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Mycotoxins present a global food safety threat of our feed and food. Mycotoxins are toxic metabolites of certain fungi in agricultural products that are harmful to animal and human health. The presence of mycotoxins in these products depends on a variety of management and environmental factors in the field, during storage and/or processing of feed and food commodities. To date, information on mycotoxin management is available, but is not easy to access by supply chain actors. This study aimed to design, build and test a Decision Support System (DSS) that can help decision making on mycotoxin management by various actors along the feed and food supply chains. As part of this, available knowledge and data on mycotoxin prevention and control were collected and synthesised into easy to understand guidelines and tools for various groups of end-users. The DSS consists of four different modules: (a) static information module and (b) scenario analysis module, (c) dynamic module for forecasting mycotoxins, and (d) dynamic module for real-time monitoring of moulds/mycotoxins in grain silos. Intended end-users are all enduser groups for modules (a) and (b); growers and collectors for module (c) and; post-harvest storage managers for module (d). The DSS is user-friendly and accessible through PCs, tablets and smartphones (see https://mytoolboxplatform. com/). In various phases of the DSS development, the tool has been demonstrated to groups of end-users, and their suggestions have been taken into account, whenever possible. Also, a near final version has been tested with individual farmers on the easiness to use the system. In this way we aimed to maximise the DSS uptake by actors along the chain. Ultimately, this DSS will improve decision making on mycotoxin management; it will assist in reducing mycotoxin contamination in the key crops of Europe, thereby reducing economic losses and improving animal and human health.

El proyecto NOVATERRA (European Comission H2020 GA num. 101000554) empezó en otoño de 2020 con el objetivo de aportar estrategias sostenibles e integradas con el fin de eliminar o reducir significativamente el uso de pesticidas y su impacto en el medioambiente, para las plagas más habituales de olivar y viñedo. A los largo del 2021 se llevaron a cabo los primeros ensayos de campo para testar y validar estas estrategias que se sustentan sobre tres pilares: a) la búsqueda de productos alternativos a los fitosanitarios más controvertidos, b) el uso de tecnologías de agricultura inteligente para una aplicación más precisa de los productos y c) la gestión del suelo para un mejor manejo integrado y control de plagas más eficiente. Todo ello, en una fase más avanzada del proyecto, debe traducirse en itinerarios más eficaces y sostenibles para la gestión de plagas de los cultivos.

Fusarium poae is one of the Fusarium species commonly detected in wheat kernels affected by Fusarium Head Blight. Fusarium poae produces a wide range of mycotoxins including nivalenol (NIV). The effect of temperature on colony growth and NIV production was investigated in vitro at 5–40 °C with 5 °C intervals. When the data were fit to a Beta equation (R2 ≥ 0.97), the optimal temperature was estimated to be 24.7 °C for colony growth and 27.5 °C for NIV production. The effects of temperature on infection incidence, fungal biomass, and NIV contamination were investigated by inoculating potted durum wheat plants at full anthesis; inoculated heads were kept at 10–40 °C with 5 °C intervals for 3 days and then at ambient temperature until ripening. Temperature significantly affected the incidence of floret infection and fungal biomass (as indicated by DNA amount) in the affected heads but did not affect NIV content in the head tissue. Inoculation of potted plants with F. poae did not reduce yield.

Forecasting models for mycotoxins in cereal grains during cultivation are useful for pre-harvest and post-harvest mycotoxin management. Some of such models for deoxynivalenol (DON) in wheat, using two different modelling techniques, have been published. This study aimed to compare and cross-validate three different modelling approaches for predicting DON in winter wheat using data from the Netherlands as a case study. To this end, a published empirical model was updated with a new mixed effect logistic regression method. A mechanistic model for wheat in Italy was adapted to the Dutch situation. A new Bayesian network model was developed to predict DON in wheat. In developing the three models, the same dataset was used, including agronomic and weather data, as well as DON concentrations of individual samples in the Netherlands over the years 2001–2013 (625 records). Similar data from 2015 and 2016 (86 records) were used for external independent validation. The results showed that all three modelling approaches provided good accuracy in predicting DON in wheat in the Netherlands. The empirical model showed the highest accuracy (88%). However, this model is highly location and data-dependent, and can only be run if all of the input data are available. The mechanistic model provided 80% accuracy. This model is easier to implement in new areas given similar mycotoxin-producing fungal populations. The Bayesian network model provided 86% accuracy. Compared with the other two models, this model is easier to implement when input data are incomplete. In future research, the three modelling approaches could be integrated to even better support decision-making in mycotoxin management.

Podosphaera xanthii and Golovinomyces orontii are the causal agents of cucurbit powdery mildew. The effect of temperature on conidial germination, infection and sporulation was studied under controlled conditions. Conidia were inoculated on cucumber leaf discs, and incubated at six constant temperatures (from 10 to 35 degrees C in 5 degrees C steps) for 3 to 72 h to evaluate conidial germination and infection, and for 6-15 days to evaluate sporulation intensity. Germination took place at all tested temperatures, but was close to zero at 35 degrees C. The longest germ tubes measured in this experiment were 141.74 mu m for the secondary germ tube of P. xanthii at 20 degrees C after 48 h of incubation, and 67.92 mu m for G. orontii for the primary germ tube at 20 degrees C after 48 h of incubation. The optimal temperatures for conidial germination, infection and sporulation were 24.4, 25.7 and 22.3 degrees C, respectively, for P. xanthii, and 17.9, 17.3 and 14.9 degrees C, respectively, for G. orontii. Equations were developed to describe conidial germination with a coefficient of determination (R-2) of 0.85 and 0.90 for P. xanthii and G. orontii, respectively. Infection equations resulted in R-2 of 0.94 and 0.93 for P. xanthii and G. orontii, respectively; and for sporulation, R-2 of 0.75 and 0.76 for P. xanthii and G. orontii respectively, as a function of temperature. These results can be used to develop models for the risk of cucurbit powdery mildew under field conditions.

A 2-year field experiment was conducted to determine the effects of Fusarium sporotrichioides, F. langsethiae, or F. poae on durum wheat plants artificially inoculated at different growth stages. The percentage of symptomatic kernels was similar among the three species, but incidence of infected kernels was lower for F. langsethiae. Kernel colonization was higher when plants were inoculated before and during anthesis for F. sporotrichioides and F. poae, but unaffected by timing of inoculation for F. langsethiae. Production of T-2/HT-2 toxins was higher for F. sporotrichioides than for F. langsethiae. Significant accumulations of nivalenol were detected for F. poae. Across all three species, there was a weak correlation (r=0.16; P=0.031) between the incidences of symptomatic and infected kernels, but a stronger correlation (r=0.53; P<0.001) between infection incidence and the quantity of fungal DNA (species-specific) in kernels. Mycotoxin content was correlated (r>0.58; P<0.007) with infection incidence or fungal DNA in kernels, but only for F. sporotrichioides and F. poae.

Fusarium graminearum is the predominant component of the Fusarium head blight complex of wheat. F. graminearum ascospores, which initiate head infection, mature in perithecia on crop residues and become airborne. The effects of temperature (T) and moisture on perithecium production and maturation and on ascospore production on maize stalk residues were determined. In the laboratory, perithecia were produced at temperatures between 5 and 30°C (the optimum was 21.7°C), but matured only at 20 and 25°C. Perithecia were produced when relative humidity (RH) was ≥ 75% but matured only when RH was ≥ 85%; perithecium production and maturation increased with RH. Equations were developed describing perithecium production and maturation over time as a function of T and RH (R2 > 0.96). Maize stalks were also placed outdoors on three substrates: a grass lawn exposed to rain; a constantly wet, sponge-like foam exposed to rain; and a grass lawn protected from rain. No perithecia were produced on stalks protected from rain. Perithecia production and maturation were significantly higher on the constantly wet foam than on the intermittently wet lawn (both exposed to rain). Ascospore numbers but not their dispersal patterns were also affected by the substrate.

The effects of temperature (temp) and relative humidity (RH) on germination of Fusarium graminearum ascospores, and of dry periods (DP) of different lengths and of temp and RH during DP on ascospore survival were studied both in vitro and in planta. Optimal temperatures for ascospore germination at 100% RH were 20 and 25°C; germination was ≤5% when ascospores were incubated at 20°C and RH≤93.5%. Viable ascospores were found at all tested combinations of DP duration (0 to 48 h) × temp (5 to 40°C) or RH (32.5 to 100% RH). Germination declined as DP duration and temp increased. Germination was lower for ascospores kept at 65.5% RH during the DP than at 76.0%, 32.5%, or 93.5% RH. Equations were developed describing the relationships between ascospore germination, DP duration and temp or RH during DP. Durum wheat spikes were inoculated with ascospores and kept dry for 0 to 48h at approximately 15°C and 65% RH; plants were then kept in saturated atmosphere for 48h to favor infection. Fungal biomass, measured as F. graminearum DNA by qPCR, declined as DP increased to 24 and 48h at 3 and 9 days post infection (dpi) but not in spikes at maturity.

Maize residues on the soil surface are a major inoculum source of several fungal pathogens of maize.Because the moisture content of crop residues can greatly affect fungal survival and inoculum production,we studied the effects of rainfall and relative humidity (RH) on the moisture content in maize stalkresidues on bare soil and on soil under a wheat crop at the heading stage (i.e., when the canopy providesthe maximum soil cover). The moisture content of residues that were initially saturated and that werethen placed on soil outdoors declined to a minimum value after approximately 32 h. On each of thefollowing days and in the absence of rain, the moisture content showed a diurnal pattern with decreasingvalues between 08.00 and 18.00 h and increasing values between 18.00 and 08.00 h. The pattern wasthe opposite for vapor pressure deficit. A simple model was developed to predict the wetting–dryingdynamics of maize stalk residues based on environmental conditions. The model has three compartments:(i) wetting of maize stalk residues during rain; (ii) drying after rain; and (iii) diurnal fluctuations in theabsence of rain. The model was calibrated and then validated against independent data collected inItaly and France. Comparison of observed vs. predicted data showed no systematic deviations of modelpredictions from real observations, with R2= 0.84 and standard error of estimates = 8.7%. The correlationconcordance coefficient (=0.89) and model efficiency (=0.75) showed a satisfactory goodness-of-fit to thereal data, with a slight overestimation (coefficient of residual mass = 0.11). The model should be a usefulcomponent of models for those plant pathogens, including Aspergillus flavus, Fusarium verticillioides andGibberella zeae, that produce inoculum in maize residues.

Mycotoxin contamination is of great concern in durum wheat and pasta production in Italy. A long-term project was conducted to improve mycotoxin management, and this project had six stages, from basic research to large-scale application. In stage 1, research was conducted on the biology and epidemiology of the fungal species involved in the Fusarium head blight (FHB) complex. The results were used in stage 2 to develop a multispecies, mechanistic model that included the effect of host and weather on: (1) inoculum production and dispersal; (2) infection and disease onset; and (3) mycotoxin accumulation. The weather-driven model was then validated under different epidemiological conditions. In stage 3, the model was expanded to include those crop management options that influence the risk of FHB and mycotoxin contamination, i.e. growing area, host species and resistance level of the cultivar, previous crop, and soil tillage. In stage 4, the complete model was included in a web-based decision support system (DSS) named granoduro.net®. The DSS provides plot-specific and up-to-date decision supports about weather, fertilisation, crop growth, weed control, and disease and mycotoxin risk. In stage 5, the DSS, together with Good Agricultural Practices, was applied for 2 years in 25 pilot farms across Italy. DSS use reduced external inputs (i.e. seeds, fungicides, and fertilisers) and costs, maintained or increased crop yield and quality, and kept mycotoxin contamination below the legal limit. Thus, the DSS significantly increased farmer income and reduced emission of greenhouse gasses. In stage 6, in an agreement with Barilla (a pasta producing company), the DSS was successfully used to manage 18,000 ha of durum wheat across Italy during 2013-2014. The DSS is currently being improved to include additional Fusarium species and related toxins, and the sexual stage of Fusarium graminearum. DSSs for common wheat and barley are also under development.

Fusarium graminearum is a predominant component of the Fusarium head blight (FHB) complex of small grain cereals. Ascosporic infection plays a relevant role in the spread of the disease. A 3-year study was conducted on ascospore discharge. To separate the effect of weather on discharge from the effect of weather on the production and maturation of ascospores in perithecia, discharge was quantified with a volumetric spore sampler placed near maize stalk residues bearing perithecia with mature ascospores; the residues therefore served as a continuous source of ascospores. Ascospores were discharged from perithecia on 70% of 154 days. Rain (R) and vapor pressure deficit (VPD) were the variables that most affected ascospore discharge, with 84% of total discharges occurring on days with R 0.2 mm or VPD 11 hPa, and with 70% of total ascospore discharge peaks ( 30 ascospores/m3 air per day) occurring on days with R 0.2 mm and VPD 6.35 hPa. An ROC analysis using these criteria for R and VPD provided True Positive Proportion (TPP) = 0.84 and True Negative Proportion (TNP) = 0.63 for occurrence of ascospore discharge, and TPP = 0.70 and TNP = 0.89 for occurrence of peaks. Globally, 68 ascospores (2.5% of the total ascospores sampled) were trapped on the 17 days when no ascospores were erroneously predicted. When a discharge occurred, the numbers of F. graminearum ascospores sampled were predicted by a multiple regression model with R2 = 0.68. This model, which includes average and maximum temperature and VPD as predicting variables, slightly underestimated the real data and especially ascospore peaks. Numbers of ascospores in peaks were best predicted by wetness duration of the previous day, minimum temperature, and VPD, with R2 = 0.71. These results will help refine the epidemiological models used as decision aids in FHB management programs.

Fusarium head blight is a major disease of wheat; it alters the yield and grain quality. In a context of reduced use of pesticides and regulations on mycotoxins at harvest, ARVALIS in collaboration with the University of Piacenza is developing a model that aims to optimize treatment against F. graminearum, the main mycotoxins-producing species on wheat. This mechanistic model describes the sexual stage of the pathogen. A first prototype was developed based on climatic parameters. To understand better the model outputs and the influence of each of the model parameters on these outputs, a sensitivity analysis was performed through three methods: Morris, ANOVA and Random Forest. These methods gave consistent results, enabling us to identify the most influential parameters., La fusariose de l’épi est une des principales maladies du blé, elle altère le rendement ainsi que la qualité du grain. Dans un contexte de limitation de l’usage des produits phytosanitaires et d’une réglementation sur les teneurs en mycotoxines à la récolte, ARVALIS, en collaboration avec l’université de Piacenza, développe un modèle afin d’optimiser le traitement contre F. graminearum, principale espèce productrice de mycotoxines sur blé. Ce modèle dit mécaniste décrit la phase sexuée de l’agent pathogène. Un premier prototype a été développé, basé exclusivement sur des variables climatiques. Afin de bien en comprendre les sorties et l’influence de chacun des paramètres du modèle sur ces sorties, une analyse de sensibilité a été réalisée à travers 3 méthodes : Morris, ANOVA et Random Forest. Ces méthodes ont donné des résultats cohérents permettant d’identifier les paramètres les plus influents du modèle.

Le coltivazioni di grano del nord dell’Italia sono soggette ad attacchi di vari funghi patogeni; la diffusione e l’incidenza di queste malattie varia però da un areale all’altro, di stagione in stagione - in rapporto all’andamento meteorologico stagionale – e da coltura a coltura – in relazione alle scelte colturali e alla gestione agronomica. In questo contributo si è voluto delineare l’evoluzione delle principali malattie (oidio, ruggine bruna, septoriosi e fusariosi della spiga) dal 2006 al 2013.

Gibberella zeae (anamorph Fusarium graminearum) is a key species of Fusarium head blight and consequent mycotoxin accumulation in wheat grain. G. zeae produces inoculum on residues of the previous crops. The dynamic of perithecia production and maturation were studied in controlled conditions and in the field, to acquire information on ascospore dynamics during the season. Maize stalks inoculated with G. zeae were incubated at different temperatures (5 to 40°C) at 100% relative humidity (RH). Numbers and maturity class of perithecia were assessed once a week over 8 weeks. Perithecia were produced between 10 and 30°C. At optimum temperatures (20, 25°C), perithecia emerged after 7 days of incubation. Perithecia matured only at optimum temperatures, from 14 days of incubation onwards. Inoculated maize stalks were also incubated at 25°C between 62.5% and 100% RH, which correspond to 15 to 80% moisture of the stalks. Perithecia were produced at RH 75% and reached the maximum number at 100%. Perithecia matured only with RH85%. Studies were performed on different crops residues, inoculated and incubated at 20°C at 80% RH for 3 weeks. Perithecia were produced on all tested debris; emergence started after 9 days on rape, sugar beet and potato, which had the highest production, compared to wheat, maize, pea and sunflower. Infested stalks were exposed outside between March and July over two years, in three groups: i) always wet trough contact with a wet substrate, ii) kept dry by a protection from rain, iii) left in natural conditions. Perithecia dynamics were assessed twice a week. More perithecia and more rapid maturation occurred in the wet residues, while no perithecia were produced in the dry one. More perithecia were produced in the year with more rain. In conclusion, temperature, moisture and kind of residue influence the dynamic of perithecia production and maturation.

Fusarium Head Blight (FHB) is caused by a species complex of Fusarium and Microdochium. This disease, common in wheat, can induce losses of yield but also degrade safety quality of grains. Indeed, the most common species of Fusarium in France is Fusarium graminearum (teleomorph=Gibberella zeae) and it can produce toxins, in particular deoxynivalenol (DON) regulated by the European Commission for cereals intended for human consumption. As this standard has been in effect since July 1st 2006, it is critical for grain producers and processors to have a better knowledge of DON content as well as the factors influencing its level and the agronomic practices that reduce risk. Therefore, ARVALIS - Institut du vegetal has developed decision-making tools to help them manage this risk of grain contamination before its commercialisation. Three kinds of approaches have been performed: a decision-grid to help farmers spray, an epidemiologic model to assess the risk of infection by F. graminearum spores and a statistical model to predict DON content in grain before harvest. Decision grid and statistical model have been developed by exploiting data from a field survey started in 2001 in collaboration with grain store partners. Over 2700 field samples were harvested and analysed for their DON content. For each field, agronomic parameters and weather conditions during flowering were recorded. A variance analysis has led to the identification of critical factors involved in DON content, namely: the previous crop, the tillage practice, the susceptibility of wheat varieties to DON and the sum of rain around flowering. These factors have been integrated in a DON risk assessment grid which classifies risk categories according to agronomy and weather. This grid is now used by farmers to help them spray or not at flowering. Although this grid is useful for farmers, a model has been set up for grain collectors in order to manage DON risk in silo. The model is based on a linear regression wi

Fusarium graminearum causa la fusariosi della spiga nei cereali a paglia. Il fungo produce sia conidi che ascospore sui residui della coltura precedente, le ascospore sono prodotte in periteci. La produzione e maturazione di periteci e ascospore in risposta a diverse condizioni di temperatura e umidità relativa sono state studiate. Dato che le condizioni atmosferiche influenzano anche l’umidità del substrato su cui l’inoculo è prodotto, la relazione tra i fattori atmosferici e l’umidità dei residui colturali di mais è stata esaminata. I fattori atmosferici influenzano anche il rilascio delle ascospore. L’effetto della temperatura è stato studiato in vitro. Mediante esperimenti in condizioni naturali, sono state definite regole per l’individuazione di condizioni favorevoli al rilascio di ascospore sulla base di pioggia e deficit di pressione di vapore. La distribuzione delle ascospore e dei conidi all’interno della vegetazione del frumento è quindi stata studiata mediante l’uso di captaspore passivi. Le ascospore possono essere rilasciate e depositarsi sulle spighe in condizioni non favorevoli per la germinazione. La germinazione di ascospore sottoposte a periodi asciutti di diversa durata, e a diverse condizioni di temperatura e umidità relativa durante il periodo asciutto, è stata studiata sia in vitro che in planta., Fusarium graminearum causes Fusarium head blight of small-grain cereals. The fungus produces conidia and ascospores on the previous crop residues, ascospores are formed in perithecia. Production and maturation of perithecia and ascospores at several temperature and relative humidity conditions were studied. As environmental conditions also influence the moisture content of the substrate on which inoculum is produced, the relationship between environmental factors and moisture of maize residues was assessed. Environmental factors also influence ascospore discharge. The effect of temperature was studied in vitro. Experiments in natural condition allowed to define rules for conditions leading to ascospore discharge, based on rain and vapor pressure deficit. Once discharged, the distribution of ascospores and conidia in the wheat canopy was studied using passive spore traps. Ascospores can be discharged and deposit on wheat spikes also in conditions that are unfavorable for germination. Germination of ascospores incubated in dryness for periods of several length, in several condition of temperature and relative humidity during dryness, was studied both in vitro and in planta.