Effect Of Fungicide Treatment Research Articles

Using Ground and UAV Vegetation Indexes for the Selection of Fungal-Resistant Bread Wheat Varieties

The productivity of wheat in the Mediterranean region is under threat due to climate-change-related environmental factors, including fungal diseases that can negatively impact wheat yield and quality. Wheat phenotyping tools utilizing affordable, high-throughput plant phenotyping (HTPP) techniques, such as aerial and ground RGB images and quick canopy and leaf sensors, can aid in assessing crop status and selecting tolerant wheat varieties. This study focused on the impact of fungal diseases on wheat productivity in the Mediterranean region, considering the need for a precise selection of tolerant wheat varieties. This research examined the use of affordable HTPP methods, including imaging and active multispectral sensors, to aid in crop management for improved wheat health and to support commercial field phenotyping programs. This study evaluated 40 advanced lines of bread wheat (Triticum aestivum L.) at five locations across northern Spain, comparing fungicide-treated and untreated blocks under fungal disease pressure (Septoria, brown rust, and stripe rust observed). Measurements of leaf-level pigments and canopy vegetation indexes were taken using portable sensors, field cameras, and imaging sensors mounted on unmanned aerial vehicles (UAVs). Significant differences were observed in Dualex flavonoids and the nitrogen balance index (NBI) between treatments in some locations (p < 0.001 between Elorz and Ejea). Measurements of canopy vigor and color at the plot level showed significant differences between treatments at all sites, highlighting indexes such as the green area (GA), crop senescence index (CSI), and triangular greenness index (TGI) in assessing the effects of fungicide treatments on different wheat cultivars. RGB vegetation indexes from the ground and UAV were highly correlated (r = 0.817 and r = 0.810 for TGI and NGRDI). However, the Greenseeker NDVI sensor was found to be more effective in estimating grain yield and protein content (R2 = 0.61–0.7 and R2 = 0.45–0.55, respectively) compared to the aerial AgroCam GEO NDVI (R2 = 0.25–0.35 and R2 = 0.12–0.21, respectively). We suggest as a practical consideration the use of the GreenSeeker NDVI as more user-friendly and less affected by external environmental factors. This study emphasized the throughput benefits of RGB UAV HTPPs with the high similarity between ground and aerial results and highlighted the potential for HTPPs in supporting the selection of fungal-disease-resistant bread wheat varieties.

Effect of Fungicide Treatment on Multi-Mycotoxin Occurrence in French Wheat during a 4-Year Period

Wheat represents one of the most widely consumed cereals worldwide. Cultivated in winter and spring, it is vulnerable to an array of different pathogens, including fungi, which are managed largely through the in-field application of fungicides. During this study, a 4-year field investigation (2018–2021) was performed in France, aiming to assess the efficacy of fungicide treatment to reduce mycotoxin contamination in common and durum wheat. Several different commercially available fungicides were applied via sprayers. Concentrations of mycotoxins and fungal metabolites in wheat were determined using a multi-analyte liquid-chromatography–tandem-mass-spectrometry-based method. The highest contamination levels and strongest effects of fungicides were observed in 2018, followed by 2021. A significant fungicide-mediated reduction was observed for the trichothecenes deoxynivalenol, deoxynivalenol-3-glucoside, nivalenol, and nivalenol-3-glucoside. Furthermore, fungicide treatment also reduced levels of culmorin and its hydroxy metabolites 5- and 15-hydroxy-culmorin, as well as aurofusarin. Interestingly, the Alternaria metabolite infectopyron was increased following fungicide treatment. In conclusion, fungicide treatment was effective in reducing mycotoxin levels in wheat. However, as complete prevention of mycotoxin contamination was not achieved, fungicide treatment should always be combined with other pre- and post-harvest mycotoxin mitigation strategies to improve food and feed safety.

Effect of fungicide treatment and nitrogen fertilisation on the yield of two breeding types of winter oilseed rape cultivars

The effect of three fungicide treatment programmes and the level of spring nitrogen fertilisation on the seed yield of two types ofcultivars of Brassica napus L. sown at two different seeding rates was studied in a field experiment. The subject of the study was anopen-pollinated cultivar ‘Casoar’ and a restored hybrid cultivar ‘Visby’. Three plant protection programmes, two levels of spring nitrogenfertilisation (160 and 220 kg N⋅ha1), and two different seeding rates for each cultivar (‘Visby’—50 and 70 seeds⋅⋅m2; ‘Casoar’—60 and 80 seeds⋅m2) were included. The most intensive protection programme comprised three fungicide treatments: first in autumn at the six-leaves-unfolded stage—BBCH 16, second in spring at the stem elongation stage—BBCH 33, and third at the full flowering stage—BBCH 65. One of two less intensive programmes of plant protection included fungicide application in autumn at the sixleaves-unfolded stage—BBCH 16 and at the full flowering stage—BBCH 65, while the second included fungicide application in spring at the stem elongation stage—BBCH 33 and at the full flowering stage—BBCH 65. The effectiveness of the protection programmes and nitrogen fertilisation was influenced by the intensity of abiotic stress factors. The average yield from the plots protected against pathogens was significantly higher than that from the untreated plots. The increase of nitrogen fertilisation from 160 to 220 kg⋅ha1 also caused a significant increase of average seed yield. The yield of cultivar ‘Visby’ was higher and less dependent on the seeding rate compared to cultivar ‘Casoar’.Keywords: Winter oilseed rape; Cultivars; Disease control; Nitrogen fertilisation; Seeding rate; Sclerotinia sclerotiorum; Leptosphaeria spp.; Alternaria spp. Botrytis cinerea.

Effect of Protective Coatings on Wooden Elements Exposed to a Small Ignition Initiator

This paper presents the results of monitoring the behaviour of selected wood species exposed to a small ignition initiator. We specifically aimed to investigate the effect of retardant coating on the combustion process of the wood species spruce (Picea abies), red spruce (Larix decidua), Scots pine (Pinus sylvestris), ash (Fraxinus excelsior L.), beech (Fagus sylvatica), and oak (Quercus robur) when exposed to a small initiator of ignition. At the same time, we studied the effect of different types of fungicidal agents (based on N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine; alkyl (C12–16) dimethylbenzyl ammonium chloride or 3-iodo-prop-2-inylbutylcarbamate) on the effectiveness of a flame retardant (containing ferric phosphate) applied to the selected fungicide-treated wood samples. The experimentally obtained mass-loss and flame-spread results were statistically evaluated using the QtiPlot software program. A significant dependence of mass loss and surface flame spread on wood species was the primary focus. It was only confirmed for the surface-flame-spread variable. The dependence of the effect of fungicide treatment on the effectiveness of the selected retardant was confirmed. Fungicidal coatings with the active ingredient alkyl/benzyl (C12–16) dimethylbenzyl ammonium chloride indicated the lowest mass loss rate and flame spread for all wood samples.

Disentangling the Factors Affecting the Dynamic of Pseudocercospora fijiensis: Quantification of Weather, Fungicide, and Landscape Effects.

Quantifying the effect of landscape composition on disease dynamics remains challenging because it depends on many factors. In this study, we used a hybrid process-based/statistical modeling approach to separate the effect of the landscape composition on the epidemiology of banana leaf streak disease (BLSD) from weather and fungicide effects. We parameterized our model with a 5-year dataset, including weekly measures of BLSD on 83 plots in Martinique. After estimating the intrinsic growth parameters of the stage evolution of the disease (SED), we evaluated the dynamic effect of five fungicides. Then, we added the intra- and inter-annual effect on disease dynamics using a generalized linear model. Finally, the whole model was used to assess the annual effect of the landscape on the SED for 11 plots. We evaluated the significance of the landscape composition (proportions of landscape elements in 200-, 500-, 800-, 1,000-m-radius buffer zones) on the landscape effect evaluated with the model. The percentage of hedgerows in a 200-m-radius buffer zone was negatively correlated to the landscape effect, i.e., it acted as a constraint against BLSD spreading and development. The proportion of managed-banana-plants in a 1,000-m-radius buffer zone was negatively correlated to the landscape effect, probably due to a mass effect of fungicide treatments. Inversely, the proportions of forest and the proportion of unmanaged-banana-plants, both in 1,000-m-radius buffer zones, were positively correlated with the landscape effect. Our study provides a holistic approach of the role biotic and abiotic factors play on the dynamics of BLSD.

Non-Invasive Evaluation of Different Soil Tillage and Seed Treatment Effects on the Microbial Originating Physiological Reactions of Developing Juvenile Maize.

The successful production of maize is fundamentally determined by a good choice of tillage type. Options include conventional tillage based on soil rotation, as well as a more recent conservation approach. Our aims were to determine the stress physiological effects of the plant remains left behind by different tillage procedures on the juvenile maize plants, combined with the effects of fungicide treatment on the seeds. These effects were followed and investigated by means of biophoton emission measurement, an in vivo and non-invasive imaging technique, along with chlorophyll content estimation, as well as microbial- and polymerase chain reaction-based identification of fungi presence. Our results confirmed the response reactions of maize triggered by a soil covering plant remains on the initial development and physiological involvement of maize. The positive effects of seed treatment on initial development are manifested only at the final stage of the experiment. The fungal microbiological analysis confirmed the dominant presence of necrotrophic parasites on plant residues, the stress-inducing properties of which were possible to monitor by biophoton emission. Furthermore, the presence of Fusarium spp. was confirmed by PCR analysis from samples treated with plant residues.

Effects of fungicide treatment on metabolite profiles of Aquilariamalaccensis

Aquilaria malaccensis is an agarwood-producing tree. Previous studies have shown that endophytic fungi may colonize A. malaccensis. Endophytes are known to be capable of altering plants' secondary metabolites, although the mechanism adopted by the plants remains unclear. This paper aimed to observe the differences in the metabolite profiles of A. malaccensis by eliminating the presence of endophytic fungi with fungicide. Three solvents i.e., ethanol, ethyl acetate, and chloroform, were used for extracting the 2-year-old A. malaccensis. The extracts were examined by scanning with UV–Vis Spectrophotometry and Gas Chromatography-Mass Spectrometry (GC-MS) for the metabolites profile. The absorbances data were analyzed using Principal Component Analysis (PCA), followed by Partial Least Squares-Discriminant Analysis (PLS-DA). The results showed that groupings between control and fungicide-treated extract formed in the PLS-DA score plot. The important wavelength values for the separation were identified. Identification of compounds found inside the A. malaccensis plants based on the GC-MS results was conducted. Several compounds were specifically found in the control-treated extract of A. malaccensis plants. Respectively, the total phenolics and total flavonoids inside the A. malaccensis extract were calculated using Folin-Ciocalteu's and aluminum chloride tests. A decrease in phenolic and flavonoid content was observed mostly in the roots. These findings are fundamental to understanding endophytes' ability to alter the secondary metabolites produced in A. malaccensis.

Influence of Agaricus bisporus establishment and fungicidal treatments on casing soil metataxonomy during mushroom cultivation

The cultivation of edible mushroom is an emerging sector with a potential yet to be discovered. Unlike plants, it is a less developed agriculture where many studies are lacking to optimize the cultivation. In this work we have employed high-throughput techniques by next generation sequencing to screen the microbial structure of casing soil employed in mushroom cultivation (Agaricus bisporus) while sequencing V3-V4 of the 16S rRNA gene for bacteria and the ITS2 region of rRNA for. In addition, the microbiota dynamics and evolution (bacterial and fungal communities) in peat-based casing along the process of incubation of A. bisporus have been studied, while comparing the effect of fungicide treatment (chlorothalonil and metrafenone). Statistically significant changes in populations of bacteria and fungi were observed. Microbial composition differed significantly based on incubation day, changing radically from the original communities in the raw material to a specific microbial composition driven by the A. bisporus mycelium growth. Chlorothalonil treatment seems to delay casing colonization by A. bisporus. Proteobacteria and Bacteroidota appeared as the most dominant bacterial phyla. We observed a great change in the structure of the bacteria populations between day 0 and the following days. Fungi populations changed more gradually, with A. bisporus displacing the rest of the species as the cultivation cycle progresses. A better understanding of the microbial communities in the casing will hopefully allow us to increase the biological efficiency of the crop.

Temporal Dynamics and Severity of Cucurbit Downy Mildew Epidemics as Affected by Chemical Control and Cucurbit Host Type.

Cucurbit downy mildew caused by the oomycete Pseudoperonospora cubensis is an important disease that affects members of Cucurbitaceae family globally. However, temporal dynamics of the disease have not been characterized at the field scale to understand how control strategies influence disease epidemics. Disease severity was assessed visually on cucumber and summer squash treated with weekly alternation of chlorothalonil with cymoxanil, fluopicolide, or propamocarb during the 2018 spring season and 2019 and 2020 fall seasons in North Carolina and the 2018 and 2020 fall seasons in South Carolina. Disease onset was observed around mid-June during the spring season and early September during the fall season, followed by a rapid increase in severity until mid-July in the spring season and late September or mid-October in the fall season, typical of polycyclic epidemics. The Gompertz, logistic, and monomolecular growth models were fitted to disease severity using linear regression and parameter estimates to compare the effects of fungicide treatment and cucurbit host type on disease progress. The Gompertz and logistic models were more appropriate than the monomolecular model in describing temporal dynamics of cucurbit downy mildew, with the Gompertz model providing the best description for 34 of the 44 epidemics examined. Fungicide treatment and host type significantly (P < 0.0001) affected the standardized area under disease progress curve (sAUDPC), final disease severity (Final DS), and weighted mean absolute rates of disease progress (ρ), with these variables, in most cases, being significantly (P < 0.05) lower in fungicide-treated plots than in untreated control plots. Except in a few cases, sAUDPC, Final DS, and ρ were lower in cases where chlorothalonil was alternated with fluopicolide or propamocarb than in cases where chlorothalonil was alternated with cymoxanil or when chlorothalonil was applied alone. These results characterized the temporal progress of cucurbit downy mildew and provided an improved understanding of the dynamics of the disease at the field level. Parameters of disease progress obtained from this study could serve as inputs in simulation studies to assess the efficacy of fungicide alternation in managing fungicide resistance in this pathosystem.

Comparison of Frequentist and Bayesian Generalized Linear Models for Analyzing the Effects of Fungicide Treatments on the Growth and Mortality of Piper Nigrum

Foot rot disease poses a devastating threat to pepper agriculture. In Vietnam, conventionally, fungicides are the control methods used against the disease. However, the practical effectiveness of fungicide treatment has yet to be quantitatively assessed. To fill this gap a three-factorial experiment was conducted, the factors of which were fungicide application, soil type, and infection pathway, with plant mortality and plant growth as the target variables. Two of the most common fungicides were chosen, including Agrifos 400 (potassium phosphonate) and Aliette 800WG (fosetyl-Al). The two fungicides were used in multiple treatment plans, with soil drenching selected as the means of controlling foot rot disease on red basalt soil and red basalt soil added with organic matter in a greenhouse experiment. Three-month-old pepper (Piper nigrum) plants were treated with Agrifos (application interval of 10 and 20 days), Aliette (application interval of 30 and 60 days), and a combination of both fungicides at half doses. Pepper plants were infected with the fungus Pythium spp. from soil or by direct inoculation. To assess the effect of fungicides on foot rot mortality and the growth of pepper plants, multiple generalized linear models were set up using frequentist and Bayesian approaches. Generally, both procedures suggest the same conclusions for model selection in terms of the Akaike information criterion (AIC) and the deviance information criterion (DIC). Fungicide type was found to be the main factor that affected the survival of plants. Most of the treatments (except Aliette, with an interval of 60 days) effectively reduced the mortality. The usage of fungicides affected the growth of plants in interaction with soil types. Aliette suppressed the growth of plants, especially on red soil, while Agrifos had no effect on the growth of pepper plants. The combined application of Agrifos and Aliette with half doses proves to be a promising solution for balancing cost and effectiveness in protecting plants against foot rot pathogens without affecting their growth. In our case, under the inhomogeneity of variance and unbalanced samples, the Bayesian inference appeared to be the most useful because of its flexibility in terms of model structure.

ВЛИЯНИЕ ФУНГИЦИДНОЙ ОБРАБОТКИ НА УРОЖАЙНОСТЬ И КАЧЕСТВО ЗЕРНА ОЗИМОЙ ПШЕНИЦЫ

In 2017-2019, studies were carried out in the Republic of Tatarstan to study the effect of fungicidal treatment on the yield and grain quality of new varieties of winter wheat. The experiment scheme provided for the study of the following options: variety (factor A) - Darina, Nadezhda, Universiade; fungicidal treatment with Titul Duo at a dose of 0.25 l / ha in the heading phase (factor B), years (factor C). The predecessor is pure steam. The soil in the experiment was gray forest, medium loamy. Content in the arable layer: humus (according to Tyurin) - 3.1-3.4%; pHsal. - 5.2-5.5; K2O (according to Kirsanov) - 122-145 mg / kg of soil, P2O5 (according to Kirsanov) - 262-271 mg / kg of soil. Plot area - 25 m2. The yield and quality of grain largely depend on the phytosanitary state of winter wheat crops, in particular, on the development of diseases. The prevalence and harmfulness of leaf-stem diseases in wheat largely depends on the temperature conditions during the growing season of the crop and on the moisture conditions. As a result of the development of diseases, there is a significant decrease not only in yield, but also a deterioration in the quality characteristics of wheat grain. The highest percentage of prevalence (85%) and intensity of development (45.7%) of powdery mildew was observed in the Universiade variety. Evaluation of plants showed a low lesion of the leaf surface by leaf rust: from 18.6% in the Nadezhda variety to 24.6% in the Universiade variety. The biological effectiveness of protective measures in winter wheat crops when treated with a fungicide has been calculated. On average for varieties for three years, the biological effectiveness of the use of the drug Title Duo was more than 90%. The fungicide treatment increased the yield on average for the studied varieties by 0.55 t / ha. The maximum increase in grain yield was obtained for the Universiade variety - 0.68 t / ha. Indicators of technological quality of grain with an average for varieties increased after treatment with fungicide sowing: weight of 1000 grains per 2.2 grams; grain nature by 5.4 g / l; glassiness by 2.6%; evenness by 1.4%; the wet gluten content is 1.6%. According to the results of analysis of variance, a significant influence of the conditions of the year on the indicators of the technological quality of grain was established: on the nature of the grain (56.8%), the total glassiness of the grain (51.43%), the mass of 1000 grains (51.4%) and the gluten deformation index (52.37%). To a lesser extent, environmental conditions influenced the evenness of the grain (22.0%) and the mass fraction of gluten in the grain (21.66%). At the same time, the contribution of the fungicide to the formation of indicators of the technological quality of grain varied from 7.69% (grain evenness) to 32.43% (gluten content). The grain nature by 14.99% was determined by the fungicidal treatment of crops and only by 10.61% depended on the genotype

Fungicide application and residues in control of Blumeriella jaapii (Rehm) Arx in sweet cherry

To minimize harmful effects of the fungicide application in sweet cherry orchards, it is necessary to use them in accordance with the good agricultural practice and to monitor presence of their residues. Cherry leaf spot caused by Blumeriella jaapii is a significant sweet cherry disease which control is heavily dependent on fungicide treatments. In this study, effects of fungicide treatments against B. jaapii and fungicide residues remaining in sweet cherry fruits after the treatments were evaluated, and the causal agent of cherry leaf spot was confirmed on cherry leaves from untreated control plots using conventional phytopathological techniques (isolation on nutrient media and morphological traits of developed fungal colonies). The trial was set up at two localities in south Serbia (District of Niš), in sweet cherry orchards, according to EPPO methods. Fungicides tested against B. jaapii were based on dodine (650 g a.i./kg) WP formulation, at concentration of 0.1% and mancozeb (800 g a.i./kg) WP formulation, at concentration of 0.25%. During the trial, two evaluations were carried out. Fungicide efficacy was determined according to Abbott. The obtained data were statistically processed by ANOVA and LSD test. In both sweet cherry orchards high efficacy in control B. jaapii was registered in case of dodine application efficacy of 96.3-98.9%, while mancozeb showed slightly lower efficacy of 91.0-95.6%. The results of the dissipation dynamic suggest that the dodine dissipation curves followed the first-order kinetic (Ct=6.23e−0.09, with R2=0.986) and its half-life in sweet cherry fruits was 7.7 days. The final residues in sweet cherry fruits were below the MRL (3 mg/kg) 21 days after the application. The results indicate that sweet cherry fruits can be safely consumed after dodine based fungicides applications at the recommended rate.

Features of basidiomycetous yeasts from grapes and apples associated with crop environment and fermenting juice.

The characterization of grape and apple yeasts was carried out to investigate the ecology of basidiomycetes associated with crop environment and fermenting juice. A total of 15 basidiomycetous strains were analysed for plant-growth promoting properties, sensitivity to fungicides and features related to their survival in fermenting juice (low pH, SO2 and ethanol sensitivity). Only one strain displayed 1-aminocyclopropane-1-carboxylate deaminase activity, whereas other strains were able to produce ammonia and indole-3-acetic acid, solubilize calcium phosphate, and display catalase activity and antagonism against Botrytis cinerea. Strains presented great variability in their sensitivity to fungicides. Rhodotorula mucilaginosa Yl26 and Sporobolomyces agrorum PYCC 8108T displayed low sensitivity to all fungicides, with high tolerance to SO2 and ethanol, and were able to survive in fermenting grape and apple juice. This study revealed the diversity of basidiomycetous yeasts in the important physiological traits that affect their growth, either in the crop environment or in fermenting juice. Identify the possibility of selective effects of fungicide treatments on basidiomycetous yeasts that could offer benefits for grapevines and apple trees, as well as the survival of strains that are better adapted to fermenting juice and that potentially have a role in the aroma of beverages.

Late harvest and chemical treatment of cowpea seeds

Reduced quality ofcowpea due to late harvest and therefore pathogen incidence may influence the results of the germination test, whenever losses are associated with the agentsadhered to seed coat;in that context, chemical treatmentof seeds during the evaluations may reflect more accurately physiological quality of the samples, which in turn may assurethe emergence results of healthy seedlings and establishment of appropriate plant populations inthe field. This study had the objective ofevaluating the effects of fungicide treatment on minimizing physiological quality losses of cowpea seedsdue to lateharvestin germination and seedling development tests. The experimental design was the completely randomized with four replications. Treatments consisted of cowpea, cultivar BRS Guariba, harvested at different times (0, 3, 6, 9, 12 and 15 days after physiological maturity)andtreated or not with fungicide carboxim+thiramfor seed quality tests. Seeds were initially characterized by seed moisture and mass. Afterwards, sampleswere evaluated by tests ofgermination percentage, germination first count, seedling length and dry matter. Data was submitted to variance analysisand means were analyzed as a 2x6 factorial. Means from chemical treatment and harvest times were compared by the Tukey test and regression analysis (p≤0.05), respectively, with subsequent unfolding of any significant interactions. Delayed harvest of cowpea seeds sharply reduces germination and vigor; fungicide treatment before performing physiological tests enables to establish thatseed quality losses can bein part caused by pathogen vehiculationonthe seed coat.

Effect of Fungicide Treatment and Box Unit Wrapping in the Storage of Winter Kimchi Cabbage

Effect of Fungicide Treatment and Box Unit Wrapping in the Storage of Winter Kimchi Cabbage

Isolation of azole-resistant Aspergillus fumigatus from imported plant bulbs in Japan and the effect of fungicide treatment.

Increasing numbers of azole-resistant Aspergillus fumigatus (ARAf) in the environment have become a global public health issue. We surveyed tulip bulbs that were imported from the Netherlands and found that 6.3–15.8% of bulbs were contaminated by ARAf with a tandem-repeat mutation in the promoter region of the cyp51A gene. We also showed that fungicide treatment of the tulip bulbs by benomyl or prochloraz effectively reduced the rate of isolation. This is the first report demonstrating a method of eliminating human fungal pathogens from plant bulbs.

Assessing the effect of fungicide treatment on Cocoa black pod disease in Ghana: Insight from mathematical modeling

Black pod disease is caused by fungi of the species Phytophthora palmivora or Phytophthora megakarya. The disease causes darkening of affected areas of cocoa trees and/or fruits and leads to significant reduction in crop yields and decreases lifespan of the plant. This study presents a simple S_1S_2IT-type model with variable population size to assess the impact of fungicide treatment on the dynamics of the black pod disease. We do both theoretical studies and numerical simulations of the model. In particular, we analyze the existence of equilibrium points and their stability, simulate the model using data on reported black pod cases from Ghana. In addition, we perform sensitivity analysis of the basic reproduction number with respect to the model parameters. The results show that the top three parameters that govern the dynamics of the black pod disease are the treatment rate, transmission rate, and planting rate of new trees

Fungicides have complex effects on the wheat phyllosphere mycobiome.

Effects of fungicide treatments on non-target fungi in the phyllosphere are not well known. We studied community composition and dynamics of target (Puccinia striiformis) and non-target fungi in wheat that was heavily infected with yellow rust. Mycobiotas in bulk leaf samples and individual leaves were studied by metabarcoding targeting the internal transcribed spacer-1 (ITS1) region of the ribosomal DNA. The amount of yellow rust in individual samples was quantified by qPCR (quantitative PCR). In addition, septoria tritici blotch (Zymoseptoria tritici), powdery mildew (Blumeria graminis), tan spot (Pyrenophora tritici-repentis), and yellow rust (P. striiformis) were visually evaluated. We showed how fungal communities were affected by three different broad-spectrum fungicides that had been applied at different timings and doses to control Puccinia striiformis. We showed that fungal content was relatively constant even after fungicide treatments. Principal component analysis demonstrated that communities from fungicide-treated plots could be separated from the communities in non-treated plots. We observed effects of fungicide treatments on fungal communities using different dose, timing and products. Some fungi, including the target organism P. striiformis were effectively controlled by most of the fungicide applications whereas some yeasts and also P. tritici-repentis increased after treatments. We demonstrated the feasibility of using metabarcoding as a supplement to visual assessments of fungicide effects on target as well as non-target fungi.

Does chemical control of blind seed disease (Gloeotinia temulenta) affect endophyte transmission in ryegrass seed crops?

Seven fungicides were evaluated in two separate field trials for their control of blind seed disease and effect on endophyte transmission in perennial ryegrass. Six fungicides were assessed with cultivar One50 for their effects on transmission of the endophyte strain AR37. Five fungicides were labelled for the control of blind seed disease (Gloeotinia temulenta), stem rust (Puccinia graminis) and/or crown rust (P. coronata). In the first trial no attempt was made to induce blind seed disease. The second trial induced disease in the perennial ryegrass cultivars Horizon and Grasslands Samson. The effect of six fungicides on the control of blind seed and transmission frequency of AR37 was determined. In trial one, germination was high (88–93%) and the incidence of blind seed disease low (2–8%) across all treatments. There was no effect of fungicide treatment on germination nor did fungicide treatment affect endophyte transmission. However in trial two, disease incidence reached 63 and 76%, in Samson and Horizon, respectively. The majority of fungicide treatments were effective in reducing blind seed disease but this varied with fungicide type and timing of application. No reduction in endophyte transmission frequency was observed in Samson as a result of fungicide application. A low endophyte transmission frequency was observed with Horizon and therefore no conclusions around fungicide application on the vertical endophyte transmission of AR37 within this particular cultivar could be made. Possible reasons for differences in the effectiveness in control of blind seed disease achieved with the fungicides used and timing of application are discussed. These two trials demonstrate that fungicides can be used to control blind seed in ryegrass without a detrimental effect on AR37 endophyte content in seed produced.

Vliv fungicidního ošetření a podmínek skladování na hladiny vybraných mykotoxinů u ječmene

The aim of the study was to determine the effect of fungicidal treatment and storage on the occurrence of mycotoxins in barley (Hordeum vulgare L.). Barley was initially inoculated with Fusarium culmorum followed by the application of fungicides (prothioconazole and bixafen). A screening of 57 mycotoxins were performed using ultra-performance liquid chromatography in tandem with mass spectrometry. The fungicide treatment affected (P <0.05) the levels of zearalenone, β-zearalenol, arternariol and alternariol-methylether that were present. Levels of deoxynivalenol was highest in the second year of monitoring. 3-acetyl-deoxynivalenol was not affected by fungicidal treatment or storage. The significant increase (P <0.05) of DON-3-glucoside, 15-acetyl-DON, enniatin A, enniatin A1, enniatin B, and enniatin B1 was measured in barley samples. The results of the experiment determined that the use of fungicides can suppress some kinds of mycotoxins, but not others.