The Role of Climatic Condition on Micotoxin Production in Cereal

Veterinary Research Communications -     

A dynamic risk assessment model (FUMAgrain) of fumonisin synthesis by Fusarium verticillioides in maize grain in Italy

Fumonisin contamination of maize grain starts in the field. Forecasting Fusarium infection and fumonisin synthesis could allow operators in the field to control contamination during the growing season and to make the best agronomic decisions for high quality yields while respecting the limits imposed by the European Union.A research project to develop a decision support system for the control of field-phase fumonisin contamination began in Italy in 2003. This paper presents a preliminary version of the engine of the decision support tool: FUMAgrain, a dynamic risk assessment model developed with data from the north of Italy. The structure of FUMAgrain is based on the pathosystem formed by maize, F. verticillioides and Ostrinia nubilalis (European Corn Borer). The elements of the pathosystem are simulated by three sub-models: (i) maize development, (ii) F. verticillioides infection and fumonisin synthesis, (iii) European Corn Borer wounding activity on maize grain. Inputs to the model are (i) planting date, (ii) hourly meteorological data including temperature, relative humidity, wind speed and rain intensity, (iii) information on the phenological development of the hybrid planted (flowering and dry-down), and (iv) information about the chemical treatment against European Corn Borer. FUMAgrain gives an initial risk alert at the end of flowering based on the meteorological conditions during this phase. A second alert follows maturation when an assessment is made from (i) maize grain moisture, (ii) European Corn Borer damage to the ear, and (iii) fumonisin synthesis risk. Following calibration and validation with data FUMAgrain demonstrated its good capability to simulate fumonisin synthesis in maize grain in Italy (calibration: R² = 0.70; validation: R² = 0.71) and its usefulness for determining the optimal harvest date while respecting grain safety levels required by the international market and limiting moisture content, hence drying costs.     

Effect of nitrogen fertilization on yield and quality of durum wheat cultivated in northern Italy and their interaction with different soils and growing seasons

Durum wheat in temperate regions can lead to yields with higher technological quality and stability compared to Mediterranean areas. The aim of this study was to determine the effects of nitrogen (N fertilization on grain yield and quality, in different pedo-climatic conditions of temperate areas. Field experiments were conducted in two sites (sandy-loam and silty-clay-loam) in Northern-West Italy for three years: five different N rates, two different types of fertilizers (ammonium nitrate, nutritional activator, slow-release fertilizer) were compared considering yield, protein content and yellowberry. N fertilizer rate had a more consistent effect on protein than yield; the response was affected by soil texture and rainfall during the growing season. The use of different types of fertilizer seem to play a minor role. The management of N fertilization must consider mainly the effect on quality parameters of N rates and rainfall during the growing season and their interaction with soil texture.     

Toxicity and persistence of three pyrethroids for the control of cereal bugs on common wheat

Journal of Pest Science - Sunn pests are responsible for serious kernel damage on wheat (Triticum aestivum L., Poaceae), affecting bread-making quality from their feeding at the late milk-ripe...     

A decision tool for evaluating the agronomic risk of exposure to fumonisins of different maize crop management systems in Italy

Fumonisins constitute a group of carcinogenic metabolites produced mainly by Fusarium verticillioides, the most common fungi associated with maize grain. The limits fixed for fumonisins in maize for food and feed by the European Union (EU) could represent a serious problem for maize areas in the south of Europe where F. verticillioides encounters extremely favourable meteorological and environmental conditions for its life cycle. Prevention strategies through pre-harvest agronomic management can achieve the quality and safety standards required by EU regulations.On the basis of results from agronomic field trials conducted in the North of Italy, the first version of an agronomic decision tool has been created to help farmers, collectors and processors manage fumonisin contamination in order to respect the EU fumonisin limits and the constraints required by a given market outlet. The tool is based on the concept of agronomic exposure to fumonisin risk (AEFR), which is a qualitative evaluation of the impact that a crop management system can have on fumonisin contamination.The validation has shown the validity of the decision tool, which was able to correctly classify the crop management systems of real farms according to their agronomic exposure to fumonisin risk: increasing levels of fumonisin contamination corresponded to increasing AEFR levels.     

Comparison of integrated field programmes for the reduction of fumonisin contamination in maize kernels

Fusarium verticillioides is a common maize pathogen which causes diseases on ears and synthesis of the mycotoxins, fumonisins, in kernels. Fumonisin production is influenced by both environmental conditions and agricultural inputs during growth and maturation of the maize plant. The aim of this research was to evaluate the effect of crop management techniques on fumonisin contamination in maize kernels. Experiments were conducted in Northern Italy during 2006 and 2007 using two maize hybrids with different precocity. Factors evaluated were seed planting time (March versus May), plant density (65,000 plants versus 80,000 plants per ha), N fertilization (200 kg N versus 400 kg N per ha), and chemical treatment to control European maize borer (ECB) (yes versus no). These factors were analyzed were as follows: (T1) May sowing, high plant density and N fertilization, (T2) March sowing time, high plant density and N fertilization, (T3) March sowing time, low plant density and balanced N fertilization, (T4) the same agronomic techniques as T3 plus a chemical treatment to control European maize borer. Ears were analyzed morphologically for ECB incidence and severity. Subsequently, kernels were analyzed chemically for fumonisins. Fumonisin contamination was reduced by 57%, 69% and 86% for T2, T3 and T4, respectively, compared to T1. This study clearly underlines that the application of good agricultural practices (GAP) in crop management strategies can effectively control fumonisin contamination of maize kernels.     

Effect of foliar treatments to durum wheat on flag leaf senescence, grain yield, quality and deoxynivalenol contamination in North Italy

Since the production of durum wheat in the drier areas of the Mediterranean Basin is characterized by high variability in terms of yield and grain quality, there is also considerable interest in developing durum wheat in the northern regions, where the pedo-climatic conditions can offer the possibility of obtaining grain yields with higher technological quality and stability. However, the climatic conditions in the northern regions make durum wheat more prone to fungal foliar disease, particularly to Septoria Tritici Blotch (Septoria tritici Rob.) and to Fusarium Head Blight (Fusarium graminearum Petch and Fusarium culmorum Sacc.), with the consequent occurrence of DON in grains.Field experiments have been conducted over two growing seasons at four sites in North West Italy to evaluate the effect of fungicides and foliar nitrogen fertilizer application on durum wheat yield and grain quality. Five combinations of foliar application were compared at each site and each year (untreated control, azole fungicide application at heading, strobilurin fungicide at the stem elongation stage and/or at heading, the addition of a foliar N fertilizer to a fungicide programme). The following parameters were analysed: Septoria Tritici Blotch (STB) severity, flag leaf greenness using a chlorophyll meter, grain yield, test weight, grain protein content, ash content, vitreousness, Fusarium Head Blight (FHB) incidence and severity and deoxynivalenol (DON) contamination. The collected data underline that the cultivation of durum wheat at the climatic conditions of North Italy is actually risky and needs a direct control of fungal disease, which would be able to reduce the development of both foliar and head attacks. The double treatment, with a strobilurin application during the stem elongation stage and azole at heading, results to be an essential practice and showed advantages in terms of the delay of flag leaf senescence (+27%), STB control (+31), FHB control (+11%), yield (+32%) and DON contamination (−45%), compared to the untreated control. Other foliar treatments at heading, such as strobilurin or foliar N fertilizer applications, do not seem to provide any further advantage, for either grain yield or quality. No significant effect of fungicide or foliar N fertilizer application was recorded on the protein or ash concentration or vitreousness.     

Effect of fungicide and foliar fertilizer application to winter wheat at anthesis on flag leaf senescence, grain yield, flour bread-making quality and DON contamination

In this study, field experiments have been conducted over three growing seasons to evaluate the effect of fungicides (triazoles and strobilurins) and a foliar fertilizer application to winter wheat at anthesis on flag leaf senescence, grain yield, bread-making quality, Fusarium head blight (FHB) disease and deoxynivalenol (DON) contamination.Flag leaf greenness was significantly influenced by the fungicide application. A delay in flag leaf senescence following triazole use did not increase grain yield. No effects of fungicide application on protein concentration were recorded. The application of strobilurin to a triazole programme did not significantly delay senescence of the flag leaf or increased yield, compared to the triazole-only application, while a consistent benefit was observed for dough strength (W). The triazole application led to significantly lower FHB symptoms and DON contamination, while the triazole-strobilurin fungicides programme led to an increase in DON contents, that were often higher than the untreated controls.Grain yield and quality were improved when a foliar feed containing macro- and micro-nutrients was added to a triazole fungicide programme, with no additional risk for DON contamination. Compared to the strobilurin fungicide application, the foliar fertilizer led to a longer delay of the flag leaf senescence and higher bread-making quality.