Protectant Fungicides Research Articles

Pentachloronitrobenzene Reduces the Proliferative Capacity of Zebrafish Embryonic Cardiomyocytes via Oxidative Stress

Pentachloronitrobenzene (PCNB) is an organochlorine protective fungicide mainly used as a soil and seed fungicide. Currently, there are few reports on the toxicity of PCNB to zebrafish embryo. Here, we evaluated the toxicity of PCNB in aquatic vertebrates using a zebrafish model. Exposure of zebrafish embryos to PCNB at concentrations of 0.25 mg/L, 0.5 mg/L, and 0.75 mg/L from 6 hpf to 72 hpf resulted in abnormal embryonic development, including cardiac malformation, pericardial edema, decreased heart rate, decreased blood flow velocity, deposition at yolk sac, shortened body length, and increased distance between venous sinus and arterial bulb (SV-BA). The expression of genes related to cardiac development was disordered. However, due to the unstable embryo status in the 0.75 mg/L exposure concentration group, the effect of PCNB on the expression levels of cardiac-related genes was not concentration-dependent. We found that PCNB increased reactive oxygen species stress levels in zebrafish, increased malondialdehyde (MDA) content and catalase (CAT) activity, and decreased superoxide dismutase (SOD) activity. The increased level of oxidative stress reduced the proliferation ability of zebrafish cardiomyocytes, and the expressions of zebrafish proliferation-related genes such as cdk-2, cdk-6, ccnd1, and ccne1 were significantly down-regulated. Astaxanthin (AST) attenuates PCNB-induced reduction in zebrafish cardiomyocyte proliferation by reducing oxidative stress levels. Our study shows that PCNB can cause severe oxidative stress in zebrafish, thereby reducing the proliferative capacity of cardiomyocytes, resulting in zebrafish cardiotoxicity.

ジフェノコナゾール剤と保護殺菌剤の混用によるナシ黒星病発病抑制効果

ジフェノコナゾール剤と保護殺菌剤の混用によるナシ黒星病発病抑制効果

Low level of mancozeb exposure affects ovary in mice

Mancozeb (MCZ) is widely used as a protective fungicide. This study aimed to explore the effects of low level MCZ exposure on ovary in mice. Twenty Kunming mice were randomly divided into control and MCZ groups (10 mice each). The mice in the MCZ group were given 100 mg/kg MCZ daily via gavage. The mice were sacrificed to collect serum and ovaries on day 31. The experimental indicators were then assessed. The weight of MCZ-exposed mice significantly reduced while ovarian index significantly increased compared with the control group. The FSH, LH, E2, P, CAT, SOD and MDA contents in the serum were significantly decreased and the content of estradiol significantly increased after MCZ exposure. Histological observation showed that the ovarian structure of mice exposed to MCZ was damaged, and the apoptosis was increased. Immunohistochemistry and RT-qPCR showed that the expression of Bax, caspase-3 and caspase-9 significantly increased in the MCZ- group. Conversely, Bcl-2 expression significantly decreased. Transcriptome sequencing showed that the expression of NADH dehydrogenase ND3, ND4L, ND6 subunits, Cyt b, and SDHC genes in mitochondria were down-regulated after MCZ exposure, similar to real-time PCR analysis. These results collectively indicate that the MCZ can affect the abnormal function of mitochondrial respiratory chain, lead to oxidative phosphorylation decoupling, produce oxidative stress, and finally cause ovarian injury and apoptosis in mice.

The Influence of Wetting Agent and Type of Nozzle on Copper Hydroxide Deposit on Sugar Beet Leaves (Beta vulgaris L.)

Protective fungicides are sensitive to environmental conditions such as rainfall and solar radiation. Therefore, it is important to prolong the biological activity and fungicide resistance to the above-mentioned factors that can be achieved by adding a wetting agent to the working solution. Additionally, the quality and efficiency of preventive contact fungicides significantly depend on the application technique. Thus, it is important to make the right choice of the nozzles and adjust the working parameters of the treatment. The aim of this work is to determine the influence of a wetting agent and type of nozzle on copper hydroxide (2 L ha−2) deposits on sugar beet leaves. Experiments are set up under laboratory and field conditions. A pinole-based wetting agent is applied at three rates (0.3, 0.6, and 1.0 L ha−1) and two types of nozzles are used (standard with flat jet and modern turbo-drop twin-jet). A brilliant blue tracer is added to a working solution to enable the measurement of copper hydroxide deposits. The deposit amount is recorded before and after the rain simulation (15 L m−2) with a spectrophotometer light beam. In order to ensure the timeliness of the application of fungicides, remote sensing of vegetative indices is used as an indicator of disease occurrence. The results indicated an increase in copper hydroxide deposits with the increase in wetting agent rates for both types of nozzles and in both laboratory and field experiments. Moreover, when applying the copper hydroxide mixtures with modern turbo drop nozzles, the increase in copper hydroxide deposit is significant, compared to the standard nozzles.

Effect of Foliar Application of Micronutrients and Fungicides on the Nitrogen Use Efficiency in Winter Wheat

The increase in the grain density (GD) is the key factor for effectively controlling Nitrogen-Use Efficiency (NUE) in winter wheat. Winter-wheat protection with fungicides and/or foliar fertilization with micronutrients during the critical stages of yield formation affects the grain yield by increasing GD. This hypothesis was verified in a two-factor field experiment, carried out in the 2013/2014, 2014/2015, 2015/2016 growing seasons. A field experiment in a two-factor split-plot design, included three systems of wheat foliar protection (FP): (i) N + Mi (N + macronutrients), (ii) N + P (N + fungicides), (iii) N + Mi + P, and 0, 40, 80, 120, 160, 200, 240 kg N ha−1. The grain yield, despite the significant effect of years, depended on the interaction of FP and N doses. The maximum yield of 8.1, 10.7, 11.1 t ha−1 for the optimal N dose of 79.8, 227.4, and 245.2 kg ha−1, was achieved, respectively, for N + Mi, N + N, N + Mi + P. The wheat-grain yield depended significantly on GD (R2 = 0.98, p ≤ 0.001). Wheat protected with fungicides increased GD gradually with the N dose, reaching over 3000 grains per m2 when fertilized with 200 kg N ha−1. The lack of fungicide protection, reducing GD, consequently resulted in a greater accumulation of N in straw at the expense of grain. Fungicide protection of wheat through the positive effect on N management by wheat should be considered as an agronomic measure that supports N-Use Efficiency.

A fractional mathematical modeling of protectant and curative fungicide application

Fungicides are consumed to foreclose or slow the epidemics of disease germ by fungi. Crop cultivation is a favorable business platform for farmers, but it is also very common for them to have losses. These losses happen by attacking pathogens, such as fungi, oomycetes (water fungi), viruses, bacteria, nematodes, and viroid that spread the infection into the plants. In this article, we derive a fractional mathematical model for simulating the dynamics of fungicide application via Caputo-Fabrizio fractional derivative. Caputo-Fabrizio operator is defined with non-singular type kernel which is better than singular kernel. We give some important proofs related to the existence of a unique solution of the given model. We derive the solution of the model by using the Adams-Bashforth algorithm and also mentioned the stability of the method. We plotted the number of graphs at different fungicide application rate, fungicide decay rate, fungicide effectiveness, curatives rate of fungicide, growth rate of the host, and removal rate. A complete structure of the given problem can be understood by this paper. The main novelty of this work is to understand the role of fungicide application in the disease caused by fungi with the help of fractional derivatives consisting memory effects.

Efficacy of fungicides in protection of rice crops from Magnaporthe oryzae B. Couch

Efficacy of fungicides in protection of rice crops from Magnaporthe oryzae B. Couch

Biological and chemical pruning wound protectants reduce infection of grapevine trunk disease pathogens

Grapevine trunk diseases (GTDs) are currently considered some of the most important challenges for viticulture, curtailing vineyard longevity and productivity in nearly every raisin, table and wine grape production region in California and worldwide. Pruning wounds provide the main entry point for fungal pathogens responsible for these diseases; pathogens enter the wounds following precipitation events. The aim of this study was to evaluate the efficacy of selected chemical and experimental biological fungicides for protection of pruning wounds against two of the most common and virulent fungal pathogens causing GTDs:Eutypa lataandNeofusicoccum parvum. This study was conducted on sauvignon blanc at the UC Davis Department of Plant Pathology Field Station. Results showed that several chemical and biological fungicides, notably the chemical fungicide Luna Sensation, the biofungicide Vintec and a combination of the biofungicides Bio-Tam and CrabLife Powder, provided significant protection against at least one of the two canker pathogens used in this study. However, the majority of products tested did not provide simultaneous control of bothE. lataandN. parvumpathogens, highlighting the continuing challenge of controlling GTDs.

Hematopoietic stem cell and immunotoxicity in zebrafish embryos induced by exposure to Metalaxyl-M

Metalaxyl-M (MM), a protective and therapeutic fungicide, has been shown to be a promising candidate, but its toxicity toward aquatic organisms is unknown. In this study, we evaluated for the first time the immunotoxicity of MM in zebrafish embryos. Phenotypes (heart rate, body length, and yolk area) and the number of neutrophils, macrophages, and T cells in the thymus were analyzed in zebrafish embryo after exposure to MM. Our results showed that zebrafish embryos exposed to MM showed a concentration-dependent increase in the yolk area and a significant decrease in the number of neutrophils, macrophages, and thymus T cells. We detected upregulated expression of related immune signaling genes, such as tnfa, nfkb3, cxcl-c1c, il6, mmp9, and tgfb1. Additionally, we observed a significant decrease in HSCs in zebrafish larvae after exposure to MM. IWR-1 could restore the number of neutrophils and macrophages after exposure to MM. The results indicated that MM exerted developmental toxicity and immunotoxicity to zebrafish embryos, and these phenomena may be caused by MM's regulation of WNT signaling pathway.

Optimizing the Integration of a Biopesticide (Bacillus subtilis QST 713) with a Single-Site Fungicide (Benzovindiflupyr) to Reduce Reliance on Synthetic Multisite Fungicides (Captan and Mancozeb) for Management of Apple Scab.

Apple scab is one of the most economically important diseases of apple in temperate production regions. In the absence of durable host resistance in commercially preferred cultivars, considerable applications of fungicides are needed to manage this disease. With the sequential development of resistance to nearly all classes of single-site fungicides in the apple scab pathogen Venturia inaequalis, synthetic multisite fungicides, such as mancozeb and captan, often comprise the core of chemical management programs for apple scab. Although these fungicides have demonstrable benefits for both disease and fungicide resistance management, the sustainability movement within agriculture aims to reduce reliance on such fungicides because of their broader environmental impacts. In this study, we establish a framework to enhance the feasibility of chemical management programs that do not rely on use of synthetic multisite protectant fungicides to manage apple scab. Specifically, we wish to evaluate chemical programs that integrate the biopesticide Bacillus subtilis QST 713 (Serenade Opti) in rotation with benzovindiflupyr (Aprovia), a single-site fungicide belonging to the class of succinate dehydrogenase inhibitors (SDHI), to circumvent the need for applications of synthetic multisite fungicides. During implementation of these programs, disease incidence data were taken at biweekly intervals. Regardless of the seasonal challenges presented in the 2 years of this study, when Bacillus subtilis QST 713 was used in place of captan and mancozeb mixtures, we did not observe any significant differences (P > 0.05) in development of apple scab symptoms between any of the management programs for the vertical axis or super spindle orchards in either year. This potential for substituting synthetic multisite fungicides with biopesticides is best realized when the programs are used with a decision support system in a super spindle planting system, where trees have reduced canopy densities. This 2-year study shows the potential to achieve adequate disease control using the integration of SDHI fungicides and biological controls without the use of synthetic multisite fungicides.

Genetic Diversity and Azole Resistance Among Natural Aspergillus fumigatus Populations in Yunnan, China.

The emergence and spread of azole resistance alleles in clinical and environmental isolates of Aspergillus fumigatus is a global human health concern and endangers the "One Health" approach in our fight against antifungal resistance (AFR) in this pathogen. A major challenge to combat AFR in A. fumigatus is the massive aerial dispersal ability of its asexual spores. Our recent fine-scale survey of greenhouse populations of A. fumigatus near Kunming, Yunnan, China, suggested that the use of azole fungicides for plant protection was likely a major driver of the high-frequency azole-resistant A. fumigatus (ARAF) in greenhouses. Here, we investigated the potential spread of those ARAF and the structure of geographic populations of A. fumigatus by analyzing 452 isolates from 19 geographic locations across Yunnan. We found lower frequencies of ARAF in these outdoor populations than those in greenhouses near Kunming, but there were abundant new alleles and new genotypes, including those associated with azole resistance, consistent with multiple independent origins of ARAF across Yunnan. Interestingly, among the four ecological niches, the sediments of a large lake near Kunming were found to have the highest frequency of ARAF (~ 43%). While most genetic variations were observed within the 19 local populations, statistically significant genetic differentiations were found between many subpopulations within Yunnan. Furthermore, similar to greenhouse populations, these outdoor populations of A. fumigatus in Yunnan were significantly different from those in other parts of the world. Our results call for increased attention to local and regional studies of this fungal pathogen to help develop targeted control strategies against ARAF.

Application of plant-derived bioactive compounds as seed treatments to manage the rice pathogen Fusarium fujikuroi

Plant essential oils (EO) possess antifungal properties due to the presence of terpenoids and phenolics capable of damaging microbial cell membranes. The compounds present in EO could represent a valid alternative to synthetic fungicides in rice crop protection, especially in Europe, where the available plant protection products are increasingly scarce, particularly for managing seed-borne fungal pathogens like Fusarium fujikuroi Nirenberg, the causal agent of bakanae disease. Bakanae is a major concern in Europe for seed producers, which often fail to comply with the strict regulatory limits on the presence of the pathogen in the field, resulting in the rejection of the seed crop from marketing and economic losses. The present work was aimed at studying 1) the in vitro effect of EO derived compounds against F. fujikuroi and 2) their efficacy in disease management under field conditions applied as seed treatments. Results confirmed the in vitro antifungal activity of tested compounds: specifically, thymol (0.025% vol/vol), terpinen-4-ol (0.1%), and eugenol (0.05%) showed strong antifungal activity against all the tested F. fujikuroi strains. Two-years, two-locations open field trials showed that seeds treated with thymol (20%) and eugenol (5%) significantly reduced bakanae incidence compared to untreated control, without any phytotoxicity effect on rice seed. The efficacy of these two compounds in managing the disease without affecting germination rates was comparable to the commercially available prochloraz and triticonazole formulation, considered as the positive control. Our results suggest that thymol and eugenol could be used as alternative fungicides in innovative formulations for seed dressing, with the advantage of being compliant with the European IPM framework and organic farming legislation.

Fungal pathogens of mango (Mangifera indica L.) inflorescences

This is the first comprehensive study to identify fungal pathogens of mango (Mangifera indica L.) inflorescences in Puerto Rico. A total of 452 mango inflorescences were collected from four cultivars at seven developmental stages during two blooming seasons. Samples were gathered from the germplasm collection at the Agricultural Experiment Station of the University of Puerto Rico in Juana Díaz, Puerto Rico. Eight different symptoms were observed: cankers, flower abortion, powdery mildew, rachis necrotic lesions, rachis soft rot, tip blight, vascular wilt, and insect perforations with necrotic borders. Necrosis was the most prevalent symptom (47%), followed by powdery mildew (19%) and tip blight (6%). Symptoms of malformation were never observed in the field. Using a modified Horsfall and Barratt scale, data on all mango cultivars pooled from two blooming seasons showed that the full bloom stage, the last inflorescence developmental stage (G), displayed the highest mean disease severity (42.67%). This severity value was significantly higher than those of the other developmental stages evaluated (P<0.05). Early inflorescence developmental stages were asymptomatic or showed the lowest percentage of disease severity. An ANOVA was performed to compare disease severity among all mango cultivars regardless of developmental stage. Results showed that there were significant differences (P<0.05) between mean disease severity of cultivars ‘Parvin’ and ‘Haden’. Mean disease severity was higher in ‘Haden’ (20%) when compared to ‘Parvin’ (10.7%). There were no statistical differences in mean disease severity between cultivars ‘Irwin’, ‘Keitt’ and ‘Parvin’, or between ‘Irwin’, ‘Haden’ and ‘Keitt’. In addition to the powdery mildew caused by Pseudoidium anacardii, 26 genera of fungi, mainly of Ascomycetes, were identified from a total of 569 fungal isolates, from symptomatic and asymptomatic inflorescences. The most common fungi were: Diaporthe spp. (29%), followed by members of the Botryosphaeriaceae (16%), Curvularia spp. (11%) and Fusarium spp. (11%). Many fungal pathogens identified in this study were isolated from asymptomatic tissue, occurring as endophytes or latent pathogens: A. alternata, various members of the Botryosphaeriaceae, C. gloeosporioides complex, Cladosporium spp. and F. decemcellulare. Thus, the use of protectant fungicides will not be as effective as systemics in their control. Correct identification of fungal pathogens affecting mango inflorescences is important when quarantine regulations are applied. In addition, this information will facilitate the development of better management strategies in mango orchards.

Fungicide management in the Asian soybean rust

Asian soybean rust is the major crop disease and the management of the use of the fungicide is important for effective control. The objective of this work was to evaluate the management of fungicides with sequential applications to control Asian soybean rust. The experimental design used was a randomized block with four replications and eight treatments with different combinations of fungicides from the following chemical groups: triazole, strobilurin, carboxamide, and dithiocarbamate. The applications were carried out with backpack spray equipment at constant pressure (CO2) and a spray rate of 200 L ha-1. The severity of rust, the area under the disease progress curve, control efficiency, mass of 1,000 grains, and productivity were evaluated. The protective fungicide mancozeb, in mixtures with systemic fungicides, were more effective for the control of Asian soybean rust than the systemic fungicides applied without the protective fungicide.

Ag-Doped and Antibiotic-Loaded Hexagonal Boron Nitride Nanoparticles as Promising Carriers to Fight Different Pathogens.

Utilization of antibacterial components-conjugated nanoparticles (NPs) is emerging as an attractive strategy for combating various pathogens. Herein, we demonstrate that Ag/BN NPs and antibiotic-loaded BN and Ag/BN nanoconjugates are promising carriers to fight bacterial and fungal infections. Extensive biological tests included two types of Gram-positive methicillin-resistant Staphylococcus aureus strains (B8469 and MW2), two types of Gram-negative Pseudomonas aeruginosa strains (ATCC27853 and B1307/17), and 47 types of Escherichia coli strains (including 41 multidrug-resistant ones), as well as five types of fungal cultures: Candida albicans (candidiasis-thrush) ATCC90028 and ATCC24433, Candida parapsilosis ATCC90018, Candida auris CBS109113, and Neurospora crassa wt. We have demonstrated that, even within a single genus Escherichia, there are many hospital E. coli strains with multi-drug resistance to different antibiotics. Gentamicin-loaded BN NPs have high bactericidal activity against S. aureus, P. aeruginosa, and 38 types of the E. coli strains. For the rest of the tested E. coli strains, the Ag nanoparticle-containing nanohybrids have shown superior bactericidal efficiency. The Ag/BN nanohybrids and amphotericin B-loaded BN and Ag/BN NPs also reveal high fungicidal activity against C. albicans, C. auris, C. parapsilosis, and N. crassa cells. In addition, based on the density functional theory calculations, the nature of antibiotic-nanoparticle interaction, the sorption capacity of the BN and Ag/BN nanohybrids for gentamicin and amphotericin B, and the most energetically favorable positions of the drug molecules relative to the carrier surface, which lead to lowest binding energies, have been determined. The obtained results clearly show high therapeutic potential of the antibiotic-loaded Ag/BN nanocarriers providing a broad bactericidal and fungicidal protection against all of the studied pathogens.

NaSCN–(NH4)2Ce(NO3)6 system in heterocycle thiocyanation: synthesis of novel highly potent broad-spectrum fungicides for crop protection

NaSCN–(NH4)2Ce(NO3)6 system in heterocycle thiocyanation: synthesis of novel highly potent broad-spectrum fungicides for crop protection

Exogenous application of salicylic acid to control coffee rust

The exogenous application of salicylic acid can induce plant resistance against pathogens. However, little is known about the potential uses of this bioregulator for controlling coffee diseases. In this study, we assessed the effect of applying salicylic acid (SA – 150 mg L-1) on the management of coffee rust (Hemileia vastatrix) in a 7-year-old coffee plantation with low crop load (651.6 kg ha-1 in 2017). For comparison, plants were sprayed with protectant fungicide (copper hydroxide – CH) and standard fungicides (SF) used by local farmers (boscalid, pyraclostrobin + epoxiconazole, and copper hydroxide). Non-treated plants were included as a negative control. Five monthly applications were performed from November 2016 to March 2017. Rust incidence and severity, defoliation, and growth of plagiotropic branches were evaluated monthly. The activity of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and total proteins was assessed one day after the first, third, and fifth product applications. Compared to untreated plants, SA reduced the severity and incidence of rust from 36.3 to 54.7%, while CH and SF reduced disease from 31.8 to 54.6% and from 83.8 to 88%, respectively. SA reduced defoliation by 54.1%. SA increased the concentration of CAT, APX, and SOD after the first application. However, this effect was not observed after subsequent applications. Foliar application of SA reduces the severity and incidence of coffee rust and defoliation in plants with a low crop load.

Épocas de aplicação de azoxistrobina + mancozebe no controle de mancha branca do milho

Um dos principais métodos de controle da mancha branca do milho, o controle químico com estrobilurinas e fungicidas protetores demonstraram efeito no controle da doença, no entanto, condicionada ao momento de sua realização em estádios fenológicos da cultura. O objetivo deste trabalho foi avaliar o controle e efeito no progresso temporal da mancha branca do milho com a associação dos fungicidas mancozebe e azoxistrobina em diferentes épocas de aplicação, dois cultivares, duas localidades de plantio e o efeito na produtividade da cultura. Os experimentos foram conduzidos nos municípios de Marechal Cândido Rondon e Sertanópolis, PR. Foram utilizados dois híbridos suscetíveis, DKB230PRO3 e DKB290PRO3. O delineamento experimental utilizado foi de blocos casualizados com 4 repetições. As avaliações foram efetuadas 10 dias após cada aplicação, além de uma avaliação no estádio de maturidade fisiológica. A severidade da doença foi avaliada através da quantificação da área foliar lesionada em 10 plantas por parcela e utilizadas no cálculo da Área Abaixo da Curva de Progresso da Doença, submetidos a análise de variância e o teste de médias. As curvas de progresso da doença foram ajustadas aos modelos logístico e exponencial. A produtividade foi estimada após a colheita manual, com o peso de mil grãos e produtividade (kg ha-1). Aplicações dos fungicidas em estádios V8 e V4+V8+VT proporcionaram melhor controle da mancha branca. Aplicações no estádio V4 não proporcionaram severidades diferentes da testemunha sem aplicação. Não foram observados ganhos significativos em produtividade em função da aplicação dos fungicidas.

Toxicity effects of procymidone, iprodione and their metabolite of 3,5-dichloroaniline to zebrafish

Dicarboximide fungicides mainly including procymidone, iprodione, vinclozolin, and dimethachlon are often applied as protective fungicides, 3,5-dichloroaniline (3,5-DCA) is their common metabolite in plant and environment. In this study, the acute toxicity of procymidone, iprodione and their metabolite of 3,5-DCA toward zebrafish was evaluated by semi-static method. The enrichment and metabolism of procymidone and iprodione in zebrafish were also clarified. The results indicated that procymidone and iprodione exhibited moderately toxic to adult zebrafish with the LC50 of 2.00 mg/L, 5.70 mg/L at 96 h. Both procymidone and iprodione could be metabolized to 3,5-DCA in zebrafish, which showed higher toxic to adult zebrafish with the LC50 of 1.64 mg/L at 96 h. From the perspective of histomorphology, for all treatment groups, the brain of the zebrafish was significantly damaged, while the damage to gut and gills was lighter. For procymidone, the biological concentration factor (BCF8d) were 236 and 246 at the exposure concentration of 0.2 mg/L and 0.04 mg/L, and the BCF8d were 3.2 and 2.4 for iprodione at the exposure concentration of 0.5 mg/L and 0.1 mg/L. Therefore, the procymidone and iprodione were moderate-enriched and low-enriched in zebrafish, respectively.

Difenoconazole-based fungicides for orchard protection

A comparative assessment of the effectiveness of 4 difenoconazole-based fungicides in the fight against apple scab in the Krasnodar region and the Rostov Region for several years has been carried out. The preparations Sercadis Plus, SC were applicated at a rate of application of 1.2 l/ha; Embrelia, SC – 1.5 l/ha; Cidely Top, DС – 0.7 l/ha and Tersel, WG – 2.5 kg/ha three times, against different infectious backgrounds, starting with the “pink bud” phenophase (the end of flowering stage). The following apple cultivars were used: Idared, Champion and Golden Delicious. Research has shown that all studied fungicides significantly reduced the scab infestation of apple leaves and fruits. This resulted in obtaining additional yield in the range of 12.6-46.0%. The fruit grade was high after the treatments: 93.0-100% in the Krasnodar region and 81.5-91.5% in the Rostov Region, while in the nil treatment the percentages of standard products were 68.5% and 44.6%, respectively. According to the toxic load indicator, difenoconazole-based fungicides, such as Embrelia, SC (11.6 LD50 per hectare), were less dangerous for the fruit cenosis.