Treated Tomato Plants Research Articles

The influence of the use of lignohumate on the yield and quality parameters of tomato in vegetable crop rotation

The results of the development of regulations for the use of humic growth stimulants on tomatoes in the vegetable crop rotation fertilizer system are represented in this article. The problem of effective assimilation of mineral fertilizers is central in crop production. The combination of humates with mineral fertilizers is a guarantee of their effective assimilation by the plant. The intensity of growth of tomato plants is considered one of the main indicators of the impact of agricultural practices on plants. Treatment of tomato plants with preparations Lignohumate AM and Humate +7 promotes a more intensive increase in growth rate. Recalculation of tomato yield showed that the use of growth stimulants gives a significant increase. The most effective was Lignohumate AM, the increase was 23.9%. The effectiveness of Humat +7 and Argolan Aqua were at the same level and amounted to 21.8 and 20.3%, respectively. The use of humic preparations stimulated the accumulation of dry matter in tomato fruits from 4.6-4.7% in the control to 4.9-5.1% in the experimental variants. The studied preparations had a positive effect on the productivity and quality indicators of tomato. The economic efficiency of the use of growth stimulants in tomato is high. The net profit from the application of Lignohumate AM amounted to 1,038 thousand rubles, which is 198 thousand rubles higher than the control variant. The profitability is higher than when using Humat +7 and Argolan Aqua by 30 and 42%, respectively. Based on the results of the research, it is recommended to use the humic preparation Lignohumate AM on tomatoes to increase productivity and quality indicators in the conditions of the Central part of the North Caucasian region.

PHYSIOLOGICAL AND BIOCHEMICAL CHANGES OF TOMATO PLANTS UNDER BACTERIAL INFLUENCE

Tomato (Lycopersicon esculentum L) is one of the most important vegetable crops widely grown around the world. However, the global economic productivity of this crop is limited to a number of phytopathogens. Bacterial spotting and mild rot of tomatoes caused by Pseudomonas syringae pv. tomato and Pectobacterium carotovorum subsp. carotovorum, are one of the most common bacterial diseases that cause significant losses and reduce both the quality and quantity of fruits and impair the nutritional value of tomatoes. Tomato plants are affected by these pathogens throughout the growing season, the lesion is characterized by chlorosis, necrosis and rot. The aim of the study was to analyze the impact on the physiological and biochemical parameters of tomato sprouts affected by pathogens of P. syringae pv. tomato and P. carotovorum subsp. саrotovorum. It was found that strains of P. syringae pv. tomato IZ202014 and P. carotovorum subsp. carotovorum IZ207 cause a 30-40% decrease in germination energy and seed germination of Black Prince, Northern Queen, Riddle and Liana tomatoes compared to the control. According to the analysis of physiological and biochemical parameters, the most resistant to pathogens P. syringae pv. tomato, P. carotovorum subsp. carotovorum variety Northern Queen. Treatment of tomato plants with a suspension of the studied strains causes a decrease in chlorophyll content in seedlings by 58-93%. According to the chlorophyll a/b ratio, the Northern Queen and Black Prince varieties have the highest resistance to bacterial damage. Under the influence of cell suspensions of P. syringae pv. tomato IZ202014 and P. carotovorum subsp. carotovorum IZ207 showed changes in the activity of enzymes of the antioxidant system in tomato seedlings, which indicates a decrease in the oxidative processes of cells.

Effect of Neo-Boost Pesticide on Mortality and Development of Different Life Stages of Two-Spotted Spider Mite, Tetranychus urticae

The two-spotted spider mite,Tetranychus urticae, is a polyphagous agricultural pest that feeds on over a thousand plant species and more than 150 crops. Its status as an agricultural pest is exacerbated by its outstanding potential to evolve resistance to pesticides. The existence of multiresistant mite populations challenges mite management and creates a need for the development of pesticides with novel modes of action. In this study, we evaluated the acaricidal activity of Neo-Boost, a pesticide registered as a bactericide/fungicide/insecticide/miticide. Neo-Boost formulation contains three active ingredients: potassium silicate, sodium percarbonate and tetraacetylethylenediamine. In contact with water, the latter ingredients generate peroxyacetic acid, a potent contact bactericide and fungicide. Using the recommended field dose, we tested contact and residual effects of Neo-Boost onT. urticaeegg, larval, and adult life stages. We found that Neo-Boost had no ovicidal effect. When tested on larvae, Neo-Boost caused 87% mortality over 48 hours post-treatment that was comparable to the positive control AGRI-mek SC (active ingredient abamectin), in addition to delaying larval developmental progression. On adult mites, Neo-Boost acted as a deterrent and caused 35% mortality (an intermediate effect compared to the positive control AGRI-mek SC). We also tested the proposed ability of Neo-Boost to induce a systemic response, however, it had no priming effect on treated tomato plants against mites. Of the individual Neo-Boost components tested, peroxyacetic acid and potassium silicate were not effective in any assay. However, sodium percarbonate, surfactant, and other non-listed components were sufficient for the full effectiveness of Neo-Boost formulations. Additionally, phytotoxicity of Neo-Boost was rare and minor when it occurred. Overall, despite the inefficiency of some compounds, the Neo-Boost formulation, either in its original or simplified formulation, may be useful for mite control on crops that are destined for fresh human consumption or medicinal use.

Nondestructive nitrogen content estimation in tomato plant leaves by Vis-NIR hyperspectral imaging and regression data models.

The present study aims to estimate nitrogen (N) content in tomato (Solanum lycopersicum L.) plant leaves using optimal hyperspectral imaging data by means of computational intelligence [artificial neural networks and the differential evolution algorithm (ANN-DE), partial least squares regression (PLSR), and convolutional neural network (CNN) regression] to detect potential plant stress to nutrients at early stages. First, pots containing control and treated tomato plants were prepared; three treatments (categories or classes) consisted in the application of an overdose of 30%, 60%, and 90% nitrogen fertilizer, called N-30%, N-60%, N-90%, respectively. Tomato plant leaves were then randomly picked up before and after the application of nitrogen excess and imaged. Leaf images were captured by a hyperspectral camera, and nitrogen content was measured by laboratory ordinary destructive methods. Two approaches were studied: either using all the spectral data in the visible (Vis) and near infrared (NIR) spectral bands, or selecting only the three most effective wavelengths by an optimization algorithm. Regression coefficients (R) were 0.864±0.027 for ANN-DE, 0.837±0.027 for PLSR, and 0.875±0.026 for CNN in the first approach, over the test set. The second approach used different models for each treatment, achieving R values for all the regression methods above 0.96; however, it needs a previous classification stage of the samples in one of the three nitrogen excess classes under consideration.

A Bifunctional Synthetic Peptide With Antimicrobial and Plant Elicitation Properties That Protect Tomato Plants From Bacterial and Fungal Infections.

The hybrid peptide BP178 (KKLFKKILKYLAGPAGIGKFLHSAKKDEL-OH), derived from BP100 (KKLFKKILKYL) and magainin (1–10), and engineered for plant expression, had a strong bactericidal activity but not fungicidal. Moreover, the preventive spray of tomato plants with BP178 controlled infections by the plant pathogenic bacteria Pseudomonas syringae pv. tomato and Xanthomonas campestris pv. vesicatoria, as well as the fungus Botrytis cinerea. The treatment of tomato plants with BP178 induced the expression of several genes according to microarray and RT-qPCR analysis. Upregulated genes coded for several pathogenesis-related proteins, including PR1, PR2, PR3, PR4, PR5, PR6, PR7, PR9, PR10, and PR14, as well as transcription factors like ethylene transcription factors, WRKY, NAC and MYB, involved in the salicylic acid, jasmonic acid, and ethylene-signaling pathways. BP178 induced a similar gene expression pattern to flg15 according to RT-qPCR analysis, whereas the parent peptide BP100 did not trigger such as a strong plant defense response. It was concluded that BP178 was a bifunctional peptide protecting the plant against pathogen infection through a dual mechanism of action consisting of antimicrobial activity against bacterial pathogens and plant defense elicitation on plant host.

Anti-Biofilm Activity and Biocontrol Potential of Streptomyces Cultures Against Ralstonia solanacearum on Tomato Plants.

Biological control of phytopathogen is a promising approach when compared to the use of chemical agents. In the present study, seven Streptomyces cultures showing promising anti biofilm activity against Ralstonia solanacearum was mixed individually with farmyard manure. All the Streptomyces fortified farmyard manure (SFYM) were screened for plant growth promotion and control of bacterial wilt caused by R. solanacearum on tomato. Further, the ability of SFYM on stimulating the production of defense-related enzymes in R. solanacearum-inoculated tomato plants was investigated. When compared to the control tomato plants, the SFYM-treated plants had longer shoot and root length along with higher fresh and dry weight. The maximum level of chlorophyll was observed in the plants treated with strain UP1A-1 (2.21 ± 0.18mgg-1). Strain UP1A-1 also showed maximum of 96.8 ± 1.4% biocontrol efficacy in tomato plants challenged with R. solanacearum. In addition, the UP1A-1 treated tomato plants showed maximum accumulation of total phenolics (3.02 ± 0.09mgg-1) after 6days of pathogen inoculation (DPI). Similarly, tomato plants treated with UP1A-1 showed highest level of peroxides, polyphenol oxidase and phenylalanine ammonia lyase during 1-9 DPI. Findings of present study revealed that the Streptomyces culture UP1A-1 fortified farm yard manure could be applied as an eco-friendly alternative to synthetic agents for controlling bacterial wilt in tomato plants.

Bioactivity of oxymatrine and azadirachtin against Tetranychus evansi (Acari: Tetranychidae) and their compatibility with the predator Phytoseiulus longipes (Acari: Phytoseiidae) on tomato

Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) is one of the main tomato pests in several countries, mainly in Africa, and applications of synthetic acaricides are the main strategy for its control. Efficient biopesticides to suppress pest populations, with low toxicity against natural enemies, is highly desirable for integrated pest management. Here, we evaluated under laboratory conditions the effect of azadirachtin- and oxymatrine-based formulations on each development stage of T. evansi and on the adult stage of the predatory mite Phytoseiulus longipes, the single promising predator of this pest. We also assessed the residual effect of these biopesticides on T. evansi under laboratory conditions on leaflets excised from treated tomato plants maintained in a screen-house 1, 5, and 10 days after application. Azadirachtin-based formulations were effective in controlling T. evansi immature stages. Oxymatrine-based treatments controlled T. evansi immatures and adult females faster than azadirachtin-based treatments. Both biopesticides had no effect on T. evansi eggs, but oxymatrine-based treatments were highly efficient on newly hatched T. evansi larvae. Oxymatrine displayed residual activity that controlled T. evansi up to 10 days after application. Azadirachtin formulations caused lower mortality of P. longipes adults (8–28%) and slightly reduced fecundity (24.8–56.1%). In contrast, oxymatrine treatments caused higher mortality (60–88%) of the predator and reduced substantiality its fecundity (73.1–90.7%). Our findings suggest that Azadirachtin and oxymatrine provide effective control of T. evansi. Azadirachtin may be relatively safer to the predatory mites whereas oxymatrine should be used with caution, to avoid suppression of P. longipes.

Improving Growth, Yield, and Quality of Tomato Plants (Solanum lycopersicum L) by the Application of Moroccan Seaweed-Based Biostimulants under Greenhouse Conditions

Background: Seaweed-derived extracts have gained popularity in agriculture as bioproducts with phytostimulatory effects on plant growth and development. Methods: This study assessed the effect of polysaccharide-enriched extracts (PEEs) derived from six Moroccan seaweeds on tomato growth, yield, and fruit quality. PPEs were applied to tomato plants as soil drench in a greenhouse experiment. Growth parameters including plant height (cm) and number of leaves, flowers, and flower buds were recorded every 15 days. Yield and quality parameters of the harvested fruits were also recorded after each harvest. Results: The obtained results showed that all PEEs improved the growth, yield, and fruit quality of treated tomato plants. According to principal component analysis, the presence of SO4, galactose, glucose, and maltose in the characterized polysaccharides was closely associated with their effect on plant growth, yield, and fruit quality parameters. Conclusions: PEEs obtained from Gelidium crinale,Schizymenia dubyi, Fucus spiralis, and Bifurcaria bifurcata exhibited the highest biostimulant effects and could be used as bioproducts for improved tomato yield and fruit nutritional quality.

Wuxal amino (Bio stimulant) improved growth and physiological performance of tomato plants under salinity stress through adaptive mechanisms and antioxidant potential.

In the present study, ameliorative capabilities of wuxal amino (bio stimulant) under salt stress has been investigated through adaptive mechanisms and antioxidant potential in tomato plants. In the experiment, two different concentrations (2 cm L-1 and 3 cm L-1) of wuxal amino through foliar application and soil irrigation were applied to the salt (150 mM) treated tomato plants and then morphological traits, photosynthetic pigments, osmolytes, secondary metabolites, oxidative stress and antioxidant enzymes activity were assessed at 60 days after planting. The results revealed that salt stress decreased the growth parameters, photosynthetic pigments, soluble sugars and soluble protein whereas, content of proline, ascorbic acid, total phenols, malondialdehyde, hydrogen peroxide and the activity of antioxidant enzymes activity increased under salt stress. Moreover, Wuxal amino application through foliar or soil to salt stressed plants improved morphological traits, photosynthetic pigments, osmolytes, total phenol and antioxidant enzymes activity. Interestingly, the deleterious impact of salinity on tomato plants were significantly reduced and it can be evident from reduced MDA and H2O2 levels. These responses varied with the mode (foliar or soil) of application of Wuxal amino under different concentrations (2 cm L-1 and 3 cm L-1). It was concluded that application of Wuxal amino (2 cm L-1, foliar) and (3 cm L-1; soil) proved best and could be commercially used as eco-friendly tool for the protection of tomato plants grown under salinity stress.

Biochar amendment improves shoot biomass of tomato seedlings and sustains water relations and leaf gas exchange rates under different irrigation and nitrogen regimes

Biochar amendment has many benefits for improving soil water holding capacity and plant growth particularly under reduced irrigation regimes, yet the underlying biochemical and physiological mechanisms remain largely elusive. The combined effects of biochar addition and deficit irrigation under two N fertilizer regimes on tomato plant growth and physiology were investigated. The results showed that, despite a negative effect on leaf N content, biochar amendment improved the plant water status and leaf gas exchange rates under deficit irrigation, thereby enhanced the biomass (DM) of tomato plants irrespective of N regimes. Even though biochar amendment tended to reduce instantaneous water use efficiency, it significantly enhanced plant water use efficiency (WUEp). Biochar increased soil pH and resulted in an increase in xylem pH, which however did not amplify the root-to-shoot ABA signalling inducing early stomatal closure during deficit irrigation. The principal component analysis (PCA) plot showed that plant water use (PWU) rather than WUEp contributed significantly to the enhanced DM under biochar amendment. Thus, the greater stomatal conductance and transpiration rate and consequently the higher PWU as exemplified by the lowered leaf δ13C and δ18O values might have contributed to the increased DM of the biochar treated tomato plants. It is concluded that biochar amendment could be a promising practice to enhance tomato seedling growth under reduced irrigation and N fertilization regimes.

Flowering gene regulation in tomato plants treated with brown seaweed extracts

Liquid extracts of several seaweeds possess great potential as biostimulants for use in agricultural plants. Numerous studies have provided evidence of improved growth and yield parameters in crop plants treated with seaweed extracts. Still, there is a shortage of information available on the mechanisms of action of these extracts on plant growth processes. Enhanced flowering is one of the improved parameters often reported in seaweed extract treated plants for which the mechanisms are yet to be elucidated. In the current study, foliar application of brown seaweed extracts from A. nodosum and Sargassum sp. has significantly increased the flower bud, flower, and fruit number in treated tomato plants. In an effort to understand the molecular basis for enhanced flowering, a transcriptional analysis was carried out to determine the effect of treating tomato plants with two brown seaweed extracts on the expression levels of important flowering genes. Total RNAs were extracted from the apical shoots, floral buds, and flowers at weekly intervals between two and eight weeks. Quantitative Polymerase Chain reaction was used to determine the gene expression levels of six major flowering genes, including Single Flower Truss (SFT), Self-Pruning (SP), Jointless (J), Anantha (AN), Falsiflora (FA) and Constans-1 (CO). The results of the study revealed increased levels of expression of all six flowering genes when treated with either A. nodosum or Sargassum sp. alkaline extracts. Specific enhancements of gene expressions varied between the two treatments over the time intervals. The present study provides evidence of the potential role of seaweed extracts on an enhanced flowering phenomenon observed in tomato which helps justify the sustainable use of seaweed extracts in horticultural crops.

The Antifungal Activity of Gallic Acid and Its Derivatives against Alternaria solani, the Causal Agent of Tomato Early Blight

Tomato (Solanum lycopersicum L.) is among the most important vegetable crops worldwide. Early blight disease, caused by Alternaria solani, is a destructive foliar disease of tomato and other Solanaceae species. Herein, we investigated the in vitro antifungal properties of gallic acid and two of its derivatives (syringic and pyrogallic acids) against A. solani during 2019 and 2020 seasons. The physiological and biochemical effects of these compounds on infected tomato plants were also investigated using the whole plant bioassay. The in vitro investigation showed that all tested compounds showed fungistatic action and inhibited the mycelial radial growth of A. solani in a dose-dependent manner. In two separate pot-experiments, those compounds efficiently suppressed the development of the disease symptoms and area under disease progress curve (AUDPC), without any phytotoxic effects on the treated tomato plants. Additionally, all tested compounds positively enhanced the biochemical traits of treated plants including the chlorophyll content, the total soluble phenolics, the total soluble flavonoids, and the enzymatic activities of catalase, peroxidase, and polyphenol oxidase during 2019 and 2020 seasons. Moreover, the treatment with gallic acid and its derivatives significantly increased all yield components of A. solani-infected tomato plants such as the total number of flowers and fruits, and the fruit yield for each tomato plant in both experiments. Considering the fungitoxicity of phenolic acids against A. solani with no phytotoxicity on treated tomato plants, we believe that gallic acid and its derivatives might be a sustainable eco-friendly control strategy to reduce the usage of chemical fungicides partially or entirely against A. solani particularly, and fungal diseases in general.

Induced Tomato Resistance Against Bemisia tabaci Triggered by Salicylic Acid, β-Aminobutyric Acid, and Trichoderma.

Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) biotype B is a key pest of Solanum lycopersicum L. (Solanaceae) throughout the world. In this study, we examined the induction of resistance on tomato plants treated with SA, BABA, and Trichoderma either individually or in combination against B. tabaci biotype B through the assessment of some biological and behavioral aspects of this insect pest. Also, to understand the mode of action of these inducers, we correlated and analyzed the biochemical basis of plant resistance, by measuring levels of polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), and phenolic content in leaves of treated tomato plants. The longest development time of whitefly immature stages was recorded for plants treated with root β-aminobutyric acid application (RBABA) + root Trichoderma application (RT), root salicylic acid application (RSA) + RT, and RT. In a free-choice assay, B. tabaci adults showed a significantly lower preference for settling and oviposition in RBABA + RT, RSA + RT, and RT in comparison with control. In a no-choice assay, B. tabaci females laid significantly fewer eggs on treatments than those in control, with better results observed in RBABA + RT. Plants responded to different treatments and showed higher induction of PPO, POD, and PAL activities, besides the higher accumulation of phenols in RBABA + RT, RSA + RT, and RT treatments. These results suggest that RBABA + RT, RSA + RT, and RT could be utilized for the induction of effective plant defense against B. tabaci.

Leaf extract of Rhizophora apiculata as a potential bio-inducer of early blight disease resistance in tomato plant

Tomato (Lycopersicon esculentum Mill.) is one of the most remunerative and widely grown vegetables in the world. Tomato has ranks second next to potato in world acreage, but it has rank first among processing crops. In the present study, tomato plants treated with Rhizophora apiculata as seed treatment at 15% and as foliar spray at 30 and 45 days after treatment (DAT), co-inoculated with the Alternaria solani pathogen, recorded maximum activity of the defense related enzymes and PR proteins including; peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), catalse, chitinase and β- 1,3 glucanses. Induction of these defense enzymes was studied in vivo in treated tomato plants grown in the greenhouse. Moreover, the healthy control tomato plants also showed slight increase in activities of all these defense enzymes up to four days, and thereafter showed gradual decline. The aim of the present investigation was to access the induction of the defense enzymes and PR-proteins in tomato plants infested with A. solani, through the application of R. apiculata extract. Accordingly, we can reduce the incidence of early blight disease in these tomato plants. Current findings recorded the earlier and higher accumulation of the defense enzymes and PR-proteins mainly; PO, PPO, PAL, β- 1, 3 glucanse and chitinase in tomato plants, resulting in significant reduction in early blight infection.

Metabolomics to Exploit the Primed Immune System of Tomato Fruit.

Tomato is a major crop suffering substantial yield losses from diseases, as fruit decay at a postharvest level can claim up to 50% of the total production worldwide. Due to the environmental risks of fungicides, there is an increasing interest in exploiting plant immunity through priming, which is an adaptive strategy that improves plant defensive capacity by stimulating induced mechanisms. Broad-spectrum defence priming can be triggered by the compound ß-aminobutyric acid (BABA). In tomato plants, BABA induces resistance against various fungal and bacterial pathogens and different methods of application result in durable protection. Here, we demonstrate that the treatment of tomato plants with BABA resulted in a durable induced resistance in tomato fruit against Botrytis cinerea, Phytophthora infestans and Pseudomonas syringae. Targeted and untargeted metabolomics were used to investigate the metabolic regulations that underpin the priming of tomato fruit against pathogenic microbes that present different infection strategies. Metabolomic analyses revealed major changes after BABA treatment and after inoculation. Remarkably, primed responses seemed specific to the type of infection, rather than showing a common fingerprint of BABA-induced priming. Furthermore, top-down modelling from the detected metabolic markers allowed for the accurate prediction of the measured resistance to fruit pathogens and demonstrated that soluble sugars are essential to predict resistance to fruit pathogens. Altogether, our results demonstrate that metabolomics is particularly insightful for a better understanding of defence priming in fruit. Further experiments are underway in order to identify key metabolites that mediate broad-spectrum BABA-induced priming in tomato fruit.

Induction of drought tolerance in tomato upon the application of ACC deaminase producing plant growth promoting rhizobacterium Bacillus subtilis Rhizo SF 48

A total of ten 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing PGPR isolates were selected and evaluated for the induction of drought stress tolerance in tomato. Among the selected PGPR, maximum seed (laboratory) and plant growth promotion (greenhouse) was observed in tomato seeds bacterized with Bacillus subtilis Rhizo SF 48. The genomic study confirmed the presence of ACC deaminase gene in Rhizo SF 48 and the obtained sequence was deposited to the NCBI database with the Accession No. MK652706. The tomato plants grown upon treatment with Rhizo SF 48 significantly enhanced plant growth even after exposing to different levels of drought stress as compared to stress induced control plants. About 7.5% and 38% increase in RWC were observed in Rhizo SF 48 treated tomato plants grown under well-watered and stress conditions (S4) compared to their control plants, respectively. An increase of 0.76, 0.23 and 0.78 fold in proline, SOD and APX activity and a decrease of 0.3 fold in MDA and H2O2 contents were observed in Rhizo SF 48 treated plants compared to control plants grown under S4 conditions. The histo-chemical studies showed lower accumulations of H2O2 and superoxide anion in the leaves of Rhizo SF 48 treated plants under drought stress, which was in confirmation with the quantification results of H2O2 and SOD. The qRT-PCR studies on drought (Le25) and ethylene responsive factor (SlERF84) marker genes showed that a significant decrease of 0.75 and 0.81 folds, respectively in Le25 and SlERF84 accumulation was observed in Rhizo SF 48 treated plants compared to untreated plants grown under S4 conditions. From the results, it can be attributed that ACC deaminase producing Rhizo SF 48 was able to protect tomato plants against oxidative damage caused due to drought stress and enhanced plant growth promotion. It can be concluded that ACC deaminase producing Rhizo SF 48 can serve as a useful bio-inoculant for sustainable tomato production in arid and semi-arid regions with water deficit.

Uniform application for protection of a tomato from root rots in an open ground of the middle Russia region

Relevance. Significant harm to the culture of tomato, speaking about the middle Russia open ground plantations, is caused by fungal diseases, among which the most common are Fusarium wilt, late blight, alternariosis. To reduce the harmfulness of diseases, it is important to create stable and precocious hybrids that can give most of the crop before the mass development of diseases occurs. The complex system of protection includes preventive measures, the use of growth regulators possessing protective and stimulating action, application of biological preparations and fungicidal treatment. In terms of epiphytotic diseases, the most effective are chemicals, among which the increasing use get multipurpose products, involving several antifungal ingredients.Methods. The article presents the test results of the Uniform fungicide (321,7 g/l Аsoxystrobin + 123,7 g/l to Мefenoxam) against root rot of open ground tomato culture, grown in Moscow region. The estimation of biological and economic efficiency of Uniform application depending on the rate of consumption and multiplicity of treatments was carried out. The tomato Donskoy F1 hybrid, grown on drip irrigation, was used in experiments. Threefold background mode treatment of plants against late blight was carried out by fungicide Revus Top: at the onset of the first symptoms of the disease and hereinafter with 14 days intervals. Flow rate was 0.5 l/ha with solution consumption reaching 200 l/ha. Treatment of tomato plants by Uniform fungicide was performed by watering at the root under the flow rates of 0.9 l/ha and 1.5 l/ha and solution consumption of 200 l/ha. First application of seedlings was performed when planting, the second – 20 days after the first. The area of experimental plots was 20 m2, area of account plots was 10 m2. The repetition of account monitoring was fourfold.Results. The best results were achieved when using Uniform at the rate of 1.5 l/ha by root watering during transplanting and repeatedly at 20 days intervals. An increase in survival rate of seedlings, reduction of incidence of root rot by 81.2-86.9% and tomato yield increase by 29.7% to control under the influence of Uniform treatments were observed.

Bacillus halotolerans strain LYSX1-induced systemic resistance against the root-knot nematode Meloidogyne javanica in tomato

PurposeDetermination of the nematicidal potential and mode of action of bacteria isolated from tobacco rhizosphere soil against the root-knot nematode Meloidogyne javanica in tomato plants.MethodsAntagonistic bacteria were isolated from rhizosphere soil of tobacco infested with root-knot nematodes. Culture filtrate was used to examine nematicidal activity and ovicidal action of bacterial strains. Biocontrol of M. javanica and growth of treated tomato plants were assessed in pot experiments. To clarify whether secondary metabolites of bacteria in tomato roots induced systemic resistance to M. javanica, bacterial culture supernatants and second-stage juvenile nematodes were applied to spatially separated tomato roots using a split-root system. Bacterial strains were identified by 16S rDNA and gyrB gene sequencing and phylogenetic analysis.ResultsOf the 15 bacterial strains isolated, four (LYSX1, LYSX2, LYSX3, and LYSX4) demonstrated nematicidal activity against second-stage juveniles of M. javanica, and strain LYSX1 showed the greatest antagonistic activity; there was dose-dependent variability in nematicidal activity and inhibition of egg mass hatching by strain LYSX1. In vivo application of LYSX1 to tomato seedlings decreased the number of egg masses and galls and increased the root and shoot fresh weight. Treatment of half of the split-root system with LYSX1 reduced nematode penetration to the other half by 41.64%. Strain LYSX1 was identified as Bacillus halotolerans.ConclusionBacillus halotolerans LYSX1 is a potential microbe for the sustainable biocontrol of root-knot nematodes through induced systemic resistance in tomato.

Effect of plant growth regulator, gibberellic acid( GA3) and antibiotic, pencillin in the multiplication of tomato mosaic virus (ToMV)

This experiment was conducted in Biology Department, Science College, University of Al- Anbar in 2018 season, to test the inhibition activity of gibberillic acid and antibiotic, pencillin against tomato mosaic virus.Two compounds were used to investigate resistance induction in tomato plants against the tomato mosaic virus (ToMV). In this study 50 ppm and 100 ppm of gibberillic acid and pencillin respectively were used to identify the activity in the inhibition of virus replicating or inducing the resistance in tomato plants against this virus. The results showed that the concentration 100 ppm of gibberillic acid is the best in the inhibition ratio ( in the experiment of mixture tomato mosaic virus inoculum and gibberillic acid or pencillin). It gave inhibition ratio 67.44 % (lesions number, 0.8133 lesion.cm-2), while the concentration 50 ppm gave inhibition ratio 54.92 % ( lesions number 1.126 lesion.cm-2), Moreover, the concentration 100 ppm of pencillin gave inhibition ratio 79 % ( lesions number, 0.580 lesion.cm-2) in comparison with the concentration 50 ppm which gave 74 % ( lesions number 0.712 lesion.cm-2).The results also showed, when treating tomato plants with the concentration 100 ppm of gibberillic acid by spray on plant, gave inhibition ratio 56.44 % compared with the concentration 50 ppm which give inhibition ratio 33.85 %. Also, the pencillin treatment gave better activity in the concentration 100 ppm which give inhibition ratio 70.494 % , while the concentration 50 ppm gave inhibition ratio 20.038 %.Based on the results of the experiment of immersion tomato roots with gibberellic acid at the concentration 100 ppm was the best, giving inhibition ratio 52.03 % while the 50 ppm of gibberellic acid gave inhibition ratio 26.89 %. Furthermore, when treating the tomato plant with pencillin the resistance against virus was higher at the concentration 100 ppm than at the concentration 50 ppm, which resulted in the inhibition ratios 63.60 % , 41.59 % respectively.The experiment of immersion Datura roots with gibberellic acid and pencillin showed no differences between the concentration 50 ppm of gibberellic acid and control. However, the 100 ppm of gibberellic acid gave inhibition ratio 53.76 %. This experiment did not identify any differences between the antibiotic pencillin concentrations, where the concentration 100 ppm of pencillin gave the highest resistance in plant against the virus with the lowest local lesions on Datura plant (inhibition ratio, 66.267% ) compared with the concentration 50 ppm which gave inhibition ratio, 21.881% and control.

The potential role of some amino acids with different concentrations, application types and times to manage Meloidogyne javanica on tomato plants

In present study four different amino acids i.e. DL-Valine, DL-Methonine, DLAsparagine and DL-Arginine with five different concentrations (50, 100, 150, 200 and 400 mg/ml) and two different application methods (soil drench and foliar spray) at two different application times (three days before and three days after nematodeinoculation) were tested under both laboratory and greenhouse conditions to evaluate their influences on root-knot nematode Meloidogyne javanica and growthcriteria of treated tomato plants. The results revealed that all tested amino acids atconcentration of 400 mg/ml reduced significantly both eggs hatching and juveniles’viability compared to control (nematode treated with tap water) under in vitroconditions. The highest percentage of non-hatched eggs (68%) and dead juveniles(81%) was recorded by DL-Methonine amino acid followed by DL-Asparagine whichpercentage of non-hatched eggs and dead juveniles recorded 60% and 80%,respectively.