of harmfulness (EPV = 15%). A higher percentage of disease development was noted in the Zauralsky 4 variety (11.0%) and in the Yamalsky 305 variety (13.5%). The productivity of the seeds treated with chemical fungicide increased 1.2-1.9 times as compared to the reference sample. The productivity growth of the seeds treated with biofungicides amounted to 1.09-1.11 times the reference. The authors recommend a pre-sowing treatment of pea seeds with preparations of symbiotrophic nitrogen fixers (such as nitragin, rhizotorfin), combined with their treatment with microelements: ammonium molybdate with 50% content of the active ingredient (250 g / t of seeds) and boric acid (250-300 g / t of seeds).
 Keywords: green pea, varieties, diseases, fungicide, yield

Efficiency of cultivation technologies for spring wheat with different levels of intensity on chernozem soils of Kursk Region

The paper presents the results of research on the efficiency of technologies for cultivating spring wheat at various levels of intensity (extensive, intensive, resource-saving) under the conditions of chernozem soils of Kursk Region. It was found that higher reserves of available moisture and nitrate nitrogen in the arable layer of the soil before sowing spring wheat were provided by technologies with moldboard plowing. Replacing plowing with subsurface methods of tillage led to a decrease in the available moisture and nitrate nitrogen reserves in the soil for all fertilizer systems. The lowest weediness of spring wheat was observed when it was cultivated using technologies with moldboard plowing 52.3-58.3 PCs/m2, depending on the fertilizer system. The replacement of plowing with subsurface and surface tillage increased the weediness of crops to 61.7 and 73.7 PCs / m2, respectively. Application of mineral fertilizers had almost no significant effect on the number of weeds in spring wheat. The highest yield of spring wheat in all the years of studies (4,27 t/ha) was obtained in the intensive cultivation technology involving plowing at 20-22 cm, fertilization at a rate of N60Р60К60, treatment of crops with pesticides based on economic threshold of harmfulness. Yield of spring wheat, cultivated by resource-saving technologies with organic-mineral system of fertilization 0.86-4.25 t/ha depending on the methods of primary tillage. Moldboard plowing of the soil against the background of the organic-mineral fertilizer system increased the yield of spring wheat by 0.18 t/ha in comparison with subsurface tillage and by 0.39 t/ha in comparison with surface tillage. However, due to higher production costs, the best economic indicators were obtained when spring wheat was cultivated using resourcesaving technologies with an organic-mineral fertilizer system and non-moldboard methods of primary tillage.

Population and harmfulness of phytophages in peach orchards in the conditions of the Southern Steppe of Ukraine

Goal. To determine the number and harmfulness of the main phytophages on peach cultivars of different ripening terms in order to plan measures to protect the crop from pest damage.
 Methods. Laboratory-field. The research was carried out in peach orchards of the Scientific and Production Site «Naukova» of Melitopol Fruit Growing Research Station named after M.F. Sydorenka of Institute of Horticulture of NAAS according to generally accepted methods. Monitoring of the number of phytophages was performed on peach cultivars of different ripening terms: Iiun`s`kyi rannii, Melіtopol’s’kyi iasnyi, Charivnyk, Zlatodar, Vireneia, Redhaven, Spokusa, Zolotystii, Mriia and Yuvileinyi Sydorenka during bud swelling, inflorescence opening (pink tip), flowering, growth and maturations of the fruits.
 Results. Entomoacarocenosis of peach plantations has 15 species of insects pests and 2 species of mites. During the flowering period, the main harmful species was Epicometis hirta Poda., the number of imagoes in different cultivars was 0.3—5.8 specimens/100 flowers. Population intensity of peach trees with green peach aphids (Myzodes persicae Sulz.) for certain cultivars reached the level of 1.9 points, mealy plum aphid (Hyalopterus pruni Geoffr.) — did not exceed 0.8 points. Density of mites, Thrips fuscipennis Haliche and Typhlocyba rosae L. varied in the range of 0.4—2.5; 0.8—2.4; 0.5—1.6 specimen/leaf, respectively. The main fruit-damaging pests in peach orchards were oriental fruit moth (Grapholitha molesta Busck.) and peach twig borer (Anarsia lineatella Zell.). The degree of fruit damage by Lepidoptera pest oriental fruit moth on early-ripening peach cultivars was 3.0—4.0%, increased on medium- and late-ripening cultivars to 6.8% and 11.7%, respectively. The level of fruit damage by peach twig borer compared to the eastern fruit moth was 2.8—10.7 times lower, depending on the cultivar.
 Conclusions. In the conditions of the South of Ukraine, 15 insect pests and 2 species of mites were recorded in peach orchards. During the growing season, the number of most species of phytophagous, including weevils, leafroller moths, mites, thrips, Typhlocyba rosae on different peach cultivars did not exceed the economic threshold of harmfulness. During the flowering period, Epicometis hirta was the threat to peach orchards. In the summer of 2019, the harmful effects of sucking phytophages, in particular aphids, led to delayed growth and development of shoots, deformation of leaves. The main species of pests that reduced the yield and fruit quality were oriental fruit moth and peach twig borer.

Entomocomplex of peach plantations in the vegetation period

Goal. Study of the entomocomplex of peach plantations in order to plan appropriate measures to limit their harmfulness.
 Methods. Laboratory field. The population of peach trees by pests was determined according to generally accepted methods in the Research Garden of the Dmytro Motorny Tavriya State Agrotechnological University. Census counts were conducted in peach plantations of the Crimean Fireworks, Jubilee Sidorenko, Redhaven, Skazka, Vireney and Ambassador of Peace varieties.
 Results. It was found that in the agrocenosis of peach plantations during 2018—2019, three permanent species of pests were registered: California thymus (Quadraspidiotus perniciosus Comst.), Turkestan mite (Tetranychus turkestani Ud. Net Nik.) And eastern fruit eater (Grapholitha molesta Busck). The adult age of the last phytophagous began with the beginning of flowering peach trees and lasted until September. The number of butterflies in pheromone traps varied during the growing season from 24.7 to 48.5 specimens / trap, ie significantly exceeded the economic threshold of harmfulness. It should be noted that despite the very high age of the pest in the experiment, damage to peach shoots in all varieties (except Crimean fireworks and the Ambassador of Peace) was below the economic threshold of harmfulness (0.1—1.0%). The population of peach leaves by Turkestan mite on different varieties was 0.1—1.5 specimens / leaf. Studies on the peculiarities of the development of the Californian thyroid have shown that the beginning of the flight of males of the first generation was recorded in pheromone traps in the second decade of May. In 2019, this phase of development is marked a week later. The revival of traveling larvae also occurred at different times, with slight fluctuations. The number of California thyme on peach varieties ranged from 0.8 to 17.2 specimens / shield.
 Conclusions. On peach cultivars the California thyme (up to 17.2 specimens/shield), oriental fruit fly (from 0.3 to 2.5 specimens/shoot) and Turkestan spider mite (up to 23.8 specimens / leaf) were noted, depending on The high potential of California thyme reproduction in peach plantations on the Crimean Fireworks, Virenea and Ambassador of Peace varieties has been recorded.

Pests in cherry plantations in the conditions of the Southern Steppe of Ukraine

Goal. To study the biological resistance of cherry varieties of different maturity against pest and to determine their number.
 Methods. Laboratory field. The population of cherry trees by pests was determined by conventional methods in the Research Garden of the NNVC Tavriya State Agrotechnological University. The final pest population of trees was assessed on a five-point scale.
 Results. The results of studying the phytosanitary condition of cherry plantations in the conditions of the Southern Steppe of Ukraine are given. It was found that in 2018, 8 species of pest predominated, and in 2019 — only 5. The permanent species of pest were cherry aphid, rose leafhopper, cherry fly and Turkestan mite. It should be noted that the population of the above pests in the years of research was at the level of 0—2 points. In 2018, single black weevils and geese were recorded in cherry plantations at the level of 1 point, and the following year these species were completely absent. During 2018, all varieties, except Dilema and Udivitelnaya were inhabited by mobile stages of red fruit mite from 0.6 to 3.0 specimens/leaf. In 2019, the population of hawthorn mites was observed above the economic threshold of harmfulness on the varieties Melitopol Black, Announcement and Talisman (3.3—7.3 specimens/leaf), which corresponds to 4—5 points. The number of California thyme in cherry plantations of almost all varieties was higher than the threshold value, the maximum was observed in the variety Melitopol black — 5.6—8.5 specimens/shield.
 Conclusions. Resistance of cherry varieties by groups of maturity to the presence of pests was not detected, all varieties to some extent were covered by harmful entomofauna. Ongoing monitoring studies in cherry plantations from the moment of bud burst to harvest can increase the effectiveness of protective measures by timely assessment of the population of each species of pest.

Technical efficiency of spring rapeseed protection scheme

The species composition of weeds and pests in the crops of spring rape of the variety Nadezhny 92 was determined, the technical effectiveness of the protection scheme of the Syngenta company was evaluated. The results of the study showed that the prevailing species were cereal weeds of 17.9 units / m2. Dicotyledonous weeds amounted to 13.6 units / m2. A decrease in the moisture supply of the vegetation period entailed an increase in weediness. The highest weediness was recorded in 2019, when the number of weeds was higher than in 2017 and in 2018 on 23.5 - 18.0 pcs / m2. Of the pests, cruciferous fleas, rapeseed beetle, rape sawfly, and caterpillars of cabbage were found in the crop. Spring rape protection scheme: presowing treatment with Cruiser Rapeseed, KS, Zellek Super, KE Galera Super, BP, Karate Zeon, MKS showed high technical efficiency. Technical efficiency against cereal weeds was 84.4%, against dicotyledons - 90.4%. On average, the protection effect on spring rape crops was 86.3%. The use of an insecticide allowed reducing the number of pests in crops below the economic threshold of harmfulness or completely destroying them.

Monitoring of winter rye diseases in Kirov region and possible trends of breeding for immunity

The analysis of the phytosanitary situation in production, selection and seed crops of winter rye in Kirov region for the period from 1999 to 2018 was carried out in order to adjust the tasks of breeding for resistance to the most harmful diseases. The affection of the sowings (spread of the disease), the development of the disease and the area of the affected crops relative to the number of the examined ones were evaluated. The trend in the development of the diseases was established on the basis of a regression analysis of long-term data of the branch of the FSBI Rosselkhozcentr in Kirov region. The annual (100 %) manifestation of snow mold and ergot has been established. Next according to the frequency of manifestation there are root rots and brown rust – 95 %, powdery mildew – 75 %, sclerotinia – 70 %, Fusarium head blight – 70 %, and stem rust – 50 %. A relatively low frequency of manifestation has been observed with septoriose and rhynchosporium – 35 and 30 %. However, taking into account the development of winter rye diseases which exceed the economic threshold of harmfulness (ETH), the studied pathocomplexes have different levels of danger. Thus, the development of brown rust above ETH was diagnosed 13 times within 19 years. The most severe disease development (20.0-52.0 %) was in 2001, 2005, 2009, and 2010; weak - in 2007 (0.8 %), 2017 (1.4 %), 2015 (2.4 %), and 2011 (5 %). The manifestation of powdery mildew above ETH was observed 6 times within 15 years, disease development was at the level of 13.0-53.0 %. The development of septoriose above ETH was diagnosed 6 times within 7 years with the development of disease from 13.5 to 63.0 %. Development of stem rust above ETH was diagnosed 5 times within 10 years with the status of the sign of 15.0-20.0 %. The cyclicity of spread of the most harmful diseases and trends of their change in agrocenoses of winter rye are shown. Thus, the most epitphytotically dangerous diseases include snow mold, brown rust, stem rust, powdery mildew and septoriose. Constant control is also required in relation to ergot and Fusarium head blight. These diseases should be an object for breeding-and-immunological studies.

Prognostication algorithms and predictability ranges of mass reproduction of harmful insects according to the method of nonliner dynamics

The authors have analysed the theoretical possibilities of prognostication the dynamics in the number and mass reproduction of some species of harmful insects. A theoretical synthesis of the information on the regularities of the population dynamics of the most common insect pests of agricultural plants from the point of view of the methodology of nonlinear dynamics and synergetics has been done. Based on the past and present an analysis of the many-year dynamics in the number of the insect populations has been carried out and an attempt to develop the algorithms for prognostication the seasonal and annual changes in the number of the insects has been made. To do this the authors recommend a scenario-based method of prognostication and making decisions in plant protection. Using the phytosanitary monitoring they determine the beginning of the regular mass reproduction (the appearance of an aggravated rate) and then, based on the phytosanitary prognosis, an aggravation of the situation that has developed or is being developing on the farm, in the district or in the region is made; after that on the base of the short-term prognosis (signaling) it is recommended to make the optimal decision to protect a particular crop taking into account the economic threshold of harmfulness. According to the authors this approach, based on the methodology of nonlinear dynamics (synergetic paradigm), makes it possible to determine in advance the breeding grounds of the aggravated rates and make the optimal decisions in plant protection. The predicted scenario will not be a prognostication of the future, but the elements of an evolutionary process inherent in nature.

Results of long-term use of pheromone traps to monitor harmful tortricid moths in Leningrad Region of Russia

Monitoring the population dynamics of harmful moths using synthetic sex attractants in Leningrad Region was carried out in the fruit experimental orchard of St. Petersburg Agrarian University (Pushkin) and small private orchards of Pushkin district. As a result of the analysis of many years temperature characteristics of vegetation seasons in the Leningrad Region and calculation of the sums of effective temperatures, it has been found that the codling moth had high numbers and developed in two full generations in 1999, 2002, 2006, 2013 and 2018. The complex of phytophagous leaf rollers as a whole can cause sometimes significant harm to both industrial orchards and homestead lands, because the economic threshold of harmfulness by yield losses is often achieved, when plants are damaged by more than one pest species, each of which causing only weak harm. As a general conclusion, the complex of orchard leaf rollers is a dynamic system. Their development and numbers ratio is influenced by weather conditions of a year and climate changes in general.

Prospects and technology of cultivation of organic vegetable production on open ground in southern Russia conditions

To receive a high-quality competitive and environmentally friendly product, you need a well-thought-out agricultural technology, high level of biosecurity and spatial isolation. To develop an effective technology for growing environmentally friendly new potatoes, in the soil and climatic conditions of the high-altitude zone of Kabardino-Balkaria, scientific work was carried out, taking into account the achievements of modern agriculture. In the conditions of the mountain zone, nature has created a clean phytosanitary zone, in which you can get high-quality, environmentally friendly products without increasing their cost. The production process in this case will exclude the control of diseases and pests that in this zone will not exceed the economic threshold of harmfulness. In potato seed production, the initial stage was the use of improved material for growing a regenerating plant from the meristem, propagated in sterile, laboratory conditions for further cloning. With such seed material that is initially free of pathogens, it is much easier to get organic products. According to various estimates, the cost of producing environmentally friendly products in agriculture is 2.5-3 times higher than the cost of traditional production, and as a result, the cost of products increases. The analysis of economic efficiency showed that the increase in net income depends on the received potato yield and the sale price of new potatoes.

Efficiency of the preparation based on Bacillus thuringiensis and nuclear polyhedrosis virus against diamond back moth (Plutella xylostella)

Studies have been conducted to assess the effectiveness of bioinsecticide preparation based on the sporocrystalline complex Bacillus thuringiensis and the nuclear polyedrosis virus. Before the preparation usage, a significant excess of the economic threshold of harmfulness for the investigated pest was noted on the experimental area of 1 ha. In the first survey of the site, Plutella xylostella caterpillar numbers on one plant varied within 5-6 caterpillars range when 62% of white cabbage plants were settled. After 3 treatments with an experimental preparation, the number of caterpillars decreased to 98 sp./100 plants and biological efficiency was 80.4%. Also, the effectiveness of the biopreparation in comparison with chemical insecticides was proved by single-factor dispersion analysis (Fobs.= 9.05; Fcrit.= 5.98).

Integrated pest management of flea beetles (Phyllotreta spp.) in spring oilseed rape (Brassica napus L.)

One of the most dangerous pests of rape is a complex of the undulating flea beetles that can do harm to the plants from the phase of sprouting and until the harvest ripening. According to our research, all six species of the undulating flea beetles are spread in the Eastern Forest–Steppe of Ukraine. The most numerous species are Phyllotreta atra F. (about 71%) and Phyllotreta nigripes F., the latter is less numerous (about 16%). The rest 4 species make up from 0.4 to 8.8% in the population structure. The damage of spring rape sprouts caused by the leaf beetles both against the background with the fertilizers (N30P30K30) and against the background without the fertilizers significantly affects a weight of 1000 seeds. Against the background without the fertilizers it is a little less and R²=0.875 while against the background with the fertilizers R²=0.9986. The yield capacity of spring rape both against the background with the fertilizers (N30P30K30) and against the background without the fertilizers depends on the degree of the sprouts damaged by the leaf–eating pests largely. It is a little higher against the background without the fertilizers and R²=0.9995 while against the background with the fertilizers R²=0.9911. The presowing toxicity of spring rapeseeds with the subsequent spraying of the crops in the phase of sprouting, namely the toxicity of two pairs of true leaves, provides a reduction in the density of the undulating flea beetles population 7.5–10.0 times below the level of the economic threshold of harmfulness. The best field germination of rape seeds both against the background without the fertilizers and against the background with the fertilizers is noted. The applied insecticide and fungicide seed treatment agents have a negative affect on the laboratory germination of spring rape seed material. The worst indices of germination were noted in the variants when applying Royal FLO, 48% of water and suspension concentrate in the dose 5.0 L/t and Royal FLO, 48% of water and suspension concentrate+Taboo, 50% of suspension concentrate in the dose of 5.0+6.0 L/t and on the 9th day these indices were 77.0% and 76.5% respectively.