scholarly journals Regional and Field-Specific Factors Affect the Composition of Fusarium Head Blight Pathogens in Subtropical No-Till Wheat Agroecosystem of Brazil

2015 ◽  
Vol 105 (2) ◽  
pp. 246-254 ◽  
Author(s):  
Emerson M. Del Ponte ◽  
Piérri Spolti ◽  
Todd J. Ward ◽  
Larissa B. Gomes ◽  
Camila P. Nicolli ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Regional Differences ◽  
Head Blight ◽  
Wheat Varieties ◽  
Previous Crop ◽  
No Till ◽  
Fusarium Graminearum Species Complex ◽  
Specific Factors ◽  
Wheat Kernels ◽  
Genotype F

A multiyear survey of >200 wheat fields in Paraná (PR) and Rio Grande do Sul (RS) states was conducted to assess the extent and distribution of Fusarium graminearum species complex (FGSC) diversity in the southern Brazilian wheat agroecosystem. Five species and three trichothecene genotypes were found among 671 FGSC isolates from Fusarium head blight (FHB)-infected wheat heads: F. graminearum (83%) of the 15-acetyldeoxynivalenol (15-ADON) genotype, F. meridionale (12.8%) and F. asiaticum (0.4%) of the nivalenol (NIV) genotype, and F. cortaderiae (2.5%) and F. austroamericanum (0.9%) with either the NIV or the 3-ADON genotype. Regional differences in FGSC composition were observed, with F. meridionale and the NIV type being significantly (P < 0.001) more prevalent in PR (>28%) than in RS (≤9%). Within RS, F. graminearum was overrepresented in fields below 600 m in elevation and in fields with higher levels of FHB incidence (P < 0.05). Species composition was not significantly influenced by previous crop or the stage of grain development at sampling. Habitat-specific differences in FGSC composition were evaluated in three fields by characterizing a total of 189 isolates collected from corn stubble, air above the wheat canopy, and symptomatic wheat kernels. Significant differences in FGSC composition were observed among these habitats (P < 0.001). Most strikingly, F. meridionale and F. cortaderiae of the NIV genotype accounted for the vast majority (>96%) of isolates from corn stubble, whereas F. graminearum with the 15-ADON genotype was dominant (>84%) among isolates from diseased wheat kernels. Potential differences in pathogenic fitness on wheat were also suggested by a greenhouse competitiveness assay in which F. graminearum was recovered at much higher frequency (>90%) than F. meridionale from four wheat varieties inoculated with an equal mixture of F. graminearum and F. meridionale isolates. Taken together, the data presented here suggest that FGSC composition and, consequently, the trichothecene contamination in wheat grown in southern Brazil is influenced by host adaptation and pathogenic fitness. Evidence that F. meridionale and F. cortaderiae with the NIV genotype are regionally significant contributors to FHB may have significant implications for food safety and the economics of cereal production.

scholarly journals The Effect of Previous Crop Residues and Tillage on Fusarium Head Blight of Wheat

Plant Disease ◽  
2000 ◽  
Vol 84 (1) ◽  
pp. 71-76 ◽  
Author(s):  
R. Dill-Macky ◽  
R. K. Jones
Keyword(s):  
Fusarium Head Blight ◽  
Crop Residues ◽  
Cultural Practices ◽  
Conservation Tillage ◽  
Head Blight ◽  
Tillage Practices ◽  
Previous Crop ◽  
No Till ◽  
Chisel Plow ◽  
Spring Wheat Cultivar

Effects of previous crop residues and tillage practices on Fusarium head blight (FHB) of wheat were examined. Fusarium head blight was monitored in plots of the FHB-susceptible spring wheat cultivar Norm following crops of corn, wheat, and soybeans in 1995, 1996, and 1997. Moldboard plow, chisel plow, and no-till treatments were imposed perpendicular to crop strips to establish a range of residue levels in each of the previous crop residues. Fusarium head blight incidence and severity were greatest when wheat followed corn and least when wheat followed soybeans. Incidence and severity were lower in moldboard plowed plots than in either chisel plowed or no-till plots, although differences among chisel plow and no-till treatments were not apparent. Yields of wheat were approximately 15% lower in plots where wheat followed corn or wheat than in wheat following soybeans and were 10% greater in moldboard plowed plots than in either chisel plowed or no-till treatments. The deoxynivalenol (DON) content of harvested grain was significantly correlated with FHB incidence and severity. The DON level in wheat following soybeans, averaged across tillage treatments, was 25% lower than in wheat following wheat and 50% of the level in wheat following corn. These findings suggest that changes in regional tillage practices, principally the move toward conservation tillage and reduced-till systems, contributed to the recent FHB epidemics in the Upper Midwest. Because differences in the type and quantity of crop residues in small plots affected disease development, it is likely that local sources of inoculum, such as those within a grower's field, contribute directly to the inoculum load and disease potential. The implication of these findings is that selection of cultural practices aimed to reduce inoculum-borne residues will assist in the control of FHB.

scholarly journals Fusarium Head Blight: Effect of Infection Timing on Spread of Fusarium graminearum and Spatial Distribution of Deoxynivalenol within Wheat Spikes

2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Elias Alisaac ◽  
Anna Rathgeb ◽  
Petr Karlovsky ◽  
Anne-Katrin Mahlein
Keyword(s):  
Spatial Distribution ◽  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Fungal Biomass ◽  
Head Blight ◽  
Wheat Varieties ◽  
Fungal Dna ◽  
Infection Timing ◽  
Wheat Kernels ◽  
Days After Anthesis

Most studies of Fusarium head blight (FHB) focused on wheat infection at anthesis. Less is known about infections at later stages. In this study, the effect of infection timing on the development of FHB and the distribution of fungal biomass and deoxynivalenol (DON) along wheat spikes was investigated. Under greenhouse conditions, two wheat varieties were point-inoculated with Fusarium graminearum starting from anthesis until 25 days after anthesis. The fungus and fungal DNA were isolated from the centers and the bases of all the spikes but not from the tips for all inoculation times and both varieties. In each variety, the amount of fungal DNA and the content of DON and deoxynivalenol-3-glucoside (DON-3-G) were higher in the center than in the base for all inoculation times. A positive correlation was found between the content of fungal DNA and DON in the centers as well as the bases of both varieties. This study showed that F. graminearum grows downward within infected wheat spikes and that the accumulation of DON is largely confined to the colonized tissue. Moreover, F. graminearum was able to infect wheat kernels and cause contamination with mycotoxins even when inoculated 25 days after anthesis.

scholarly journals Relationship Between Efficacy of Fusarium Head Blight Chemical Control and Deoxynivalenol Contamination on Wheat Kernels

2020 ◽  
Vol 12 (9) ◽  
pp. 227
Author(s):  
Erlei Melo Reis ◽  
Mateus Zanatta ◽  
Andrea Camargo Reis
Keyword(s):  
Fusarium Head Blight ◽  
Chemical Control ◽  
Wheat Cultivar ◽  
Disease Incidence ◽  
Growing Season ◽  
Inverse Relation ◽  
Efficient Technology ◽  
Head Blight ◽  
No Till ◽  
Wheat Kernels

In field experiment carried out in the 2018 growing season we tried to show the inverse relation between the efficacy of fusarium head blight (FHB) chemical control and the deoxynivalenol (DON) concentration in harvested kernels. The wheat cultivar Tbio Mestre was established under no-till in soybean residues and in winter rotation with black oats. The leaf rust and yellow spot control was performed during the vegetative stage by spraying the whole experimental area with three applications of epoxiconazole + krezoxim methyl (0.7 L/ha). The most potent fungicides metconazole + pyraclostrobin (1.0 L/ha) + mancozeb (2.0 kg/ha), prothioconazole + trifloxystrobin (0.4 L/ha) and pydiflumetofen (1.0 L/ha) were compared to control FHB. Disease incidence in spikes, incidence in spikelets, or spikes severity, grain weight and yield were evaluated. DON concentration was. Using the most efficient technology available for FHB control, the hypothesis of the inverse relationship between disease intensity occurring naturally in spikes, and deoxinivalenol (DON) concentration in the harvested grains was confirmed. DON concentration in unsprayed grains was 3,675 and in the best treatments 821 to 1,067 ppb.

scholarly journals Disease Risk, Spatial Patterns, and Incidence-Severity Relationships of Fusarium Head Blight in No-till Spring Wheat Following Maize or Soybean

Plant Disease ◽  
2015 ◽  
Vol 99 (10) ◽  
pp. 1360-1366 ◽  
Author(s):  
Pierri Spolti ◽  
Denis A. Shah ◽  
José Maurício C. Fernandes ◽  
Gary C. Bergstrom ◽  
Emerson M. Del Ponte
Keyword(s):  
Fusarium Head Blight ◽  
Large Scale ◽  
Disease Risk ◽  
Random Pattern ◽  
Southern Brazil ◽  
Head Blight ◽  
Previous Crop ◽  
Regional Sources ◽  
Epidemiological Surveys ◽  
The Relationship

The first large-scale survey of Fusarium head blight (FHB) in commercial wheat fields in southern Brazil was conducted over three years (2009 to 2011). The objectives were to: (i) evaluate whether increased FHB risk is associated with within-field maize residue; (ii) determine the spatial pattern of FHB incidence; and (iii) quantify the relationship between FHB incidence and severity. FHB was assessed in a total of 160 fields between early milk and dough. Incidence ranged from 1.0 to 89.9% (median = 25%) and severity from 0.02 to 18.6% (median = 1.3%). FHB risk was neither lower nor higher in wheat following maize than in wheat following soybean. Only 18% of fields were classified as having aggregated patterns of FHB-symptomatic spikes. A binary power law description of the variances was consistent with an overall random pattern of the disease. These results conform with the hypothesis that FHB epidemics in southern Brazil are driven by sufficient atmospherically-transported inoculum from regional sources. The incidence-severity relationship was coherent across growing season, growth stage, and previous crop; one common fitted curve described the relationship across all observations. Estimating severity from incidence may be useful in reducing the workload in epidemiological surveys.

scholarly journals Activity of Demethylation Inhibitor Fungicide Metconazole on Chinese Fusarium graminearum Species Complex and Its Application in Carbendazim-Resistance Management of Fusarium Head Blight in Wheat

Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 929-937 ◽  
Author(s):  
Yabing Duan ◽  
Xian Tao ◽  
Huahua Zhao ◽  
Xuemei Xiao ◽  
Meixia Li ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Mycelial Growth ◽  
Species Complex ◽  
Resistance Management ◽  
Head Blight ◽  
Grain Yields ◽  
Significant Difference ◽  
Fusarium Graminearum Species Complex ◽  
Demethylation Inhibitor

Fusarium graminearum species complex (FGSC), causing Fusarium head blight (FHB) of wheat, has species-specific geographical distributions in wheat-growing regions. In recent years, benzimidazole resistance of FHB pathogens has been largely widespread in China. Although the demethylation inhibitor fungicide metconazole has been used for FHB control in some countries, no information about metconazole sensitivity of Chinese FHB pathogen populations and efficacy of metconazole in FHB control in China is available. In this study, the sensitivity of FGSC to metconazole was measured with 32 carbendazim-sensitive strains and 35 carbendazim-resistant strains based on mycelial growth. The 50% effective concentration values of 67 strains were normally distributed and ranged from 0.0209 to 0.0838 μg ml−1, with a mean of 0.0481 ± 0.0134 μg ml−1. No significant difference in metconazole sensitivity was observed between carbendazim-sensitive and -resistant populations. An interactive effect of metconazole and phenamacril, a novel cyanoacrilate fungicide approved in China against Fusarium spp., in inhibiting mycelial growth showed an additive interaction at different ratios. Furthermore, field trials to evaluate the effect of metconazole and metconazole + phenamacril treatments in FHB control, deoxynivalenol (DON) production, and grain yields were performed. Compared with the fungicides carbendazim and phenamacril currently used in China, metconazole exhibits a better efficacy for FHB control, DON production, and grain yields, and dramatically reduces use dosages of chemical compounds in the field. The mixture of metconazole and phenamacril at ratios of 2:3 and 1:2 showed the greatest efficacy for FHB control, DON production, and grain yields among all the fungicide treatments but its use dosages were higher in comparison with metconazole alone. In addition, FHB control, grain yields, and DON levels were significantly correlated with each other, showing that visual disease indices can be used as an indicator of grain yields and DON contamination. Meanwhile, the frequency of carbendazim-resistant alleles in F. graminearum populations was dramatically reduced after metconazole and phenamacril alone and the mixture of metconazole and phenamacril applications, indicating that metconazole and a mixture of metconazole and phenamacril can be used for carbendazim resistance management of FHB in wheat. Overall, the findings of this study provide important data for resistance management of FHB and reducing DON contamination in wheat grains.

Climate change impacts on the ecology of Fusarium graminearum species complex and susceptibility of wheat to Fusarium head blight: a review

2016 ◽  
Vol 9 (5) ◽  
pp. 685-700 ◽  
Author(s):  
M. Vaughan ◽  
D. Backhouse ◽  
E.M. Del Ponte
Keyword(s):  
Climate Change ◽  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Species Complex ◽  
Animal Health ◽  
Carbon Dioxide Concentration ◽  
Host Susceptibility ◽  
Head Blight ◽  
Fusarium Graminearum Species Complex ◽  
The Impact

Fusarium head blight (FHB) of wheat, caused mainly by a few members of the Fusarium graminearum species complex (FGSC), is a major threat to agricultural grain production, food safety, and animal health. The severity of disease epidemics and accumulation of associated trichothecene mycotoxins in wheat kernels is strongly driven by meteorological factors. The potential impacts of change in climate are reviewed from the perspective of the FGSC life cycle and host resistance mechanisms influenced by abiotic pressures at the ecological, physiological and molecular level. Alterations in climate patterns and cropping systems may affect the distribution, composition and load of FGSC inoculum, but quantitative information is lacking regarding the differential responses among FGSC members. In general, the coincidence of wet and warm environment during flowering enhances the risk of FHB epidemics, but the magnitude and direction of the change in FHB and mycotoxin risk will be a consequence of a multitude of effects on key processes affecting inoculum dynamics and host susceptibility. Rates of residue decomposition, inoculum production and dispersal may be significantly altered by changes in crop rotations, atmospheric carbon dioxide concentration ([CO2]), temperature and precipitation patterns, but the impact may be much greater for regions where inoculum is more limited, such as temperate climates. In regions of non-limiting inoculum, climate change effects will likely be greater on the pathogenic rather than on the saprophytic phase. Although the mechanisms by which abiotic stress influences wheat defences against Fusarium species are unknown, available data would suggest that wheat may be more susceptible to Fusarium infection under future climate conditions. Additional research in this area should be a priority so that breeding efforts and climate resilient management strategies can be developed.

scholarly journals Regional differences in the composition of Fusarium Head Blight pathogens and mycotoxins associated with wheat in Mexico

2018 ◽  
Vol 273 ◽  
pp. 11-19 ◽  
Author(s):  
Minely Cerón-Bustamante ◽  
Todd J. Ward ◽  
Amy Kelly ◽  
Martha M. Vaughan ◽  
Susan P. McCormick ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Regional Differences ◽  
Head Blight

scholarly journals Fumonisin B1 and zearalenone contamination of wheat in Croatia and influence of fungicide treatments

2010 ◽  
Vol 90 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Dario Ivic ◽  
Ana-Marija Domijan ◽  
Maja Peraica ◽  
Bogdan Cvjetkovic
Keyword(s):  
Fusarium Head Blight ◽  
Fumonisin B1 ◽  
Wheat Grain ◽  
Head Blight ◽  
Fusarium Head Blight Severity ◽  
Fungicide Efficacy ◽  
Disease Pressure ◽  
Wheat Kernels

In Croatia, a trial was conducted to determine the presence of theFusariummycotoxins fumonisin B1and zearalenone in wheat kernels and to evaluate the efficacy of nine fungicides on Fusarium head blight severity as well as fumonisin B1and zearalenone accumulation in wheat grain. Fumonisin B1and zearalenone were detected in all grain samples in mean concentrations ranging from 182.0 to 446.6 µg kg-1(fumonisin B1) and from 2.59 to 5.33 µg kg-1(zearalenone). No significant differences were found among fumonisin B1and zearalenone content in wheat grain for the different fungicide treatments. No correlation was revealed between Fusarium head blight severity and fumonisin B1or zearalenone content in wheat grain, nor between fungicide efficacy and fumonisin B1or zearalenone content in wheat grain. Under conditions of high disease pressure, efficacy of the fungicides was between 85.7% (tebuconazole + triadimefon) and 72.1% (carbendazim).

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