scholarly journals Relationship Between Visual Estimates of Fusarium Head Blight Intensity and Deoxynivalenol Accumulation in Harvested Wheat Grain: A Meta-Analysis

2005 ◽  
Vol 95 (10) ◽  
pp. 1225-1236 ◽  
Author(s):  
P. A. Paul ◽  
P. E. Lipps ◽  
L. V. Madden

The association between Fusarium head blight (FHB) intensity and deoxynivalenol (DON) accumulation in harvested grain is not fully understood. A quantitative review of research findings was performed to determine if there was a consistent and significant relationship between measures of Fusarium head blight intensity and DON in harvested wheat grain. Results from published and unpublished studies reporting correlations between DON and Fusarium head blight “index” (IND; field or plot-level disease severity), incidence (INC), diseased-head severity (DHS), and Fusarium-damaged kernels (FDK) were analyzed using meta-analysis to determine the overall magnitude, significance, and precision of these associations. A total of 163 studies was analyzed, with estimated correlation coefficients (r) between -0.58 and 0.99. More than 65% of all r values were >0.50, whereas less that 7% were <0. The overall mean correlation coefficients for all relationships between DON and disease intensity were significantly different from zero (P < 0.001). Based on the analysis of Fisher-transformed r values ( zr values), FDK had the strongest relationship with DON, with a mean r of 0.73, followed by IND (r = 0.62), DHS (r = 0.53), and INC (r = 0.52). The mean difference between pairs of transformed zr values (zd ) was significantly different from zero for all pairwise comparisons, except the comparison between INC and DHS. Transformed correlations were significantly affected by wheat type (spring versus winter wheat), study type (fungicide versus genotype trials), and study location (U.S. spring- and winter-wheat-growing regions, and other wheat-growing regions). The strongest correlations were observed in studies with spring wheat cultivars, in fungicide trials, and in studies conducted in U.S. spring-wheat-growing regions. There were minor effects of magnitude of disease intensity (and indirectly, environment) on the transformed correlations.

2007 ◽  
Vol 97 (2) ◽  
pp. 211-220 ◽  
Author(s):  
P. A. Paul ◽  
P. E. Lipps ◽  
D. E. Hershman ◽  
M. P. McMullen ◽  
M. A. Draper ◽  
...  

A meta-analysis of the effect of tebuconazole (e.g., Folicur 3.6F) on Fusarium head blight and deoxynivalenol (DON) content of wheat grain was performed using data collected from uniform fungicide trials (UFTs) conducted at multiple locations across U.S. wheat-growing regions. Response ratios (mean disease and DON levels from tebuconazole-treated plots, divided by mean disease and DON levels from untreated check plots) were calculated for each of 139 studies for tebuconazole effect on Fusarium head blight index (IND; field or plot-level disease severity, i.e., mean proportion of diseased spikelets per spike) and 101 studies for tebuconazole effect on DON contamination of harvested grain. A random-effects meta-analysis was performed on the log-transformed ratios, and the estimated mean log ratios were transformed to estimate the mean (expected) percent control for IND ( CIND ) and DON ( CDON). A mixed effects meta-analysis was then done to determine the effects of wheat type (spring versus winter wheat) and disease and DON levels in the controls on the log ratios. Tebuconazole was more effective at limiting IND than DON, with CIND and CDON values of 40.3 and 21.6%, respectively. The efficacy of tebuconazole as determined by the impact on both IND and DON was greater in spring wheat than in winter wheat (P < 0.01), with a 13.2% higher CIND and a 12.4% higher CDON in spring wheat than in winter wheat. In general, CIND and CDON were both at their lowest values (and not significantly different from 0) when mean IND and DON in the controls, respectively, were low (≤2% for IND and <1 ppm for DON). CIND was 25% higher in studies with mean IND between 2 and 15% than in studies with mean IND ≤ 2%, whereas CDON was 28.8% higher in studies with mean DON between 1 and 10 ppm than in studies with mean DON < 1 ppm. The between-study variance was significantly greater than 0 (P < 0.01), indicating considerable (unexplained) variability in percent control.


2006 ◽  
Vol 96 (9) ◽  
pp. 951-961 ◽  
Author(s):  
P. A. Paul ◽  
P. E. Lipps ◽  
L. V. Madden

A total of 126 field studies reporting deoxynivalenol (DON; ppm) content of harvested wheat grain and Fusarium head blight index (IND; field or plot-level disease severity) were analyzed to determine the overall mean regression slope and intercept for the relationship between DON and IND, and the influence of study-specific variables on the slope and intercept. A separate linear regression analysis was performed to determine the slope and intercept for each study followed by a meta-analysis of the regression coefficients from all studies. Between-study variances were significantly (P < 0.05) greater than 0, indicating substantial variation in the relationship between the variables. Regression slopes and intercepts were between -0.27 and 1.48 ppm per unit IND and -10.55 to 32.75 ppm, respectively. The overall mean regression slope and intercept, 0.22 ppm per unit IND and 2.94 ppm, respectively, were significantly different from zero (P < 0.001), and the width of the 95% confidence interval was 0.07 ppm per unit IND for slope and 1.44 ppm for intercept. Both slope and intercept were significantly affected by wheat type (P < 0.05); the overall mean intercept was significantly higher in studies conducted using winter wheat cultivars than in studies conducted using spring wheat cultivars, whereas the overall mean slope was significantly higher in studies conducted using spring wheat cultivars than in winter wheat cultivars. Study location had a significant effect on the intercept (P < 0.05), with studies from U.S. winter wheat-growing region having the highest overall mean intercept followed by studies from Canadian wheat-growing regions and U.S. spring wheat-growing regions. The study-wide magnitude of DON and IND had significant effects on one or both of the regression coefficients, resulting in considerable reduction in between-study variances. This indicates that, at least indirectly, environment affected the relationship between DON and IND.


2020 ◽  
Vol 8 (4) ◽  
pp. 617
Author(s):  
Tim Birr ◽  
Mario Hasler ◽  
Joseph-Alexander Verreet ◽  
Holger Klink

Fusarium head blight (FHB) is one of the most important diseases of wheat, causing yield losses and mycotoxin contamination of harvested grain. A complex of different toxigenic Fusarium species is responsible for FHB and the composition and predominance of species within the FHB complex are determined by meteorological and agronomic factors. In this study, grain of three different susceptible winter wheat cultivars from seven locations in northern Germany were analysed within a five-year survey from 2013 to 2017 by quantifying DNA amounts of different species within the Fusarium community as well as deoxynivalenol (DON) and zearalenone (ZEA) concentrations. Several Fusarium species co-occur in wheat grain samples in all years and cultivars. F. graminearum was the most prevalent species, followed by F. culmorum, F. avenaceum and F. poae, while F. tricinctum and F. langsethiae played only a subordinate role in the FHB complex in terms of DNA amounts. In all cultivars, a comparable year-specific quantitative occurrence of the six detected species and mycotoxin concentrations were found, but with decreased DNA amounts and mycotoxin concentrations in the more tolerant cultivars, especially in years with higher disease pressure. In all years, similar percentages of DNA amounts of the six species to the total Fusarium DNA amount of all detected species were found between the three cultivars for each species, with F. graminearum being the most dominant species. Differences in DNA amounts and DON and ZEA concentrations between growing seasons depended mainly on moisture factors during flowering of wheat, while high precipitation and relative humidity were the crucial meteorological factors for infection of wheat grain by Fusarium. Highly positive correlations were found between the meteorological variables precipitation and relative humidity and DNA amounts of F. graminearum, DON and ZEA concentrations during flowering, whereas the corresponding correlations were much weaker several days before (heading) and after flowering (early and late milk stage).


2008 ◽  
Vol 98 (9) ◽  
pp. 999-1011 ◽  
Author(s):  
P. A. Paul ◽  
P. E. Lipps ◽  
D. E. Hershman ◽  
M. P. McMullen ◽  
M. A. Draper ◽  
...  

The effects of propiconazole, prothioconazole, tebuconazole, metconazole, and prothioconazole+tebuconazole (as a tank mix or a formulated premix) on the control of Fusarium head blight index (IND; field or plot-level disease severity) and deoxynivalenol (DON) in wheat were determined. A multivariate random-effects meta-analytical model was fitted to the log-transformed treatment means from over 100 uniform fungicide studies across 11 years and 14 states, and the mean log ratio (relative to the untreated check or tebuconazole mean) was determined as the overall effect size for quantifying fungicide efficacy. Mean log ratios were then transformed to estimate mean percent reduction in IND and DON relative to the untreated check (percent control: [Formula: see text]IND and [Formula: see text]DON) and relative to tebuconazole. All fungicides led to a significant reduction in IND and DON (P < 0.001), although there was substantial between-study variability. Prothioconazole+tebuconazole was the most effective fungicide for IND, with a [Formula: see text]IND of 52%, followed by metconazole (50%), prothioconazole (48%), tebuconazole (40%), and propiconazole (32%). For DON, metconazole was the most effective treatment, with a [Formula: see text]DON of 45%; prothioconazole+tebuconazole and prothioconazole showed similar efficacy, with [Formula: see text]DON values of 42 and 43%, respectively; tebuconazole and propiconazole were the least effective, with [Formula: see text]DON values of 23 and 12%, respectively. All fungicides, with the exception of propiconazole, were significantly more effective than tebuconazole for control of both IND and DON (P < 0.001). Relative to tebuconazole, prothioconazole, metconazole, and tebuconzole+prothioconzole reduced disease index a further 14 to 20% and DON a further 25 to 29%. In general, fungicide efficacy was significantly higher for spring wheat than for soft winter wheat studies; depending on the fungicide, the difference in percent control between spring and soft winter wheat was 5 to 20% for [Formula: see text]IND and 7 to 16% for [Formula: see text]DON. Based on the mean log ratios and between-study variances, the probability that IND or DON in a treated plot from a randomly selected study was lower than that in the check by a fixed margin was determined, which confirmed the superior efficacy of prothioconazole, metconazole, and tebuconzole+prothioconzole for Fusarium head blight disease and toxin control.


2011 ◽  
Vol 64 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Skaidre Suproniene ◽  
Audrone Mankeviciene ◽  
Irena Gaurilcikiene

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 Forestry (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 + tebuconazole (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 identified in wheat grain, F. poae was prevalent.


2008 ◽  
Vol 43 (No. 1) ◽  
pp. 16-31 ◽  
Author(s):  
V. Šíp ◽  
J. Chrpová ◽  
L. Leišová ◽  
S. Sýkorová ◽  
L. Kučera ◽  
...  

Reactions to artificial infection with <i>Fusarium culmorum</i> and (metconazole- or tebuconazole-based) fungicides were studied in nine winter wheat cultivars that were evaluated in field experiments at the location Prague-Ruzyne for four years (2001&minus;2004) for deoxynivalenol (DON) content in grain, pathogen DNA content (Ct) by real-time quantitative PCR, percentage of Fusarium damaged grains (FDG), symptom scores and reductions in grain yield components. All examined traits were highly affected by conditions of experimental years and interactions with cultivars and treatments. Moderately resistant cultivars Arina and Petrus were included in the first homogeneous group in all traits, including the pathogen DNA content. To predict cultivar resistance to Fusarium head blight and accumulation of DON, the examination of the percentage of FDG in different environments appeared to be useful from practical aspects. The pathogen DNA content was significantly related to the content of DON under different conditions, however, the correlation coefficients ranged between 0.42 and 0.92. Different levels of DON could be detected at similar pathogen contents. The higher colonization of grain by the fungus was mostly connected with a strongly reduced amount of DON per pathogen unit (DON/Ct ratio). The fungicide treatment had a significant effect on a reduction in all traits except DON/Ct, but the effects on different traits were not often proportional and they were highly variable in the particular years (range 10&minus;69%) and cultivars (range < 0&minus;60%). While the application of fungicide caused a reduction in DON content in all cultivars, an increase in pathogen content after the application of fungicides was not exceptional. The low fungicide effect on a reduction in pathogen content was connected with higher temperatures (temperature extremes) in a 30-day period of disease development. The efficacy of fungicide treatment for DON was low at high pathogen content and late heading. The use of the collected data to improve control measures is discussed.


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