FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Estudou-se a sensibilidade do mamoeiro (Carica papaya L.) a fungicidas, com o objetivo de identificar aqueles inÃcuos à planta, visando selecionar produtos quÃmicos que possam ser utilizados no controle das doenÃas fÃngicas da cultura. Neste sentido, foi conduzido um experimento, em condiÃÃes de ripado, no setor hortÃcola do Centro de CiÃncias AgrÃrias da Universidade Federal do CearÃ, em Fortaleza, Estado do CearÃ, Brasil, no perÃodo de abril a julho de 1995. Utilizou-se um delineamento inteiramente casualizado, disposto no esquema fatorial 2 x 10 - cultivares x fungicidas -, com trÃs repetiÃÃes. Os tratamentos foram constituÃdos por nove diferentes compostos quÃmicos - oito fungicidas comerciais e a manipueira (extrato lÃquido das raÃzes de mandioca, Manihot esculenta -, e a testemunha (pulverizaÃÃes com Ãgua). Estes tratamentos foram aplicados, mediante quatro pulverizaÃÃes a intervalos semanais, sobre mudas envasadas de dois cultivares de mamoeiro: Formosa e HavaÃ, compondo os fatoriais. Analisaram-se os efeitos fitotÃxicos dos produtos testados, dez dias apÃs a Ãltima aplicaÃÃo, em funÃÃo da altura da planta, diÃmetro do caule, nÃmero de folhas e sintomas necro-fitotÃxicos foliares. Dentre os fungicidas testados, tebuconazole prevaleceu como fitotÃxico para o mamoeiro, particularmente ao cv Formosa e relativamente à reduÃÃo do numero de folhas. O cultivar HavaÃ, em confronto com o cv. Formosa, mostrou-se bem mais tolerante aos fungicidas testados. / Sensibi1ity studies of the papaya (Carica papaya L.) to various fungicides were developed to select those with high degree of safety to control fungal diseases of the culture. The investigation was carried out on the Horticultural Sector of the Agrarian Science Center of the Federal University of Cearà in a ca., half-shaded shelter, in Fortaleza, State of CearÃ, Brazil, from April to July, 1995. A completely randomized design was arranged in a 2 x 3 x 10 factorial experiment to assess plant reactions lo the fungicides. Treatments were made up of eight commercial fungicides and âmanipueiraâ (a liquid extract from cassava roots, Manihot esculenta) plus the control which was sprayed with tap water. Potted seedlings of two papaya cultivars, v.g., Formosa and Hawaii were sprayed four times at a 7-days interval. Phytotoxicity of the compounds was thoroughly checked by evaluating the following parameters, ten days alter the last spraying: plant height, plant trunk diameter, leaf number and presence of foliar necrotic symptoms. Tebuconazole was phytotoxic to papaya specially to cv. Formosa. This cultivar has also experienced a leaf number reduction. Hawaii cultivar was much more tolerant to the fungicides than the Formosa one.

O controle químico é uma das medidas mais empregadas no manejo de doenças de plantas, sendo imprescindível em inúmeros patossistemas agrícolas. Portanto, compreender a dinâmica das interações entre os produtos e a planta tem grande importância prática, pois poderá embasar ajustes nas estratégias de controle. O trabalho teve por objetivo estudar a tenacidade e a sistemicidade dos fungicidas epoxiconazol, piraclostrobina e fluxapiroxade em plantas de soja e videira. Para avaliar a tenacidade dos produtos foram simuladas chuvas de diferentes intensidades e intervalos após a aplicação. Procedeu-se a inoculação dos patógenos, Phakopsora pachyrhizi e Phakopsora euvitis, e avaliou-se a severidade e a área abaixo da curva de progresso das doenças. Para os estudos de absorção e translocação, utilizaram-se as moléculas radiomarcadas, 14C-epoxiconazol, 14C-piraclostrobina e 14C-fluxapiroxade, que foram diluídas com suas respectivas formulações comerciais. As variáveis foram avaliadas as 3, 9, 24, 48 e 72 horas após a aplicação (HAA). Especificamente para o fungicida fluxapiroxade foram avaliados os efeitos de sua associação ao adjuvante óleo mineral e ao fosfito de potássio em plantas de soja, e sua absorção e translocação em folhas novas e velhas de videira. Em geral, a eficiência dos fungicidas foi crescente com o aumento do intervalo entre a aplicação e a simulação da chuva. A adição do adjuvante aumentou a tenacidade do fluxapiroxade e o fosfito de potássio não teve o mesmo efeito. A sistemicidade na soja foi alta para o epoxiconazol, intermediária para o fluxapiroxade e baixa para a piraclostrobina. Na videira a piraclostrobina foi a mais absorvida, seguida pelo epoxiconazol e o fluxapiroxade. Os fungicidas epoxiconazol e fluxapiroxade translocaram-se predominantemente no sentido acropetal e a piraclostrobina não apresentou translocação a longas distâncias. A adição de adjuvante ao fluxapiroxade promoveu maior e mais rápida absorção e translocação nas plantas de soja, enquanto que, o fosfito de potássio teve efeito antagônico, que resultou em 53% de redução na absorção. Não houve diferença na absorção e translocação do fluxapiroxade em folhas velhas e novas de videira, porém a redistribuição foi maior nas folhas novas. O fluxapiroxade mostrou-se ser um fungicida com potencial protetor e curativo. Protetor, pois grande quantidade do produto (>65%) permanece na parte externa das folhas da soja e videira até as 72 HAA, e curativo pois mostrou uma absorção crescente com o tempo, o que significa que há uma liberação contínua do produto para o interior das folhas. Os folíolos de soja absorveram mais os três fungicidas do que as folhas de videira. A translocação à longa distância em ambas as culturas foi baixa (<1%) para todos os fungicidas avaliados. A translocação do epoxiconazol e fluxapiroxade aumenta com o decorrer das horas nas plantas de soja e não em mudas de videira e a piraclostrobina tem uma translocação limitada e constante em ambas as culturas. Quanto maior e mais rápida for a absorção dos fungicidas, menores serão as perdas decorrentes das intempéries, e por consequência maior será a eficácia dos produtos. / The chemical control is one of the measures most used in the management of plant diseases, being essential in many agricultural pathosystems. Therefore, understanding the dynamics of the interactions between products and plants has great practical importance in providing knowledge that can support better the control strategies. The work has aimed to study the rainfastness and systemicity of the fungicides epoxiconazole, pyraclostrobin and fluxapyroxad in soybean and vine plants. The rainfall was simulated in different intensities and intervals after application in order to assess the rainfastness of the products.The pathogens, Phakopsora pachyrhizi and Phakopsora euvitis were inoculated and the severity and the area under the disease progress curve were assessed. For the uptake and translocation studies, it was used the radiolabeled molecules, 14C-epoxiconazole, 14C-pyraclostrobin and 14C-fluxapyroxad, which were diluted with their respective commercial formulations. The parameters were assessed at 3, 9, 24, 48 and 72 hours after application (HAA). In particular for the fluxapyroxad were assessed the effects of its association with adjuvant and potassium phosphite on soybean plants, and their absorption and translocation in old and new vine leaves. Overall, the fungicides efficiency were boosted with the increasing interval between the application and the rainfall simulation. The addition of adjuvant improved the rainfastness of fluxapyroxad and the phosphite did not have the same effect.The systemicity on soybeans was high for the epoxiconazole, intermediate for fluxapyroxad and low for pyraclostrobin. In vine, pyraclostrobin was more absorbed, followed by epoxiconazole and fluxapyroxad. The fungicides epoxiconazole and fluxapyroxad translocated mainly acropetally and pyraclostrobin did not show translocation to long distances. The addition of adjuvant to fluxapyroxad has promoted greater and more rapid uptake and translocation on soybean plants, while potassium phosphite had antagonistic effect, which resulted in 53% reduction in uptake. There was no difference in the absorption and translocation of fluxapyroxad in old and new vine leaves. Nevertheless, the redistribution was higher in young leaves. The fluxapyroxad proved to be a fungicide with protective and curative potential. Protective because large amount of product (>65%) remains outside of the soy and vine leaves up to 72 HAA and curative because it showed an increased absorption over the time, which means that there is a continuous release of the product into the leaves. The soybean leaflets absorbed more the three fungicides than the vine leaves. The translocation to long distances in both crops were low (<1%) for all evaluated fungicides. The translocation of epoxiconazole and fluxapyroxad increases with the course of time on soybean plants and not in nursery trees of vine and the pyraclostrobin has limited and constant translocation in both crops. In nutshell, as bigger and faster the absorption of fungicides smaller are the losses resulting from the weather and most effective will be the products.

Plant fungal pathogens are a major threat to food security worldwide. The most important method of protecting plants against fungal attack is the use of fungicides, but the development of resistance towards synthetic fungicides is of great concern. Moreover, the health risks associated with the use of chemical fungicides increase the need to search for safe, efficacious and environmentally friendly fungicides. Plants produce antifungal agents by secondary metabolism to protect themselves from fungal attack, and therefore many plant species have substantial antifungal activity. The use of plant extracts could enable the development of inexpensive and environmentally acceptable fungicides based on locally available natural products. This study was undertaken to investigate weedy and invasive plant species for antifungal activity against plant pathogens in order to develop a useful product using a widely available resource. Acetone leaf extracts of seven invasive species (Chromoleana odorata, Ipomoea alba, Tecoma stans, Passiflora suberosa, Passiflora subpeltata, Aristolochia sp, Solanum seaforthianum) were screened against eight plant fungal pathogens viz Rhizoctonia solani, Fusarium oxysporium, Penicillum janthinellum, Penicillum expansum, Aspergillus parasiticus, Aspergillus niger, Pythium ultimum and Phytophthora nicotiana, using microdilution assay and bioautography. The acetone extract of Tecoma stans had reasonable antifungal activity with an average minimal inhibitory concentration (MIC) value against all the fungi of 550 ìg/ml and clear zones on bioautograms indicating inhibition of fungal growth of a compounds with an Rf of 0.082 in BEA against several of the fungal pathogens. Due to the clear compound on bioautography and availability of Tecoma stans, this species was selected for further work. Bioassay-guided fractionation of the leaves of the Tecoma stans dichloromethane (DCM) extract obtained from solvent-solvent fractionation resulted in one major compound, oleanolic acid. The isolated compound had antifungal activity with an average MIC value of 130 ìg/ml against the 10 plant pathogenic fungi and clear bands with an Rf value of 0.082 on bioautograms, indicating fungal growth inhibition. It was surprising that the MIC value of the crude DCM extract was as high as that of the only compound with antifungal activity based on bioautography. These results clearly indicated the possibility of synergisms especially since the average total activity of the extract was nearly 6.5 times higher than that of oleanolic acid with total activity values of 60154 ml for the extract and 9262 ml for oleanolic acid. Cellular cytotoxicity of DCM extract and oleanolic acid was investigated using tetrazoliumbased colorimetric assay (MTT) on Vero monkey kidney cells. The toxicity of the extract and oleanolic acid was determined by LC50 values. The DCM extract and oleanolic acid were toxic with and LC50 of 0.413 mg/ml and 0.129 mg/ml respectively, lower than that of berberine the toxic compound used as control. However therapeutic index which can be defined here as the LC50 in (ìg/ml)/MIC in (ìg/ml), indicated that though the extract and oleanolic acid were toxic, they could be used under controlled conditions against infections of certain of the fungal pathogens. The crude extract had a high therapeutic index value of 21 against microorganisms T. harzianum, R. solani, F. oxysporium and P. expansum; and oleanolic acid had high therapeutic index values of 16 and 64 of against T. harzianum and R.solani respectively. This high therapeutic index value of crude extract and oleanolic acid means that, crude extract and oleanolic acid may be used for treatment of infections by these tested fungi with very little toxicity under controlled conditions. Oleanolic acid had very low antibacterial activity (MIC >250 ìg/ml). against two Grampositive (Staphylococcus aureus, ATCC 29213 and Enterococcus faecalis, ATCC 29212) and two Gram-negative bacteria (Escherichia coli, ATCC 27853 and Pseudomonas aeruginosa, ATCC 25922). Animal pathogenic fungi were more resistant than the plant fungal pathogens. Based on the good activity of the DCM crude extract, the surprising selectivity in activity against different fungi coupled with reasonably good therapeutic indexes and the wide availability of T stans leaves opens up the possibility that a commercial product to protect plants against certain pathogens may be developed from T. stans leaves. Copyright / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2008. / Paraclinical Sciences / unrestricted

Lettuce (Lactuca sativa L.) seedlings diseases caused by soilborne pathogens are characterised by root rot, stem rot and damping-off of the seedlings that can occur at any time during growth. Fusarium solani, Pythium ultimum and Rhizoctonia solani are known to be the important destructive pathogens of lettuce, causing severe yield losses in South Africa. The aim of this research was to evaluate the effects of three selected fungicides to control these pathogens on lettuce seedlings. In this study the fungicides metalaxyl (Apron®), fludioxonil (Celest®) and mefenoxam (Subdue®) were applied at two concentrations as single and double doses on lettuce seedlings to determine their efficacy to control the pathogens Fusarium solani, Pythium ultimum and Rhizoctonia solani after significant reduction of mycelia growth was observed in vitro. Cultures of P. ultimum (UPGH024), R. solani (UPGH122) and F. solani (UPGH122) were obtained from the culture collection of the Department of Microbiology and Plant Pathology, University of Pretoria and cultivated on PDA for 2 days at 25ºC. Pasteurised soil was artificially inoculated with these pathogens. For the first experiment lettuce seeds were planted in polystyrene seedling trays at a depth of 1.0 cm. There were four replications of 50 seeds per treatment. In Experiment 2 pots (12 cm x 7 cm) were filled with pasteurised growing medium and 3-week old seedlings were transplanted. There were three replications of six pots containing three plants each. Seedling trays and pots were drenched with fungicides and placed in a randomised block design in a controlled environment room at 20- 26°C with a 12h-light/dark regime. The seedling trays and pots were rotated daily in the room. Seedling trays and pots were watered daily to maintain field capacity. The seedlings were able to grow larger in the pots than in seedling trays. It was confirmed that the treatment with fludioxonil (Celest®) at double and single dose inhibited the growth of the three fungi F. solani, P. ultimum and R. solani on lettuce seedlings without causing phytotoxicity. All three fungicides significantly reduced the diseases caused by the three pathogens. These findings are consistent with previous reports that fludioxonil, metalaxyl and mefenoxam can control oomycete fungi. There are few registered fungicides for the control of Fusarium solani, Pythium ultimum and Rhizoctonia solani on lettuce, therefore further work will aim to confirm these results in the field. / Dissertation (MInstAgrar)--University of Pretoria, 2008. / Microbiology and Plant Pathology / unrestricted

Face à l’explosion démographique mondiale actuelle, les rendements agricoles se doivent d’être les plus élevés possible. Afin de relever ce défi, l’utilisation de pesticides efficaces et éco-compatibles est devenue indispensable. Dans le cadre de la recherche de nouveaux composés répondants à ces objectifs, les produits naturels continuent de retenir l’attention des chercheurs. Parmi eux, nous nous sommes intéressés à la gougérotine, un peptidonucléoside découvert au sein d’une bactérie dans les années 60 et possédant un large spectre d’activités biologiques. Dans le but d’optimiser l’activité antifongique et de diminuer la toxicité de la molécule, plusieurs analogues ont été synthétisés en jouant notamment sur la nature de la base nucléique. Une des réactions clé au cœur de la synthèse de nucléoside est la N-glycosylation permettant la liaison glycosidique entre la base nucléique et un donneur de glycosyle. Au cours de la voie de synthèse des analogues peptidonucléosidiques, une étude méthodologique de la N-glycosylation a été réalisée mettant en jeu différents donneurs de glycosyle et bases nucléiques. Des tests préventifs ont ensuite été réalisés sur les composés obtenus afin d’évaluer leur potentiel antifongique. Grâce aux analogues de la gougérotine et aux intermédiaires synthétisés, une étude de relation structure-activité a été menée. / In the current context of the world demographic explosion, agricultural yields need to be as high as possible. The use of efficient and environment friendly pesticides has therefore become essential. In the framework of the discovery of new compounds, natural products remain an important source of inspiration. Among them, we focused on gougerotin, a peptidylnucleoside isolated from a bacteria in the 60’s which possess a broad spectrum of biologic activities. In order to improve antifungal potential and decrease the phytotoxicity of gougerotin, several analogues have been synthesized replacing the natural nucleobase. N-glycosylation is one of the key-reaction in peptidylnucleoside synthesis. During the synthesis of the analogues, a study of the N-glycosylation was carried out with three different donors and several bases. Protectives tests were realized with many pathogens to evaluate antifungal activity of our compounds and a structure-activity relationship was established.

Gray mold of strawberry, caused by Botrytis cinerea, is a very destructive pre- and post-harvest fruit rot. Outside of California, fungicide resistance in B. cinerea has been reported to every site-specific chemical class labeled for use against gray mold. One objective of this study was to characterize the resistance of 888 isolates of B. cinerea from California strawberry fields to ten active ingredients. Isolates were collected from the same planting block in 47 fields during the early-season (0 to 8 fungicide applications) and late-season (16 to 26 fungicide applications) of 2016. Sensitivity of each isolate was determined using the following active ingredients at a discriminatory dosage (μg/ml): boscalid (75), cyprodinil (4), fenhexamid (50), fludioxonil (0.5), fluopyram (10), iprodione (10), isofetamid (5), penthiopyrad (5), pyraclostrobin (10), and thiophanate-methyl (100). Resistance to each active ingredient was observed at varied frequencies (early-season %, late-season %): boscalid (12, 35), cyprodinil (12, 46), fenhexamid (53, 91), fludioxonil (1, 4), fluopyram (2, 7), iprodione (25, 8), isofetamid (0, 1), penthiopyrad (8, 25), pyraclostrobin (77, 98), and thiophanate-methyl (81, 96). Captan, boscalid, cyprodinil, fenhexamid, and fludioxonil were the most commonly used fungicides in surveyed strawberry fields. A selection of 100 isolates was identified to the species level. All isolates were B. cinerea, excluding one isolate of Botrytis mali. A fungicide resistance trial was conducted v to observe resistance responses in populations of B. cinerea. Frequencies of resistance to boscalid and fludioxonil remained unchanged despite consecutive applications of these fungicides. Frequency of resistance to fenhexamid increased when this fungicide was applied and decreased when it was not. This occurred in fungicide treatments including fungicide rotation, tank-mixing with captan, and consecutive applications of fenhexamid. Multi-fungicide resistance was widespread in California strawberries; isolates resistant to fenhexamid, thiophanate-methyl and pyraclostrobin were the most common phenotype. The frequency of resistance increased from the early-season to late-season for multiple active ingredients tested. This within-season change in frequency of resistance was tested and confirmed in a field trial, where common resistance management strategies failed to prevent the buildup of fenhexamid resistance. New and improved methods of resistance management may need to be enacted to ensure the future efficacy of site-specific fungicides.

The extraction and recovery of trace organic material from semi-solid and solid matrices is often the slowest and most error-prone step of an analytical method. The conventional liquid extraction techniques for solids and semi-solids materials (Soxhlet) have two main disadvantages. The first, large volumes of organic solvent are required, which can lead to sample contamination and "losses" due to volatilization during concentration steps. The second, to achieve an exhaustive extraction can require several hours to days. With the development of sophisticated instrumentation with detection limits in the picogram and femtogram levels, pressure is finally felt within the analytical community to develop and validate sample preparation procedures which can be used to rapidly isolate trace level organics from complex matrices.Because of its applicability to solid, semi-solid, and liquid matrices microwave-assisted (MAE) extraction has emerged as a powerful sample preparation technique. The objective of this research was to evaluate directly focused microwave energy for the isolation of systemic fungicide residues from woody plant tissues.The hallmark of microwave extraction (MAE) is accelerated dissolution kinetics as a consequence of the rapid heating processes that occur when a microwave field is applied to a sample. The current popularity of MAE resides mainly on its applicability to a wide range of sample types because the selectivity can be easily manipulated by altering solvent polarities.Propiconazole is a systemic fungicide, used to combat the fungal pathogen Ophiostoma ulmi, the casual agent of Dutch elm disease (DED). It was successfully extracted from treated Ulmus americana (elm tree) using MAE with a percent recovery of 395% in 15 minutes. Until now, techniques for rapid and efficient extraction of polar material from wood were non-existent. This work produces results much quicker than Supercritical Fluid Extraction (SFE). The influence of pH, microwave power, and time on extraction efficiency was also investigated. The extraction methodology was optimized and statistically validated.This MAE method combined with GC-MS was used to study the diffusion patterns and degradation of propiconazole in tree bark over extended time periods. Because of the complex nature of woody plant systems, it was realized that a more theoretical means must be used to determine the degradation rate of propiconazole in water systems. As a result, propiconazole was reacted with water under controlled temperature and pH conditions; to measure the degradation rate of propiconazole.The internal pH of elm sap is about 6.0; the slightly acidic environment and natural enzymes within the xylem vessels are known to catalyze the degradation of propiconazole (1). Novartis Inc. has marketed propiconazole as having fungicidal effects in injected elms for nearly two years. Our degradation studies have indicated much shorter lifetimes. To confirm our fate studies, the activation energy for the degradation reaction of propiconazole was calculated. This information provided valuable insight into revising dosage and treatment frequency for maximum protection of the elm against Dutch elm disease. Anti-fungal activity among metabolites was also explored. This is the first reported use of MAE to monitor the degradation of systemic pesticides in woody plant material. / Ph. D.

A study was conducted to determine the feasibility of utilizing potassium sorbate as a fungistatlc agent in country ham processing. The study was divided into three phases: the first utilized 60 and 90 day old cured country (long cut) ham; the second used country ham slices; and the third phase utilized 70 day old country cured (packer style cut) hams. Samples were incubated at various temperatures and relative humidities to determine the extent of protection offered by sorbate against fungal growth. Intensity of fungal growth was determined subjectively through periodic visible evaluations and were quantitated by culture plating methods. A UV spectrophotometric technique was utilized to determine the concentrations of sorbic acid deposited on ham surfaces or slices by various methods of application. Of the different methods of application that were tested, the 5% (W/V) 1 minute spray offered the lowest effective level for inhibition of fungal growth. The 5% l minute spray significantly lowered initial mold and yeast colony counts and protected the hams for 30 to 60 days under conditions conducive to fungal outgrowth (21.1±5°C and 70±5% relative humidity). An analogous 10% spray provided a slightly greater measure of mold inhibition than the 5% treatment under identical conditions. / Master of Science

Content: One of the main challenges of the tannery industry chain is to reduce the use of biocides and restricted substances and at the same time increase efficiency with the available products. Such conduct must permeate suppliers and the tanneries in order to obtain better results, diminish the biocide resistance dissemination, optimize costs and be ecologically friendly. In this sense, we present herein an updated review and discussion of the scientific and technological literature on the aspects involving the action of fungicides in tannery industry and how the application of this knowledge can reduce application of biocides and restricted substances in the tanning process. We have organized a review by consulting the databases PUBMED, Web of Science, Science direct, and all literature with excellence scientific support available. The review focused on: (i) Fungal diversity involved in wet-blue biodeterioration; (ii) Mechanisms of action of fungicides; (iii) Fungicide combinations to enhance activity; (iv) Fungal mechanisms of resistance and the known causes of resistance emergence. As a result of this study we are able to track the fungal phylogenetics (and relationship) responsible for leather biodeterioration enabling a guiding strategy for fungal biocide application. Moreover, understanding of the mechanisms of action and interaction between molecules can determines the extent of the biocides inhibitory effect in different fungal species. Fungicide effect could vary, and such information corroborates with the idea that even in the same species the interaction of the different molecules may vary, possibly due to variation in cytochrome protein. For example, the most accepted mechanism of action of azoles is the inhibition of synthesis of or direct interaction with ergosterol (present in all fungi). Considering that the target is always the same, a question arise, how do the distinct azoles present different activities upon fungal strains? As result of this study we show that structural differences will influence the higher or lower interaction of the azole functional group and consequently the activity. The appropriated knowledge of the mechanisms by which microbial cells might develop resistance, highlights the need for an improved understanding of the reasons for their emergence and greater attention to methods that can be used to prevent and control them. In this sense, a successful combination of biocide molecules enhances a synergetic effect, avoiding fungal mechanisms of resistance and reduces dosage of each compound, being effective against a variety of fungi. Take-Away: Transfer of knowledge from the author of the fundermentals of bicides and fungicides used within the leather industry and similar industries, their application methods and how to use in combination for maximum effect with minimum environmental impact.

In questo lavoro si intende indagare l'effetto degli anti-oidici più diffusi al fine di individuare nuovi approcci per la ricerca sui fungicidi. Le analisi statistiche mostrano che meptildinocap, zolfo, metrafenone e penconazolo, somministrati a dosi di etichetta, prevengono le infezioni di Erysiphe necator qualora applicati fino a 12 giorni prima dell'inoculazione. Meptildinocap e zolfo conservano una buona efficacia anche se applicati fino a 9 e 6 giorni dopo l'inoculazione. Meptildinocap neutralizza il massimo numero di conidi entro 6 giorni dal trattamento. La meta-analisi multivariata eseguita su prove di campo dimostra che tutti i fungicidi riducono la gravità delle infezioni su grappolo oltre l'80%, qualora applicati da 3 a 13 volte a dosi di etichette secondo il criterio fenologico. Nonostante cyflufenamid, quinoxyfen, fenarimol, fenarimol+zolfo, propiconazolo e kresoxim-metil+boscalid siano significativamente più efficaci dello zolfo, la loro applicazione ripetuta rappresenta una condizione favorevole all’insorgenza di resistenze. L’ approccio chemio-metrico all’ analisi dei dati ottenuti da microanalisi in microscopia SEM a raggi X mostra che meptildinocap induce modificazioni nei rapporti tra Ca e Al e P e S sulla parete dei Chasmoteci trattati. Tali modificazioni sono probabilmente dovute al dissolvimento della membrana plasmatica. Questi nuovi approcci possono rappresentare un'utile integrazione ai metodi già noti. / In this work the effect of the most widespread fungicides used for Erysiphe necator management is investigated in order to test new approaches to fungicide research. ANCOVA and Tukey’s post hoc tests showed that meptyldinocap, sulfur, metrafenone and penconazole administrated at label rates prevent E. necator infections when applied up to 12 days before inoculation. Meptyldinocap and sulfur preserve a good efficacy even when applied until 9 and 6 days after inoculation. Meptyldinocap significantly increases E. necator conidia mortality within 6 days exposure. The multi-treatment meta-analysis performed on field trials shows that all fungicides reduce disease severity over 80% on vine bunches when applied from 3 to 13 times at label rates with the phenological criterion. Although cyflufenamid, quinoxyfen, fenarimol, fenarimol+sulfur, propiconazole and kresoxim-methyl+boscalid are significantly more effective than sulfur their repeated application in vineyard represents an important E. necator resistance risk. The application of chemo-metric approach to data earned by SEM X-ray microanalysis shows that meptyldinocap leads to modifications in the relationships between Ca and Al and P and S in treated Chasmothecia wall. Such modifications are probably due to the plasma membrane disruption. The new approaches tested here may represent a useful integration of already known methods.