Disinfection Of Seeds Research Articles

Essential oils of thyme (Thymus vulgaris) and oregano (Origanum vulgare) as an alternative for the control of pesticide-resistant Fusarium spp. in quinoa seeds.

The phytopathogenic genus Fusarium can cause damage such as root and stem rot in economically important crops, with significant implications. To seek a sustainable method for controlling this phytopathogen in seeds, the antifungal activity of essential oils (EOs) from thyme (Thymus vulgaris) and oregano (Origanum vulgare) was evaluated against isolates of F. graminearum, F. equiseti, F. culmorum and F. oxysporum originating from quinoa (Chenopodium quinoa) crops in the Boyacá (Colombia). Initially, the effectiveness of commercial fungicides against the mentioned phytopathogenic fungi was evaluated. Upon verifying that these isolates exhibited high resistance to these compounds, the EOs were assessed as a potential control alternative. A disk diffusion assay demonstrated complete in vitro inhibition of the growth of the evaluated phytopathogens when undiluted EOs were used. Subsequently, the minimum inhibitory concentration (MIC) of these oils was determined using the agar well diffusion technique, revealing a MIC of 10 and 1 μL mL-1 for thyme and oregano oil, respectively. Following this, the antifungal activity of the EOs applied to quinoa seeds was evaluated, and germination indices were measured as an indirect indicator of their toxicity. Despite both EOs successfully inhibiting microbial growth in the seeds, it was also found that thyme EO at 100 μL mL-1 and oregano EO at 10 μL mL-1 inhibited seed emergence and germination. However, lower concentrations exhibited a reduction in fungal population without affecting these germination indices. Therefore, it is suggested that the use of these compounds has potential in the treatment and disinfection of quinoa seeds. © 2024 Society of Chemical Industry.

The influence of soybean rhizobia on the agricultural seeds sowing qualities

To grow high and stable yields with good product quality, it is very important to receive timely, full-fledged and friendly shoots of optimal density. Therefore, the problem of stimulating, or inhibiting, seed germination and the processes occurring in them occupies an important place in modern crop production. The method of pre-sowing seed treatment with rhizobia is one of the promising technological measures that ensure an increase in yield and quality of crop production. The staff of the Laboratory of Biological Research of the Federal State Budgetary Budgetary Institution of the Federal Research Institute of Soy conducted a study of the possibility of stimulating germination and disinfection of soybean seeds, lupin, vigna, wheat, barley using pure Sinorhizobium fredii crops. The work used collectible strains of rhizobia, which showed an abundant growth of bacterial mass on the nutrient medium of the MRC. The standard strain was S. fredii 5851 from the collection of microorganisms and cell cultures of the Leibniz Institute (DSMZ), Germany. In variants with strains, stable stimulating and healing effects were observed. As a result of a scientific experiment, it was found that, on average, in variants with S. fredii strains, germination increased by 37%, the length of seedlings – by 224%, the raw weight of seedlings – by 23% compared with the control (without treatment with strains). S. fredii strains BB-49, SB-39, SB-43, TB-422, TB-488, TB-490, TB-496, 062 maximally stimulated the process of germination of agricultural seeds.

Dosimetry for low-energy electron beam applications at Fraunhofer FEP

Abstract Accelerating electrons to achieve chemical and biological effects is a well-established competence of Fraunhofer FEP. Today, there is a large variety of low-energy electron beam applications with a broad range of absorbed doses, e.g. modification of plastics, plasma-chemical syntheses, pollutant removal in wastewaters and exhaust gases, sterilization of medical products, disinfection of seeds, biocompatible functionalization of implants and stimulation of biotechnological processes. This calls for reliable, sensitive, and flexible methods for dosimetry. Radiochromic films are suitable tools to measure electron dose distributions for the characterization and quality control of Fraunhofer FEP’s irradiation facilities. Risø B3 radiochromic film from DTU Health Tech, the dosimeter of choice at FEP, reliably detects doses in the range of 10–100 kGy. However, with new upcoming applications, doses in the single-digit kGy range and even lower come to the fore. Hence, the palette of dosimeters at FEP must be extended. Gafchromic’s HD-V2 film is a welcome complement and widens the accessible dose range down to 10 Gy. Using a UV-VIS spectrophotometer for read-out of the films and custom analysis algorithms further increase the sensitivity of the dosimetric setup. Additionally, dosimeters based on the optically stimulated luminescence (OSL) of beryllium oxide offer a wide dose range and high sensitivity. They were used to measure doses induced by secondary X-ray components to gain more information about a specific radiation field. The work gives an overview of the dosimetric toolbox at Fraunhofer FEP and the efforts to implement new methods of detection for low-dose applications and X-ray dosimetry.

Towards a standardised orchid germination protocol: determining the optimal duration of chemical scarification for orchid seeds by means of viability and permeability staining

Complex nutrient media are used for the germination of orchids in the laboratory. These substrates are also suitable for the growth of microbes and thus the sterilization of both the medium and the seeds prior to sowing is mandatory. The surface disinfection of orchid seeds with chemical substances eliminates possible infections and enhances germination in several cases, by chemically scarifying their seed coats. However, long durations of chemical treatments may result in viability loss, and consequently, precisely determining the optimal treatment duration is essential for developing effective germination protocols. In this study, the double staining technique with Tetrazolium Chloride and Trypan Blue is tested as a proxy method to determine the optimal chemical treatment duration for 10 orchid taxa of Greece. Various durations of chemical treatment with 5% Ca(OCl)2 were carried out on independent seed samples which were subsequently tested, pairwise, for both germination and viability. The results in the corresponding experiments are extraordinarily similar and we conclude that the double viability staining is a quick and accurate technique in determining the permeability and optimal duration for chemical scarification prior to germination experiments. The storability potential of the taxa studied is discussed in comparison with previous data of the NKUA Seed Bank.

Bacillus strain BX77: a potential biocontrol agent for use against foodborne pathogens in alfalfa sprouts.

Despite regulatory and technological measures, edible sprouts are still often involved in foodborne illness and are considered a high-risk food. The present study explored the potential of spore-forming Bacillus isolates to mitigate Salmonella and Escherichia coli contamination of alfalfa sprouts. Food-derived Bacillus strains were screened for antagonistic activity against S. enterica serovar Typhimurium SL1344 (STm) and enteropathogenic E. coli O55:H7. Over 4 days of sprouting, levels of STm and E. coli on contaminated seeds increased from 2.0 log CFU/g to 8.0 and 3.9 log CFU/g, respectively. Treatment of the contaminated seeds with the most active Bacillus isolate, strain BX77, at 7 log CFU/g seeds resulted in substantial reductions in the levels of STm (5.8 CFU/g) and E. coli (3.9 log CFU/g) in the sprouted seeds, compared to the control. Similarly, co-culturing STm and BX77 in sterilized sprout extract at the same ratio resulted in growth inhibition and killed the Salmonella. Confocal-microscopy experiments using seeds supplemented with mCherry-tagged Salmonella revealed massive colonization of the seed coat and the root tip of 4-day-old sprouted seeds. In contrast, very few Salmonella cells were observed in sprouted seeds grown with BX77. Ca-hypochlorite disinfection of seeds contaminated with a relatively high concentration of Salmonella (5.0 log CFU/g) or treated with BX77 revealed a mild inhibitory effect. However, disinfection followed by the addition of BX77 had a synergistic effect, with a substantial reduction in Salmonella counts (7.8 log CFU/g) as compared to untreated seeds. These results suggest that a combination of chemical and biological treatments warrants further study, toward its potential application as a multi-hurdle strategy to mitigate Salmonella contamination of sprouted alfalfa seeds.

Impact Analysis of Solar Heater Box with Linear Actuator on Characteristics of Chickpea Seeds

Food security is one of the major concerns of humankind in the present era and a lot of work has been done to ensure the availability of food to the growing population. Post-harvest technology is one of the key components to store the seeds for long duration for consumption as food or grow as seed. The disinfection of seeds during storage from insect pests is one of the major problems that need to be addressed. In this study, an efficient solar box is designed which is operated through renewable solar energy. For this purpose, the solar heater box was prepared of an acrylic sheet (2mm thickness), Lasani sheet (2mm thickness) and hardboard sheet (12mm thickness) which were an octagon in shape with 135oC at the base. A 12v linear actuator was installed in the solar box along with hardwood log (saw tooth-like comb) to equally distribute the heat in the seed place for experiment. The highest thermal performance was generated by an acrylic solar heater box 87.40 ℃ compared to hardboard and Lasani box. However, the material used for assembling acrylic boxes was too costly. A hardboard box was too heavy and the temperature was generated 69.69℃ which was relatively significant to the temperature recorded in Lasani solar heater box (70.19℃) at after 6 hour of an observation. Concerning the financial aspect, the price of each of the three solar heater boxes was estimated based on the cost of the materials used to construct the boxes and the additional labour costs, with the assistance of carpenters during assembly. These costs show how much cheaper the Lasani box is compared to the other prototypes. The temperature at a depth of 6 cm was noted 67.42℃ among Chickpea seeds, whereas the temperature recorded within seeds was 69.61℃. Furthermore, the experiment conducted in RCBD revealed that germination percentage of seeds at a depth of 6cm was observed to be 97% after treatment. The overall conclusion of the study is that the solar box with linear actuator is more efficient as compared to traditional drying method.

Study on the process automatization of wetting (moistening) the seeds using a step motor

Researcher Urishev was the first to deal with the issues of mechanization of the process of moistening cotton seeds in the Republic of Uzbekistan. He also developed many devices and mechanisms and proposed methods for conducting experiments on moistening pubescent cotton seeds. However, his works did not address the issues of automation of laboratory facilities. And also Urishev used chemicals for seed treatment, which is harmful to humans and the environment. The creation of an environmentally friendly technology for presowing disinfection of cotton seeds is an urgent task for cotton growing. Research in this field of science has led to the use of electrical energy as the most harmless and cheap means. Along with researchers studying electrical technology in the Republic of Uzbekistan, under the guidance of Professor Mukhammadiev, research work has been carried out since 1985: to develop a non-chemical technology for growing cotton using a spark discharge current, an alternating electric current of industrial frequency. In this article, the possibilities of automating the process of lifting and lowering a laboratory test mechanism for studying the friction of dry and moist cotton seeds proposed by Urishev with the help of a stepper motor were studied in order to automate the process of laboratory experiments. We also obtained equations for finding the resulting force.

The calculation and choice of the electromagnet parameters for the grain and seeds disinfectant device

BACKGROUND: High infection rate of grain harvest, produced in Russia annually, by causative agents of fungal and bacterial diseases, causing significant quantitative losses of grain and decreasing of storage quality, revealed low efficiency of operation of chemical treatment, nowadays widely used in production for disinfection of grain and seeds. Therefore, development of electrophysical disinfection methods, which are environmentally friendly and effective against fungal and bacterial infections, as well as development of technical devices for their implementation is a relevant scientific and production problem.
 AIMS: Development of method of choice and definition of reasonable parameters of alternating current generator and electromagnet of disinfectant device for grain and seeds.
 METHODS: The study subjects are methods and conditions of generation of alternating magnetic fields in the operational volume of impact on grain seeds flow. The study method is analysis of laws of electromagnetism and adaptation of them to the process of definition of electromagnet parameters for the operational volume of the disinfectant device. The study materials include the adapted mathematical expressions of magnet winding parameters and the method of their use.
 RESULTS: For the sake of implementation of the new method of grain and seeds disinfection from causative agents of fungal and bacterial diseases by alternating magnet field, two methods of choice and calculation of electromagnet, which is the key element of the disinfectant device, have been developed. The first method comes to reasonable use of properties of a chosen generator by means of definition of coil winding parameters, ensuring demanded field density. Coil dimensions and time of impact on seeds will determine the device performance for treated grain. In the second method, the capacity of material flow through operational chamber (in the electromagnet) is conditioned by operational needs. It determines the size, parameters and operational modes of chamber (the inductance coil), ensuring the field demand, enough for disinfection, that, in the end, defines the properties of the generator.
 CONCLUSIONS: The suggested method makes it possible to accelerate the development of facilities for implementation of highly efficient, energy saving and environmentally friendly technology of low-frequency magnetic disinfection of grain and seeds and to incorporate it in agricultural production.

Investigation of seed distribution on the surface of the depositing electrode from the grain material supply in the process of seed disinfection in electric fields

Purpose. Determination of technical and technological parameters of the electrotechnological means for presowing disinfection and stimulation of seeds in the electric field depending from the coefficient of distribution of seeds of crops on the surface of the precipitating rotating electrode. Methods. Analytical and calculation method using the structural and technological parameters of the working area of the means for pre-sowing disinfection and stimulation of seeds in an electric field and the data on the physical and mechanical properties of crop seeds. Results. A prototype of an electrotechnological device for pre-sowing disinfection and stimulation of crop seeds by a complex of electrophysical actions has been developed. The main condition for effective disinfection of seeds on the surface of a disk electrode in a high voltage electric field is the turning of the grains in the working space of the electrode system and their uniform distribution by the thickness of the grains in one layer on the surface of the rotating depositing electrode. This movement of the seed masses on the moving electrode ensures uniform treatment of each grain, which increases the efficiency of the process of disinfection of seed and grain material. To implement the process of pre-sowing disinfection and stimulation of seeds in an electric field, a structural and technological scheme of seed feeding and distribution in the working area of the electrode space of the device was developed Analytical dependences of feeding, expected productivity, and design parameters of the device scrapers on the coefficient of distribution of crop seeds on the surface of the depositing rotating electrode were obtained. They allow us to establish what the seed supply to the surface of the depositing electrode should be, and, accordingly, the performance of the prototype and the parameters of the scraper system to ensure the turning of the seeds in space and their uniform distribution by the thickness of the seeds in one layer on the surface of the rotating depositing electrode. Conclusions 1. The dependence of the supply of crop seeds to the surface of the electrode in terms of the expected productivity of the plant on the coefficient of seed distribution kz in the working area of processing was established. The distribution of seeds on the electrode surface in terms of specific gravity depends on the supply of seeds to the disk, the height and length of the scrapers. Uniform distribution of wheat, soybeans, corn, sunflower seeds on the surface of the disk in a single layer is achieved when kz = 1. In this case, the seed supply to the disk is in the range of 0.3–0.6 kg/s. 2. The parameters of the scraper system in terms of the length and height of the three scrapers depended on the type of crop seeds and their supply to the working area of the electrode system. The length of the first scraper for different seeds was in the range of values 229–246 mm, height – 18–24 mm; the second – 164–181 mm and 36–47 mm; the third - 83–132 mm and 54–71 mm, respectively. The specific weight of seeds on the surface of the disk is 1.3–3.7 kg/m2. The expected productivity of the prototype of the electrotechnological means for seeds of agricultural crops will be in the range of 0.7–2.1 t/h. Keywords: seed distribution coefficient, scraper system, seed disinfection, electric field, productivity, feeding, electrotechnological installation, pathogenic microflora, molds

Влияние свето-импульсной обработки семян рапса ярового на лабораторную всхожесть и семенную инфекцию

The article presents the results of research on determining the impact of light pulsed ultraviolet radiation of "Ecosvet-1" device with different intensities (4, 8, 16, and 32 kJ/m2) on laboratory germinating ability of spring rapeseed variety Tavrion and its infestation by pathogenic microorganisms. The experiment was conducted at V.S. Pustovoit All-Russian Research Institute of Oil Crops in 2022. We determined the laboratory germination of seeds of rapeseed according to State Standard 12038-84 in Petri dishes in a humidity chamber, and the infestation by the diseases – according to State Standard 12044-93. Laboratory germination of rapeseed seeds in the control was 63.0%. The cause of the germination decrease was affection by fungi of the genera Alternaria Nees and Fusarium sp. Link, as well as by bacteria of the genera Pseudomonas Migula and Xanthomonas Dowson. As a result of the treatment of rapeseed seeds with a noninvasive polychromatic light pulse, there was an increase in laboratory germination by 6-16 % compared to the control due to a decrease in seed infection. According to the obtained data, the best result in the experiment showed the variant with a specific dose of ultraviolet radiation (SD UV) of 8 kJ/m2. Laboratory germination of seeds in this variant was 79.0%. All seedlings from normally germinated seeds were healthy. The prevalence of Alternaria blight was 2 times lower on non-germinated seeds than on the control, Fusarium blight – 3 times lower, and bacterial blight – 1.5 times lower. The obtained data suggest that this method is promising for the presowing disinfection of rapeseed seeds from pathogenic microflora.

CONTAMINATION OF SEEDS AND PLANTS OF WHEAT WITH PHYTOPATOGENES OF FUSARIUM GENUS, METHODS OF RECOVERY

Widespread production of grain crops and rejection of classical tillage technology have led to a noticeable increase of harmfulness of phytopathogens. First of all, this appertains to facultative parasites with a wide specialization - Bipolaris spp., Fusarium spp., as well as to secondary fungi from Alternaria spp., Cladosporium spp., Penicillium spp. genera and others. There is a simultaneous change of dominance in microbial community of seeds obtained in the Trans-Urals. Fungi of Fusarium spp. genus occupied the leading place among the most harmful pathogens, placing Bipolaris sorokiniana Sacc. Shoem. to the background. F. oxysporum (Schleht) Snyd, F. graminearum Schwabe, F. sporotrichoides Sherb are most spread on spring wheat, both in the tillering phase and at milk-wax stage of grain ripeness. The abundance and diversity of species was significantly higher in the tillering phase than when counted at the end of the vegetation season. To reduce the spread and development of any phytopathogen, it is necessary to apply a set of measures. One of the most effective measures is pre-sowing disinfection of seeds. However, the proposed preparations are not all equally effective in suppressing the development of the fungus of Fusarium spp. genus. During the experiment, it was found that seed treatment fungicides from the class of benzimidazoles - Zim (carbendazim), mixtures of active substances from the classes of triazoles with imidazole - HYIP (triticonazole + prochloraz), and also two triazoles - Oplot (difenoconazole + tebuconazole) were distinguished by high activity from 5.2 to 7.5 units. Application of a microbiological preparation (Bacillus subtilis), as well as its mixtures with a reduced application rate of a chemical disinfectant, showed the absence or low inhibition of fungus mycelium development.

Analytical Assessment and Consideration of the Properties of Electromagnetic Fields in Agro-disinfection Devices

Studies have been carried out to assess the properties of electromagnetic fields used in the disinfection of grain and seeds. Cause-and-effect relationships between the non-monochromaticity of the field and the shortcomings of microwave and other methods of disinfection have been established. For a better result, it is proposed to use monochromatic working fields, the advantages of which are demonstrated by the example of a new method of resonant low-frequency disinfection. An analysis of the electric and magnetic components of the field in the output device was performed, based on the results of which an effective technical solution based on the electric component was proposed. The superiority of a device with an electrical component over a solenoid has been experimentally confirmed.

ИССЛЕДОВАНИЕ ГИДРОДИНАМИКИ В УСТАНОВКЕ БАРАБАННОГО ТИПА ДЛЯ ДЕЗИНСЕКЦИИ СЕМЯН ЗЕРНОВЫХ КУЛЬТУР

The article presents the results of a study of hydrodynamics in a drum-type installation for the dis-infection of grain seeds by an ionized flow of an aerodisperse mixture. In the course of the re-search, a calculation scheme was drawn up and an equation was obtained to determine the throughput of the installation. Graphical dependences of the hydrodynamic coefficient, taking into account the influence of the velocity of the ionized aerodisperse mixture, on the equivalent Reyn-olds criterion for some cereals are given, and the nature and regularity of these dependences are established.

Tomato brown rugose fruit virus: An emerging and rapidly spreading plant RNA virus that threatens tomato production worldwide.

Tomato brown rugose fruit virus (ToBRFV) is an emerging and rapidly spreading RNA virus that infects tomato and pepper, with tomato as the primary host. The virus causes severe crop losses and threatens tomato production worldwide. ToBRFV was discovered in greenhouse tomato plants grown in Jordan in spring 2015 and its first outbreak was traced back to 2014 in Israel. To date, the virus has been reported in at least 35 countries across four continents in the world. ToBRFV is transmitted mainly via contaminated seeds and mechanical contact (such as through standard horticultural practices). Given the global nature of the seed production and distribution chain, and ToBRFV's seed transmissibility, the extent of its spread is probably more severe than has been disclosed. ToBRFV can break down genetic resistance to tobamoviruses conferred by R genes Tm‐1, Tm‐2, and Tm‐2 2 in tomato and L 1 and L 2 alleles in pepper. Currently, no commercial ToBRFV‐resistant tomato cultivars are available. Integrated pest management‐based measures such as rotation, eradication of infected plants, disinfection of seeds, and chemical treatment of contaminated greenhouses have achieved very limited success. The generation and application of attenuated variants may be a fast and effective approach to protect greenhouse tomato against ToBRFV. Long‐term sustainable control will rely on the development of novel genetic resistance and resistant cultivars, which represents the most effective and environment‐friendly strategy for pathogen control.Taxonomy Tomato brown rugose fruit virus belongs to the genus Tobamovirus, in the family Virgaviridae. The genus also includes several economically important viruses such as Tobacco mosaic virus and Tomato mosaic virus.Genome and virionThe ToBRFV genome is a single‐stranded, positive‐sense RNA of approximately 6.4 kb, encoding four open reading frames. The viral genomic RNA is encapsidated into virions that are rod‐shaped and about 300 nm long and 18 nm in diameter. Tobamovirus virions are considered extremely stable and can survive in plant debris or on seed surfaces for long periods of time.Disease symptomsLeaves, particularly young leaves, of tomato plants infected by ToBRFV exhibit mild to severe mosaic symptoms with dark green bulges, narrowness, and deformation. The peduncles and calyces often become necrotic and fail to produce fruit. Yellow blotches, brown or black spots, and rugose wrinkles appear on tomato fruits. In pepper plants, ToBRFV infection results in puckering and yellow mottling on leaves with stunted growth of young seedlings and small yellow to brown rugose dots and necrotic blotches on fruits.

Establishment of a Pre-Drying Methods for Hot Water Disinfection of Rice Seeds at a High Temperature

Establishment of a Pre-Drying Methods for Hot Water Disinfection of Rice Seeds at a High Temperature

To the question of controlling insect pests of seed grain when stored in sealed vessels

During grain storage, pests cause significant harm. Their larvae gnaw through the shell of the grain and penetrate inside, where they feed on the endosperm. Currently, when fighting against such pests, the technologies of forced cooling of the grain mound and disinfection of seeds using insecticides are used. Both of these technologies are not widely used in grain production, due to significant material and energy costs for the purchase and maintenance of special equipment. Moreover, the second technology is environmentally hazardous, since it uses substances polluting the environment. Now many scientists are engaged in studying ecologically safe methods of fighting with pests. One of such methods is grain treatment with ozone. However, this method is not used due to the lack of recommendations for the use of this gas and the need for some additional equipment for gas production. To ensure the metabolic process in their body, pests need to consume oxygen from the environment in much larger volumes than the seeds of cereals need. A promising method for protecting seeds from pests is a method based on limiting the process of slowing down the metabolism of pests by limiting the consumption of oxygen from the environment. This article is devoted to the results of studying this method.

The Method of Resonant-Low-frequency Disinfection of Grain: Biophysical Substantiation and Innovative Advantage

A new method of disinfection of grain and seeds using resonant-lowfrequency electromagnetic oscillations, characterized by simplicity of equipment, economy, safety, uniform quality of sterilization, has been proposed. The processing method and its advantages are theoretically substantiated. A holistic biophysical model has been obtained that gradually reflects the process of disinfection, which illustrates the advantages of the method that are unattainable for other methods of disinfection.

Investigation of the disinfecting properties of low-frequency electromagnetic oscillations

The drawbacks of the existing methods of disinfection of grain and seeds are shown, a conclusion is made about the absence of a highly effective “green” method, which may be based on low frequency electromagnetic oscillations (up to 1 kHz), which have an inhibitory me chanism. The possibility of deep disinfection and an increase in laboratory germination of seed satcertain low frequencies has been investigated; thanks to their directional (resonant) action, energy savings and other advantages are achieved.

Applications of Cold Atmospheric Pressure Plasma Technology in Medicine, Agriculture and Food Industry

In recent years, cold atmospheric pressure plasma (CAPP) technology has received substantial attention due to its valuable properties including operational simplicity, low running cost, and environmental friendliness. Several different gases (air, nitrogen, helium, argon) and techniques (corona discharge, dielectric barrier discharge, plasma jet) can be used to generate plasma at atmospheric pressure and low temperature. Plasma treatment is routinely used in materials science to modify the surface properties (e.g., wettability, chemical composition, adhesion) of a wide range of materials (e.g., polymers, textiles, metals, glasses). Moreover, CAPP seems to be a powerful tool for the inactivation of various pathogens (e.g., bacteria, fungi, viruses) in the food industry (e.g., food and packing material decontamination, shelf life extension), agriculture (e.g., disinfection of seeds, fertilizer, water, soil) and medicine (e.g., sterilization of medical equipment, implants). Plasma medicine also holds great promise for direct therapeutic treatments in dentistry (tooth bleaching), dermatology (atopic eczema, wound healing) and oncology (melanoma, glioblastoma). Overall, CAPP technology is an innovative, powerful and effective tool offering a broad application potential. However, its limitations and negative impacts need to be determined in order to receive regulatory approval and consumer acceptance.

Evaluation of Seven Essential Oils as Seed Treatments against Seedborne Fungal Pathogens of Cucurbita maxima.

Essential oils are gaining interest as environmentally friendly alternatives to synthetic fungicides for management of seedborne pathogens. Here, seven essential oils were initially tested in vivo for disinfection of squash seeds (Cucurbita maxima) naturally contaminated by Stagonosporopsis cucurbitacearum, Alternaria alternata, Fusarium fujikuro, Fusarium solani, Paramyrothecium roridum, Albifimbria verrucaria, Curvularia spicifera, and Rhizopus stolonifer. The seeds were treated with essential oils from Cymbopogon citratus, Lavandula dentata, Lavandula hybrida, Melaleuca alternifolia, Laurus nobilis, and Origanum majorana (#1 and #2). Incidence of S. cucurbitacearum was reduced, representing a range between 67.0% in L. nobilis to 84.4% in O. majorana #2. Treatments at 0.5 mg/mL essential oils did not affect seed germination, although radicles were shorter than controls, except with C. citratus and O. majorana #1 essential oils. Four days after seeding, seedling emergence was 20%, 30%, and 10% for control seeds and seeds treated with C. citratus essential oil (0.5 mg/mL) and fungicides (25 g/L difenoconazole plus 25 g/L fludioxonil). S. cucurbitacearum incidence was reduced by ~40% for plantlets from seeds treated with C. citratus essential oil. These data show the effectiveness of this essential oil to control the transmission of S. cucurbitacearum from seeds to plantlets, and thus define their potential use for seed decontamination in integrated pest management and organic agriculture.