Plant Protection Methods Research Articles

Фітосанітарний стан агроценозу пшениці озимої у Південному Степу України

It is established that winter wheat belongs to the oldest crops and is the main food product in many countries. In Ukraine, the sown area of winter wheat is 5–6 million hectares. More than half of winter wheat grain production falls on the steppe zone. Cereal crops are damaged by insects in all growing zones, especially in the steppe zone of Ukraine. This is due to both the significant diversity of harmful species and the fact that in this area they reproduce most quickly and intensively. In addition, the lack of spring and summer precipitation exacerbates the negative significance of damage. Feeding insects on cereals causes a wide variety of damage, both in nature and in consequences for plants and crops. It is determined that one of the urgent problems of winter wheat protection is the study of patterns of dynamics of the number of major pests in modern agrobiocenoses. According to many scientists, global warming has affected the structure of entomocomplexes, as it optimizes environmental factors for the activities of insects, leads to their reproduction and spread. Harmful entomocomplex of winter wheat covers more than 360 species of insects. They damage the plants of this strategically important crop during all periods of growth. However, the species structure, level of dominance, number and harmfulness of insects are constantly varying, largely due to changes in climatic conditions associated with global warming. The article analyzes the phytosanitary status of winter wheat agrocenoses in the Southern Steppe of Ukraine during 2017–2019. The aim of the study was to determine the species composition and population density of insects in the modern entomocomplex with different technologies of growing crops in short-rotation crop rotations of the Southern Steppe of Ukraine. The research was performed in the research field of the Odessa State Agricultural Research Station of the National Academy of Agrarian Sciences of Ukraine. Observations and records were carried out in all phases of plant development during route inspections of winter wheat fields and adjacent fallows and other stations according to generally accepted methods of entomology and plant protection: mowing with entomological net, shaking of individual plants, test sites and test plants. The species composition of the detected insects was determined in the laboratory. According to the results of studies of the species composition and population density of insects in modern entomocomplexes, it was found that the vast majority of identified species – 78% belong to phytophages, 17% – to entomophages, 5% – to neutral species. Changes in the entomological complex and population levels of the phytophagous complex of the agrocenosis of winter cereals have been revealed. 46 species belonging to 19 families from 8 orders of the insect class were found in the harmful entomofauna. Significant fluctuations of entomocomplex structures in short-rotation crop rotation in the conditions of the Southern Steppe of Ukraine have been established. In particular, with the use of typical zonal technologies for growing crops, which lead to the reproduction of specialized pests.

Toxicological and ecotoxocological characteristics of pesticides important for their sustainable use

Modern concept of reducing the risk of pesticide use is based on the concept of sustainable use of pesticides. The concept of sustainable use of pesticides presents the range of professional rules, acts, skills of the pesticides use with the aim to promote the plant protection with decreased usage of pesticides, providing, whenever it is possible, advantage to non-chemical methods of plant protection. The most important part of sustainable pesticide usage is integrated plant protection. Integrated plant protection implies the application and integration of all available methods of plant protection which prevent the development of population of the harmful organisms above the level of harmfulness, considering that the usage of means for plant protection is at the level which is economically and ecologically justified. Risks for the human health and the environment is decreased or at least reduced to the minimum by the concept of pesticide application according to the integrated plant protection. Pesticides have certain potential to cause damage effect if people and the other organisms are exposed at the certain conditions and amount. Modern toxicology is directed to determine the safe dose, meaning the dose without the harmful effect as well as finding out the way of safe pesticide use. Considering the modern toxicology, two important terms are hazard and risk. Hazard is the intrinsic characteristic of the chemicals to cause the harmful effect at the defined conditions of the exposition. Risk is probability of manifestation of the harmful effect at the certain conditions of the exposition. The harmful effects of pesticides on humans mostly depend on the pesticides’ own toxicity but on the human’s exposure as well. The exposure of people to pesticides can appear at the working place. Farmers can be exposed to pesticides during the work in the open field and protected space, while the significant exposure can appear with workers in the pesticide industry as well as with workers who deal with jobs of deratization and disinsection and with workers in pesticides wholesale and retail. Estimation of the exposure of the agricultural workers is complex. Professional users are mostly exposed but the exposure is episodic. The particular problem is estimation of the exposure of the field workers and their householders as well. Therefore, while estimating the people’s exposure to pesticides in theresidential buildings, the remains of the pesticides in water, food, dust and air in and around the house is considered. Increased amounts of the pesticides in the house dust are related to exposure which depends on the distance between houses and the pesticide-treated fields, exposure in the house due to the fact that one or two householder work in the agriculture and larger use of pesticides in the residential buildings for treating different insects in the house or yard. Pesticides, besides their negative effects on people’s health, can have harmful effect on the environment, meaning that they can contaminate surface and underground water, soil and air, and to have toxic effects onto non-target organisms. There is a large number of documented papers where is proved that use of pesticides has great consequences onto the population of autochthonous wild animals. Integrated plant protection and sustainable use of pesticides cannot be only a declarative determinant. A wide range of steps have to be undertaken to enable their use in practice. Future imposes huge professional challenges related to the use of pesticides. The need to fulfill the different, sometimes even opposite demands is often imposed. On one side it is demanded to provide pesticides efficiency in protection from the harmful organisms and on the other side sustainable use and decreasing the risk for people and environment. Development of the new pesticides with the new ways of action and improved safety profiles and application of the alternative systems of plant production which will be less dependent on the pesticides could reduce the exposure to pesticides and side effects on people. The use of appropriate and well maintained equipment for pesticide use, while taking all protection measures at all stages of pesticides handling, can reduce the exposure to pesticides. Implementing the concept of sustainable use of pesticides is difficult, but for now it is the only promising way to ensure the protection of people, the environment and the production of healthy food.

Сучасний стан застосування біологічних засобів захисту рослин в агроценозах України

Goal. To analyze the long-term data on the development and application of biological plant protection products in Ukraine. Methods. Micro­biological, biochemical, entomological, field, mathematical-statistical, and information-analytical. Results. It is established that in Ukraine for the last 20 years the areas of cultivated agricultural lands treated with biological means of plant protection against pests decreased from 8.5% (2000) to 3.6% (2019), and in 2006 the share of the areas treated with bioresources was the lowest (2.9%). Most biological drugs are used against mouse-like animals, gnawing and leaf-eating moths, stem butterfly and pest complex in vegetable and grain agrocnosis, and in orchards. Scientific developments on the biological method of plant protection are given. An ecologically safe system of protection of vegetable crops of open and closed soil is developed and tested. The search for highly effective strains of microorganisms for the creation and development of new biological preparations is carried out. Methods of step-by-step selection with the determination of productive monoisolates to obtain production strains of entomopathogens have been studied. The deep technology of low-tonnage production of the biological product Trikhodermin-R for the conditions of bio laboratories of Ukraine has been improved. Conclusions. It is established that the cultivated areas treated with biological plant protection products decreased every year and in 2019 amounted to 1.8 million hectares out of 49.8 million hectares of all cultivated areas. The Institute of plant protection of NAAS has developed an environmentally friendly system of protection of vegetable crops in open and closed soil against pests and created a collection of highly active and productive strains of entomopathogens, microorganisms-antagonists, predatory nematophage fungi — producers of biological drugs, plant protection products in Ukraine.

Combination of Chemical and Biological Methods for Effective Plant Protection

The application of combined biological and chemical techniques to control undesirable processes in plant cultivation is becoming ever more important to maintain sustainable and environmentally friendly agricultural systems. Entomopathogenic nematodes and bacteria can provide an effective and special technology in the field of plant protection.

The Impact of Biopreparations and Phytopathogenic Bacteria of the Pseudomonas Genus on L-Phenylalanine Ammonia-Lyase Activity in Soybean and Lupine Plants

It is known that plant protection against diseases is based mainly on the use of pesticides. These chemicals or their degradation products have a detrimental effect on the environment and human health. Due to this, the search for methods of plant protection that are safe for the environment is becoming increasingly popular. Induction of plant resistance to disease is one of the promising non-chemical ways of protection, in which plant enzymes play a key role. It was shown that in response to pathogen invasion, plants enhance protective properties by inducing the activity of a wide range of enzymes that slow the spread of infection, in particular: peroxidases, β-1,3-glucanases, chitinases, polyphenol oxidases and L-phenylalanine ammonia-lyase (PAL). The aim of the research was to study the change in PAL activity in soybean and lupine plants under conditions of artificial infection with some phytopathogenic bacteria of the Pseudomonas genus and under the action of Ecovital and EPAA-M biological preparations. Methods. PAL activity was determined spectrophotometrically. Changes of soybean (Glycine max) and lupine (Lupinus luteus L.) plants resistance to diseases caused by bacteria of the Pseudomonas genus were evaluated using phytopathological methods. Statistical processing of the research results was performed using MS Excel computer program with Student’s t-test and estimation of least significant difference (LSD). Results. It was found that under conditions of soybean and lupine plants infection with phytopathogenic bacteria of the Pseudomonas genus on the background of pre-sowing seed treatment with Ekovital and EPAA-M biological preparations, composition based on them and synthetic standard – salicylic acid a significant increase in FAL activity in the aboveground and the degree of infectious roots – reducing of plants with pathogens was observed. It has been established that the growth of PAL activity under the condition of infection with phytopathogenic bacteria of the Pseudomonas genus occurs after 2–6 h and lasts up to 7 days from the moment of phytopathogen invasion into the plant. The most increasing of PAL activity was after treatment of seeds with Ecovital and EPAA-M composition – by 38.1–73.3% (Lupinus luteus L.) and 60.4–110% (Glycine max) compared to the control. Treatment with the composition of biological products also helped to reduce the degree of plant damage. PAL activity increasing and reducing the area of soybean and lupine leaves affected surface can indicate the induction of protective reactions in plants. Conclusions. The use of the composition of EPAA-M with the microbial preparation Ecovital contribute to the increase of PAL activity and the formation of resistance to phytopathogenic bacteria of the genus Pseudomonas in Glycine max and Lupinus luteus L. plants.

Biological Methods of Plant Protection against Viruses: Problems and Prospects

Viral diseases cause significant crop losses and a deterioration in the quality of agricultural products. There are currently no direct methods with antiviral agents to protect plants from viruses circulating in agroecosystems. Control measures focus on the selection of varieties that are resistant to viral diseases, the improvement of varieties via the cultivation of apical meristems, and control of the number of insect vectors. The review describes modern approaches to plant protection against viruses via genome editing, regulation of the expression of the host plant and/or viral genes via RNA interference, and the formation of an artificial consortium of plants with rhizospheric and/or endophytic microorganisms that combine protective activity and immunomodulating potential.

Economic efficiency of biological methods use of plants protection

The economic efficiency of the application of biological methods of plant protection is investigated. The analysis of the state of agriculture and, in particular, crop production in the Turkestan region. The foreign experience of using biological methods of plant protection is studied and the ways of their application in Kazakhstan are determined. The classification of rural areas is made according to indicators characterizing social and economic development, including economic potential. The essence of plant protection methods is determined; calculations of the economic efficiency of the use of bioagents on the sown areas of cotton in the Maktaaral district of Turkestan region; the foreign experience of applying biological methods of plant protection was studied and the ways of its implementation in Kazakhstan were examined; calculation of the need for biological laboratories, the results of the study are generalized. The authors substantiated the effeciency of the application of biological methods of plant protection. In many agricultural formations of the Turkestan region, drip irrigation systems are used. As it is known, in this case, with higher air humidity in the region of the trunk and near the leaf surface, the effeciency of the use of biological products becomes higher, since in conditions of high humidity, bacteria and fungi, which are the basis of the active substance, are more productive and virulent.

Біометод — основа сталого розвитку вітчизняного землеробства

Goal. To study the dynamics of processes and the current state of application of biological plant protection products in Ukraine, the main trends in world markets for organic products and domestic production of biological products, to identify tasks for the implementation of bio methods in the context of organic farming in Ukraine. Methods. Analytical, economic and statistical, comparative analysis, graphical, cartographic. Results. On the background of significant growth in the production and use of biological plant protection products in the EU and the world, the use of safe methods of protection in Ukraine is declining. With the growth of the range of microbiological means of protection included in the «List of pesticides and agrochemicals in Ukraine», the production capacity for the production of biological products has sharply decreased. Thus, in 2019, there were 24 biofactories and bio laboratories in Ukraine, and their total number, including private-sector production, was over 45, while by 1990 there were 268 biofactories and bio laboratories in Ukraine. Conclusions. The use of environmentally friendly biological plant protection products in Ukraine for a long time is at a very low level and tends to further decrease. To intensify the transition to environmentally friendly methods of plant protection, the development of domestic production of biological plant protection products, as well as the process of greening agriculture, they propose strategic approaches to the formation and development of a common system of environmentally friendly methods of plant protection on the new technological and organizational basis.

Numerical Simulation on Deposition of Atomization Droplet of Air-assist Boom Spraying in Air Flow

Air-assist Boom Spraying is a crucial technique and spray method of plant protection which has a significant effect on improving the efficiency of pesticide application and reducing droplet drift. Spraying drift is the main reason for the low utilization rate of pesticides, at the same time, the interaction of natural wind and the air bag wind is the main cause of spray drift. But at present, the regularity of spray droplet deposition and motion trajectory under the common influence of natural wind and air bag wind is not yet clear. The kinematics characteristics of the droplets deposition of air-assist boom spraying in the plants is investigated with numerical simulation method. The Phase Doppler Particle Analyzer (PDPA) is used to validate the numerical simulation results and it indicates that the deposition process can be well reproduced. The results show that the bigger droplets (>150 μm) get more kinetic energy from the vertical airflow and locate in windward side. These droplets are not sensitive to the horizontal airflow and are easier to deposit within a short time. The droplets with smaller size (<150 μm) are minimally influenced by the vertical airflow and suspend in the upside of the flow field. The vertical airflow not only prevents the horizontal airflow drift the droplets, but also introduces a vortex region near the canopy of the plants, which rotates the plant canopy and increases the droplet deposition on backside of the leaves. This study improves the understanding of the droplets deposition under the multi-wind fields and provides the theoretical basis for the innovation of the air-assist boom spraying system.

CALIFORNIA SHIELD BEETLE IS A DANGEROUS QUARANTINE PEST OF AN ORCHARD IN THE SOUTH-EAST OF KAZAKHSTAN

The article presents data on the influence of damage to trees by the California shield on themeasurement of growth processes of Apple trees. On trees with a degree of damage of 4 points and covered withshields, cracks were formed, which eventually lead to the suppression of growth processes and the gradual death oftrees. Therefore, the California shield should be suppressed as much as possible in the first generation to preventdamage to the fruit.During the research, we used generally accepted methods of plant protection and quarantine. Pheromone trapsfor catching the California shield were hung during Apple blossom, along the periphery of the tree crowns at a heightof 2 m, in the middle rows of the array at the rate of 1 trap per 2 hectares of fruit-bearing garden. Surveys of fruitstands using pheromone traps were carried out only during the summer of males. The traps were checked every7-10 days, and the pheromone was changed 1 time in mid-summer.The results of observations showed that with the highest degree of infection of trees, which is 4 points, thegrowth of shoots is reduced compared to a healthy tree by 36.4%, respectively, the leaf surface area is reduced by38.8%. On trees with a degree of damage of 4 points and covered with shields, cracks were formed, which eventuallylead to the suppression of growth processes and the gradual death of trees.According to the data obtained, when trees were populated with 2 points, the percentage of affected apples was14.3%, when a tree was populated with 3 points, 42.5%, and 55.6% of the fruit was damaged with 4 points. Even ifthe pest infects 14% of apples, the products are perceived as not standard and not high-quality, so the Californiashield should be suppressed as much as possible in the first generation to prevent damage to the fruit.

Beetle Orientation Responses of Gastrophysa viridula and Gastrophysa polygoni (Coleoptera: Chrysomelidae) to a Blend of Synthetic Volatile Organic Compounds.

The invasive weed Rumex confertus Willd. (mossy sorrel) is eaten and severely defoliated by oligophagous Gastrophysa viridula Deg. (dock leaf beetle) and Gastrophysa polygoni L. (knotweed leaf beetle). The most popular methods of plant protection involve the application of chemicals, but such methods often require repeated chemical treatments. Aromatic plants may constitute an eco-friendly alternative strategy owing to their repellent properties. To date, single compounds have been tested rather than blends; however, there is a need to investigate mixtures of compounds, because insects are subjected to blends of odors derived from their surrounding environments. The aim of the current study was to investigate behavioral responses of the dock leaf beetle and knotweed leaf beetle to a blend of synthetic plant volatile organic compounds. Plants were treated with standard repellents (a blend of volatile organic compounds) at two different concentrations (10 ng min-1 and 1,000 ng min-1). For further experiments, four rates (1 ng min-1, 10 ng min-1, 100 ng min-1, and 1,000 ng min-1 in 50 µl) were evaluated using a 4-way olfactometer. Leaf beetles of both sexes were repelled by the highest three concentrations tested. Female dock leaf beetles were also repelled by the lowest concentration tested, where individual components could have occasionally attracted insects. These results indicate a difference in responses to individual compounds and mixtures of compounds.

Effects of applying safe methods for protecting fruit plantations from pests

The broad definition of biological suppression of pests, i.e. the use of various organisms or products of their vital activity to cause damage to a harmful insect, includes many new unique and promising methods. Understanding the need for further study of the biology and ecology of harmful insects and their current potential natural enemies resulted in a number of new methods. They, in turn, led to the emergence of terms such as regulated pest control, bioecological control, an integrated control method, ecologized and ecological plant protection, and pest control systems. The components and methods of biological control used and studied now include parasitoids, predators, various pathogenic agents, and in addition, pheromones, attractants and hormones. Based on traditional objects used in the biomethod, genetically modified organisms are created that can independently resist phytophages. Ecologically safe methods of protecting plants from pests and diseases are everywhere included in agricultural practice, and systems of organic farming are being actively introduced. Thus, studies on the use of safe methods for plant protection from pests in relation to specific climatic and geographical conditions are relevant. In this regard, the current paper presents the results of a study of the effectiveness of Shin-Yetsu dispensers in relation to the conditions of cultivation of fruit trees in the North Caucasus region.

Essential Oil Headspace Volatiles Prevent Invasive Box Tree Moth (Cydalima perspectalis) Oviposition-Insights from Electrophysiology and Behaviour.

The box tree moth (Cydalima perspectalis Walker) is an invasive species in Europe causing severe damage both in natural and ornamental boxwood (Buxus spp.) vegetation. Pest management tactics are often based on the use of chemical insecticides, whereas environmentally-friendly control solutions are not available against this insect. The application of essential oils may provide effective protection against oviposition and subsequent larval damage. Oviposition deterrence of cinnamon, eucalyptus and lavender essential oils was tested on female C. perspectalis in behavioural bioassays. Our results indicate that all the studied essential oils may be adequate deterrents; however, cinnamon oil exhibited the strongest effect. To determine the physiologically active compounds in the headspace of the essential oils, gas chromatography coupled with electroantennography recordings were performed in parallel with gas chromatography-mass spectrometry to identify the volatile constituents. In addition, the release rates of various components from vial-wick dispensers were measured during the oviposition bioassay. These results may serve as a basis for the development of a practical and insecticide-free plant protection method against this invasive moth species.

Efficiency of biological and chemical inducers for controlling Septoria tritici leaf blotch (STB) on wheat (Triticum aestivum L.)

The hemibiotrophic fungus Zymoseptoria tritici is the causative agent of Septoria tritici leaf blotch (STB) disease of wheat (Triticum aestivum L.), the economically most damaging disease of wheat in Europe. Today, ecofriendly plant protection methods compatible with sustainable agriculture are strongly desirable. Here, we tested two chemical inducers β-aminobutyric acid (BABA) and benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) and the two biotic inducers Pseudomonas protegens CHA0 (CHA0) and P. chlororaphis PCL1391 (PCL) for their ability to induce resistance against STB in wheat seedlings. At 21 days after inoculation, only plants treated with BABA showed a smaller area covered by lesions and less pycnidia compared to the untreated control plants. We evaluated spore germination and fungal development on inoculated wheat leaves at early infection stages using calcofluor white staining. Overall, spores of Z. tritici germinated less on plants soil-drenched with BABA and BTH and their hyphal growth was significantly delayed. On the contrary, CHA0 and PCL seed treatments did not affect fungal growth in wheat leaves. In conclusion, BABA efficiently enhanced plant resistance to Z. tritici, BTH delayed fungal development at early stages while the two biotic inducers did not influence the resistance against STB disease.

Advances in the Assortment of Insecto-Fungicides

The paper gives a snapshot of primary trends in improving the chemical method of plant protection, including the development and advancement in such a promising group of preparations as insecto-fungicides. The goal of the work is a qualitative and quantitative analysis of the assortment of insecto-fungicides included in the Catalog of Pesticides and Agrochemicals approved for use in the Russian Federation (hereinafter the Catalog) for the period from 2009 to 2018 and their characterization. The paper also presents information about active ingredients of insecto-fungicides and their brief characteristics, spectrum of activity, and distinctive features and shows prospects for the development of combination preparations as a principal direction toward improving the range of plant-protection products with insecticidal and fungicidal properties. Trends of change are highlighted in the assortment of insecto-fungicides. The application of such combination preparations makes it possible to reduce the rate of application and toxicity and stabilize the duration of the protection against the most dangerous pests and diseases in the most important crops. Therefore, this group of preparations has been shown to contribute to the probability of preserving the crop yield, which will meet sanitary and hygienic standards with the minimal effects on the environmental compartments of agrocenosis.

Survey of entomopathogenic nematodes and fungi in agricultural areas

In 2016-2018, in north-western Poland, field studies were carried out on the coexistence of various taxonomic groups, such as soil nematodes and fungi, including beneficial species that comprise the environment’s natural resistance to pests in agrocenoses. The research aimed to find a connection between select biotic and abiotic factors in the chosen crops which could have practical applications in plant protection. Entomopathogenic nematodes Steinernema feltiae Filipiev, 1934 and entomopathogenic fungi Cordyceps fumosorosea and Metarhizium anisopliae (Metschn.) Sorokin were found to be present in all studied agrocenoses; however, they showed clear preferences for some types of crops or soil. The research shows that the effectiveness of the biological methods of plant protection depends on the selection of the right biopreparations, which strengthen the local populations of the beneficial organisms present in specific agriculture areas.

Plant Viruses Infecting Solanaceae Family Members in the Cultivated and Wild Environments: A Review.

Plant viruses infecting crop species are causing long-lasting economic losses and are endangering food security worldwide. Ongoing events, such as climate change, changes in agricultural practices, globalization of markets or changes in plant virus vector populations, are affecting plant virus life cycles. Because farmer’s fields are part of the larger environment, the role of wild plant species in plant virus life cycles can provide information about underlying processes during virus transmission and spread. This review focuses on the Solanaceae family, which contains thousands of species growing all around the world, including crop species, wild flora and model plants for genetic research. In a first part, we analyze various viruses infecting Solanaceae plants across the agro-ecological interface, emphasizing the important role of virus interactions between the cultivated and wild zones as global changes affect these environments on both local and global scales. To cope with these changes, it is necessary to adjust prophylactic protection measures and diagnostic methods. As illustrated in the second part, a complex virus research at the landscape level is necessary to obtain relevant data, which could be overwhelming. Based on evidence from previous studies we conclude that Solanaceae plant communities can be targeted to address complete life cycles of viruses with different life strategies within the agro-ecological interface. Data obtained from such research could then be used to improve plant protection methods by taking into consideration environmental factors that are impacting the life cycles of plant viruses.

Use of tank mixtures for potato plants protection from Phytophthora infestans and Alternaria solani disease agents

Comprehensive crop protection systems, including disease potatoes, were developed and applied during the 1960s and 1980s. The basic principle underlying them is the need to combine all known methods of protecting plants from different groups of phytopathogens (insects, pathogens, weeds) into a single system of measures. During this period, the chemical method of plant protection against pathogens was intensively developing and in complex systems, it was supposed to combine it with others, mainly agrotechnical and biological. Complex systems were built based on the zonal approach, that is, taking into account the species composition of pathogens and other pathogens affecting potatoes in a given agroclimatic zone.One of the major problems of stable high potato yield is a timely implementation of preventive measures against diseases and pests. Insignificant size of land and low quality planting material, failure to observe rotation of crops leads to accumulation and spread of such disease agents as Phytophthora infestans (Mont.) de Bary and Alternaria solani that can significantly decrease yield by 60% and more unless protection means are applied. It was determined that tank mixture of chemical, biological preparations and growth regulators with chemical Antrakol and growth regulator Humisol was most effective against plants damaged by phytophthora. It was ascertained that combination of chemical Antrakol and growth regulator Humisol was most effective for treatment against Phytophthora infestans and Alternaria solani when damage of different by resistance varieties of potato at blooming stage (maximum development of pathogenic agents) by Phytophthora infestans was 1.4–24.6% and by Alternaria solani 6.8–22.2%.

Biological Activity of Hydrophilic Extract of Chlorella vulgaris Grown on Post-Fermentation Leachate from a Biogas Plant Supplied with Stillage and Maize Silage.

Algae are employed commonly in cosmetics, food and pharmaceuticals, as well as in feed production and biorefinery processes. In this study, post-fermentation leachate from a biogas plant which exploits stillage and maize silage was utilized as a culture medium for Chlorella vulgaris. The content of polyphenols in hydrophilic extracts of the Chlorella vulgaris biomass was determined, and the extracts were evaluated for their antioxidant activity (DPPH assay), antibacterial activity (against Escherichia coli, Lactobacillus plantarum, Staphylococcus aureus, Staphylococcus epidermidis) and antifungal activity (against Aspergillus niger, Candida albicans, Saccharomyces cerevisiae). The use of the post-fermentation leachate was not found to affect the biological activity of the microalgae. The aqueous extract of Chlorella vulgaris biomass was also observed to exhibit activity against nematodes. The results of this study suggest that Chlorella vulgaris biomass cultured on post-fermentation leachate from a biogas plant can be successfully employed as a source of natural antioxidants, food supplements, feed, natural antibacterial and antifungal compounds, as well as in natural methods of plant protection.

Computer Science in Environmental Safety Research

The today’s state-of-the-art chemical plant protection method is cost-effective. However, the environmental safety of this process is questionable. Aerosol pesticides are not targeted; only 5% to 30% of the sprayed dosage is actually deposited on plants, whereas the rest ends up in the soil. Although high-stability pesticides are no longer in use, low- and medium-stability agents have been recorded to render soil toxic to plants. When spraying, large drops exceeding 200 µm roll down to the soil and contaminate it. Smaller droplets (< 100 µm) are gone with the wind. It is imperative to systematically monitor the process of spraying chemical protective agents from the environmental standpoint. As a tool for monitoring and forecasting, this paper proposes a software package that can monitor the spraying process online. The package comprises a data module, a pesticide spraying test module, and a data visualization/storage module. The proposed system provides real-time monitoring of the spraying process and records the concentration of pesticides, whether plant- or soil-deposited; if necessary, the user can make changes in the agent and toolkit database. Field tests have been carried out using this software to identify the environmentally safest spraying system; it generates droplets sized 120 µm, which is necessary for chemical treatment of crops. Other sprayers involved in the experiment either had a drop size >200 µm, which would quickly reach the soil; or <100 µm, which would be quickly dispersed by the wind. Field test data can be further used to optimize the pesticide spraying process.