The effects of fungicides on Fusarium spp. and their associated mycotoxins in naturally infected winter wheat grain.

Field trials conducted at the Institute of Agriculture, Lithuanian Research Centre for Agriculture and For- estry (central part of Lithuania) in 2009 were aimed to evaluate the effect of fungicides on Fusarium Head Blight (FHB) in a naturally infected field. A single application of dimoxystrobin + epoxiconazole (Swing Gold), prothioconazole (Proline), metconazole (Juventus), tebuconazole (Folicur), prothioconazole + tebu- conazole (Prosaro) was applied to winter wheat cv. ‘Zentos’ at the manufacturer’s recommended doses at anthesis (BBCH 65). The FHB incidence and severity were assessed at milk and hard maturity stages. The percentage of Fusarium infected grain and deoxynivalenol (DON), zearalenone (ZEN) and T-2 toxin (T-2) concentrations in harvested grain were determined. In all fungicide treated plots a significant reduction of FHB incidence and severity was determined; however the fungicides did not exert any effect on the amount of Fusarium–infected grain as compared with the untreated control. A reduction of  DON, ZEN and T-2 contents in grain was determined in tebuconazole treatments. Fusarium avenaceum (Fr.) Sacc, F. culmorum (W. G. Sm.) Sacc., F. poae (Peck) Wollenw, F. sporotrichioides Sherb. and F. tricinctum (Corda) Sacc were identi- fied in wheat grain, F. poae was prevalent

Natural Occurrence of Fusarium Mycotoxins in Oil Crop Seed

Oilseeds are a perfect medium for microfungi spread and mycotoxin production. With increasing demand for oil crop produce such research has gained a special relevance since research evidence on this issue is scarce. During 2007-2009, prevalent fungi genera, including Fusarium genus, potential producer of deoxynivalenol (DON), zearalenone (ZEA), T-2 toxin (T-2) etc. were determined in our tests. The ELISA immunoenzymatic method and Veratox Fast kits were used to identify and quantify mycotoxins, while Fusarium fungi species were identified using conventional fungi determination techniques. Higher Fusarium fungi contamination level was found on linseed compared with that on spring or winter rapeseed. The difference was even more obvious in different experimental years, however, having identified Fusarium species, F. avenaceum and F. oxysporum were found to be prevalent in the seed of all crop species tested. In 2009, spring rape samples were found to contain F. dimerum which is a significant human pathogen.The presence of DON was identified in 18.2-100%, ZEA in 40 -100%, and T-2 toxin in 100% of seed samples of all oil crop species tested. From the food safety viewpoint, the concentrations determined did not exceed the levels hazardous for health, laid out in the EU regulations, however, the effect of low toxin concentrations is slow and the negative consequences manifest themselves only after some time and in various forms, which poses a serious health risk for humans and animals

The Effectiveness of Digestate Use for Fertilization in an Agricultural Cropping System

The need to find and maximize the use of alternative sources of nutrients for plants and soil environment have been on the forefront of research in sustainable agriculture. These alternatives have to be affordable, accessible, reproduceable, and efficient to compete with established inorganic fertilizers while at the same time reduce any potential negative impacts on the environment. We aimed to evaluate the effectiveness of digestate fertilization in an agricultural system over a period of three years. The digestate utilized in the study consisted of animal waste-based digestates, namely pig manure digestate, chicken manure digestate, and cow manure digestate, and were compared with synthetic nitrogen fertilizer. Every year, the digestate and the synthetic nitrogen fertilizer were split applied at the rate of 90 and 80 kg N ha−1. The soil chemical composition after three years of fertilization showed a slight decrease, significantly different nitrogen and carbon changes while phosphorus and potassium were significantly higher in the digestate treatments. The third year of digestate application showed higher grain yield than previous years and the yield from the digestate treatments were significantly different from the synthetic nitrogen fertilizer. The nitrogen use efficiency for the three years was in the range of 20–25 percent in the digestate treatments, with a strong correlation between the nitrogen use efficiency and the grain yield. There were varied results in the grain quality and straw quality in the digestate and synthetic nitrogen fertilizer with no clear trend observed. Our results showed a relatively high potential of animal waste digestates over the short to mid-term use with a positive result obtained in comparison to synthetic nitrogen fertilizer under favorable climatic conditions

Toxigenicity of <i>F. graminearum</i> Residing on Host Plants Alternative to Wheat as Influenced by Environmental Conditions

Fusarium graminearum is an important pathogen that causes Fusarium head blight (FHB) in several cereal crops worldwide. The potential of this pathogen to contaminate cereals with trichothecene mycotoxins presents a health risk for both humans and animals. This study aimed to evaluate the potential of different trichothecene genotypes of F. graminearum isolated from an alternative host plant to produce mycotoxins under different spring wheat grain incubation conditions. Fourteen F. graminearum strains were isolated from seven alternative host plants and identified as 3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON) genotypes. These strains were cultivated on spring wheat grains at 25 °C and 29 °C for 5 weeks. The mycotoxins produced were analysed with a high-performance liquid chromatograph (HPLC) coupled to a Thermo Scientific TSQ Quantiva MS/MS detector. The obtained results showed that the F. graminearum strains from alternative host plants could produce nivalenol (NIV), deoxynivalenol (DON), fusarenon-X (FUS-X), 3-ADON, deoxynivalenol-3-ß-d-glucoside (D3G), 15-ADON, and zearalenone (ZEA). F. graminearum strains produced DON and ZEA under both temperatures, with the mean concentrations varying from 363 to 112,379 µg kg−1 and from 1452 to 44,816 µg kg−1, respectively. Our results indicated the possible role of dicotyledonous plants, including weeds, as a reservoir of inoculum sources of F. graminearum-induced Fusarium head blight, associated with the risk of mycotoxin contamination in spring wheat

The effect of different tillage-fertilization practices on the mycoflora of wheat grains

A two-factor field experiment was carried out at the Lithuanian Institute of Agriculture during the period 2005-2008. The influence of different tillage and fertilization practices on wheat grain fungal contamination was evaluated. Grain surface contamination and internal grain infection with fungi were quantified using agar tests. Purified colonies were identified using different manuals. A total of 16 fungal genera were identified in spring and winter wheat grains. Alternaria infected 46.3% - 99.9%, Cladosporium 26.9% - 77.8%, Fusarium 0.9% - 37.1%, Penicillium 1.3% - 2.5% of grains tested. Winter wheat grain surface contamination by fungi ranged from 7.2 × 103 to 24.8 × 103 of colony forming units per g of grain (cfu g-1), spring wheat from 14.8 × 103 to 80.3 × 103 cfu g-1. No-tillage increased winter wheat grain infection by Alternaria, Aspergillus and Cladosporium species and total count of cfu g-1 on spring wheat grain surface. High fertilizer rates resulted in an increase in spring wheat grain infection by Fusarium and Penicillium species and total count of cfu g-1 on both spring and winter wheat grain surface.vo

Susceptibility of non-cereal crops to Fusarium graminearum complex and their role within cereal crop rotation as a source of inoculum for Fusarium head blight

Fusarium graminearum, the cause of Fusarium head blight (FHB), is an important cereal pathogen. Moreover, some non-graminaceous crops are also known to be susceptible to F. graminearum infection. This study assessed the presence of F. graminearum species complex on non-cereal plants, grown in a cereal crop rotation and evaluated its pathogenicity to non-cereal plants in vitro and to spring wheat under field conditions. The relative density of Fusarium species isolated from oilseed rape, pea, potato and sugar beet plants was assessed in 2015 and 2016. A total of 403 isolates of Fusarium spp. were obtained from non-cereal plants and only 5% of the isolates were identified as F. graminearum. The pathogenicity test revealed that isolates of F. graminearum from spring wheat and non-cereal plants caused discolourations on leaves of faba bean, fodder beet, oilseed rape, pea, potato and sugar beet. The pea was the crop most susceptible to F. graminearum isolated from spring wheat. The pathogenicity of F. graminearum from sugar beet, oilseed rape, pea and potato to the same hosts differed depending on isolate and inoculated plant. Under field conditions, F. graminearum isolates from pea, potato, oilseed rape and wild viola were able to cause typical FHB symptoms in spring wheat. Based on the information generated in this study, we conclude that under congenial conditions, growing faba bean, pea, sugar beet, fodder beet, oilseed rape and potato plants in a cereal crop rotation may serve as alternative or reservoir hosts for F. graminearum pathogens

The prevalence of deoxynivalenol and its derivatives in the spring wheat grain from different agricultural production systems in Lithuania

<p>Deoxynivalenol (DON) together with two acetylated derivatives, 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) occurs in cereal grains and their products. Co-occurrence of DON and acetylated derivatives in cereal grain is detected worldwide. Until now, DON and its derivatives have been considered equally toxic by health authorities. In this study, we analysed 103 samples of spring wheat grain, originating from the fields of different production systems in Lithuania, for the co-occurrence of type-B trichothecenes (DON, 3-ADON, 15-ADON). The samples were classified according to the production system—organic, sustainable and intensive. Mycotoxin levels in the spring wheat grain samples were determined by the HPLC method with UV detection. The type-B trichothecenes were found to be present at higher concentrations in the grain from the intensive production system. Eighty-one percent of the spring wheat grain samples from the intensive production system were co-contaminated with a combination of DON+3-ADON+15-ADON, 1% with DON+3-ADON. Additionally, DON+15-ADON and DON were found in 5% and 10% of the tested samples, respectively. Two percent of the samples were free from mycotoxins. In the grain samples from the sustainable production system, DON and a combination of DON+3-ADON showed a higher incidence – 47% and 23%, respectively. The samples with a combination of DON+3-ADON+15-ADON accounted for 18%. Completely different results were obtained from the analyses of organic grain samples. A large number of the organic spring wheat grain samples were contaminated with DON+3-ADON (55%) or DON (36%). The combination of DON+3-ADON+15-ADON was not present, while DON+15-ADON was present in 9% of the samples tested. The production systems did not lead to significant differences in mycotoxin levels, although a trend toward higher incidence and higher contamination was observed for the samples from the intensive and sustainable production systems.</p

Susceptibility of non-cereal crops to Fusarium graminearum complex and their role within cereal crop rotation as a source of inoculum for Fusarium head blight

Fusarium graminearum, the cause of Fusarium head blight (FHB), is an important cereal pathogen. Moreover, some non-graminaceous crops are also known to be susceptible to F. graminearum infection. This study assessed the presence of F. graminearum species complex on non-cereal plants, grown in a cereal crop rotation and evaluated its pathogenicity to non-cereal plants in vitro and to spring wheat under field conditions. The relative density of Fusarium species isolated from oilseed rape, pea, potato and sugar beet plants was assessed in 2015 and 2016. A total of 403 isolates of Fusarium spp. were obtained from non-cereal plants and only 5% of the isolates were identified as F. graminearum. The pathogenicity test revealed that isolates of F. graminearum from spring wheat and non-cereal plants caused discolourations on leaves of faba bean, fodder beet, oilseed rape, pea, potato and sugar beet. The pea was the crop most susceptible to F. graminearum isolated from spring wheat. The pathogenicity of F. graminearum from sugar beet, oilseed rape, pea and potato to the same hosts differed depending on isolate and inoculated plant. Under field conditions, F. graminearum isolates from pea, potato, oilseed rape and wild viola were able to cause typical FHB symptoms in spring wheat. Based on the information generated in this study, we conclude that under congenial conditions, growing faba bean, pea, sugar beet, fodder beet, oilseed rape and potato plants in a cereal crop rotation may serve as alternative or reservoir hosts for F. graminearum pathogens

Modelling the Effects of Weather Conditions on Cereal Grain Contamination with Deoxynivalenol in the Baltic Sea Region

Fusarium head blight (FHB) is one of the most serious diseases of small-grain cereals worldwide, resulting in yield reduction and an accumulation of the mycotoxin deoxynivalenol (DON) in grain. Weather conditions are known to have a significant effect on the ability of fusaria to infect cereals and produce toxins. In the past 10 years, severe outbreaks of FHB, and grain DON contamination exceeding the EU health safety limits, have occurred in countries in the Baltic Sea region. In this study, extensive data from field trials in Sweden, Poland and Lithuania were analysed to identify the most crucial weather variables for the ability of Fusarium to produce DON. Models were developed for the prediction of DON contamination levels in harvested grain exceeding 200 µg kg−1 for oats, spring barley and spring wheat in Sweden and winter wheat in Poland, and 1250 µg kg−1 for spring wheat in Lithuania. These models were able to predict high DON levels with an accuracy of 70–81%. Relative humidity (RH) and precipitation (PREC) were identified as the weather factors with the greatest influence on DON accumulation in grain, with high RH and PREC around flowering and later in grain development and ripening correlated with high DON levels. High temperatures during grain development and senescence reduced the risk of DON accumulation. The performance of the models, based only on weather variables, was relatively accurate. In future studies, it might be of interest to determine whether inclusion of variables such as pre-crop, agronomic factors and crop resistance to FHB could further improve the performance of the models