Rainfastness of Prothioconazole + Tebuconazole for Fusarium Head Blight and Deoxynivalenol Management in Soft Red Winter Wheat

Fungicides are most warranted for control of Fusarium head blight (FHB), a disease of wheat caused by the fungal pathogen Fusarium graminearum, when wet, rainy conditions occur during anthesis. However, it is unclear whether rainfall directly following application affects fungicide efficacy against FHB and its associated toxin, deoxynivalenol (DON). The objective of this study was to determine the rainfastness of the fungicide tebuconazole + prothioconazole and the residual life of tebuconazole when applied to wheat spikes at anthesis in combination with the nonionic surfactant Induce. Three field experiments were conducted during 2012 and 2013 in Wooster, OH. Simulated rainfall of a fixed intensity and duration was applied to separate plots at five different times after the fungicide treatment (0, 60, 105, 150, or 195 min). Spike samples were collected at 4-day intervals after fungicide application and assayed for tebuconazole residue. A similar set of greenhouse experiments was conducted using six post-fungicide-application rainfall timing treatments (0, 15, 30, 60, 120, or 180 min). All experiments were inoculated at anthesis with spores of F. graminearum, and FHB index (IND) and DON were quantified. In four of the five experiments, all fungicide-treated experimental units (EUs) had significantly lower mean IND and DON than the untreated check, regardless of rainfall treatment. Among rainfall treatments, EUs that received the earliest rains after fungicide application tended to have the highest numerical mean IND and DON, but were generally not significantly different from EUs that received later rain or fungicide without rain. In both years, fungicide residue on wheat spikes decreased rapidly with time after application, but the rate of reduction varied somewhat between years, with a half-life of 6 to 9 days. Rainfall treatment did not have a significant effect on the rate of residue reduction or the level of residue at a fixed sampling time after fungicide application. In this study, tebuconazole + prothioconazole mixed with a nonionic surfactant was fairly rainfast for a fixed set of rainfall characteristics, and tebuconazole residue did not persist very long after application on wheat spikes.

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Efficacy of Fungicide Applications During and After Anthesis Against Fusarium Head Blight and Deoxynivalenol in Soft Red Winter Wheat

Plant Disease ◽

10.1094/pdis-01-14-0091-re ◽

2014 ◽

Vol 98 (10) ◽

pp. 1387-1397 ◽

Cited By ~ 47

Author(s):

D. L. D'Angelo ◽

C. A. Bradley ◽

K. A. Ames ◽

K. T. Willyerd ◽

L. V. Madden ◽

...

Keyword(s):

Winter Wheat ◽

Fusarium Head Blight ◽

Field Experiments ◽

The Other ◽

Square Root ◽

Head Blight ◽

Soft Red Winter Wheat ◽

Untreated Check ◽

Red Winter Wheat ◽

Days After Anthesis

Seven field experiments were conducted in Ohio and Illinois between 2011 and 2013 to evaluate postanthesis applications of prothioconazole + tebuconazole and metconazole for Fusarium head blight and deoxynivalenol (DON) control in soft red winter wheat. Treatments consisted of an untreated check and fungicide applications made at early anthesis (A), 2 (A+2), 4 (A+4), 5 (A+5), or 6 (A+6) days after anthesis. Six of the seven experiments were augmented with artificial Fusarium graminearum inoculum, and the other was naturally infected. FHB index (IND), Fusarium damaged kernels (FDK), and DON concentration of grain were quantified. All application timings led to significantly lower mean arcsine-square-root-transformed IND and FDK (arcIND and arcFDK) and log-transformed (logDON) than in the untreated check; however, arcIND, arcFDK, and logDON for the postanthesis applications were generally not significantly different from those for the anthesis applications. Relative to the check, A+2 resulted in the highest percent control for both IND and DON, 69 and 54%, respectively, followed by A+4 (62 and 52%), A+6 (62 and 48%), and A (56 and 50%). A+2 and A+6 significantly reduced IND by 30 and 14%, respectively, relative to the anthesis application. Postanthesis applications did not, however, reduce DON relative to the anthesis application. These results suggest that applications made up to 6 days following anthesis may be just as effective as, and sometimes more effective than, anthesis applications at reducing FHB and DON.

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Effects of Integrating Cultivar Resistance and Fungicide Application on Fusarium Head Blight and Deoxynivalenol in Winter Wheat

Plant Disease ◽

10.1094/pdis-07-10-0495 ◽

2011 ◽

Vol 95 (5) ◽

pp. 554-560 ◽

Cited By ~ 69

Author(s):

Stephen N. Wegulo ◽

William W. Bockus ◽

John Hernandez Nopsa ◽

Erick D. De Wolf ◽

Kent M. Eskridge ◽

...

Keyword(s):

Winter Wheat ◽

Fusarium Head Blight ◽

Field Experiments ◽

Economic Losses ◽

Cultivar Resistance ◽

Head Blight ◽

Resistant Cultivars ◽

Fungicide Application ◽

Fungicide Efficacy ◽

Moderately Resistant

Fusarium head blight (FHB) or scab, incited by Fusarium graminearum, can cause significant economic losses in small grain production. Five field experiments were conducted from 2007 to 2009 to determine the effects on FHB and the associated mycotoxin deoxynivalenol (DON) of integrating winter wheat cultivar resistance and fungicide application. Other variables measured were yield and the percentage of Fusarium-damaged kernels (FDK). The fungicides prothioconazole + tebuconazole (formulated as Prosaro 421 SC) were applied at the rate of 0.475 liters/ha, or not applied, to three cultivars (experiments 1 to 3) or six cultivars (experiments 4 and 5) differing in their levels of resistance to FHB and DON accumulation. The effect of cultivar on FHB index was highly significant (P < 0.0001) in all five experiments. Under the highest FHB intensity and no fungicide application, the moderately resistant cultivars Harry, Heyne, Roane, and Truman had less severe FHB than the susceptible cultivars 2137, Jagalene, Overley, and Tomahawk (indices of 30 to 46% and 78 to 99%, respectively). Percent fungicide efficacy in reducing index and DON was greater in moderately resistant than in susceptible cultivars. Yield was negatively correlated with index, with FDK, and with DON, whereas index was positively correlated with FDK and with DON, and FDK and DON were positively correlated. Correlation between index and DON, index and FDK, and FDK and DON was stronger in susceptible than in moderately resistant cultivars, whereas the negative correlation between yield and FDK and yield and DON was stronger in moderately resistant than in susceptible cultivars. Overall, the strongest correlation was between index and DON (0.74 ≤ R ≤ 0.88, P ≤ 0.05). The results from this study indicate that fungicide efficacy in reducing FHB and DON was greater in moderately resistant cultivars than in susceptible ones. This shows that integrating cultivar resistance with fungicide application can be an effective strategy for management of FHB and DON in winter wheat.

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Weather requirements and rain forecast to time fungicide application for Fusarium head blight control in wheat

Summa Phytopathologica ◽

10.1590/s0100-54052013000400003 ◽

2013 ◽

Vol 39 (4) ◽

pp. 248-251 ◽

Cited By ~ 2

Author(s):

Ricardo Brustolin ◽

Sandra Maria Zoldan ◽

Erlei Melo Reis ◽

Tiago Zanatta ◽

Marcelo Carmona

Keyword(s):

Fusarium Head Blight ◽

Field Experiments ◽

Head Blight ◽

Rainfall Events ◽

Fungicide Application ◽

Weather Model ◽

Disease Occurrence ◽

Sowing Dates ◽

Initial Symptoms ◽

Two Factors

The aim of this study was to determine the minimum conditions of wetness duration and mean temperature required for Fusarium head blight infection in wheat. The weather model developed by Zoldan (2008) was tested in field experiments for two wheat cultivars grown in 2005 (five sowing dates) and 2006 (six sowing dates) in 10 m² plots with three replicates. The disease was assessed according to head incidence (HI), spikelet incidence (SI), and the interaction between these two methods was called head blight severity (HBS). Starting at the beginning of anthesis, air temperature and head wetness duration were daily recorded with an automatic weather station. With the combination of these two factors, a weather favorability table was built for the disease occurrence. Starting on the day of flowering beginning (1 - 5% fully exserted anthers), the sum of daily values for infection favorability (SDVIF) was calculated by means of a computer program, according to Zoldan (2008) table. The initial symptoms of the disease were observed at 3.7% spikelet incidence, corresponding to 2.6 SVDFI. The infection occurs in wheat due to rainfall which results in spike wetting of > 61.4 h duration. Rainfall events forecast can help time fungicide application to control FHB. The name of this alert system is proposed as UPF-scab alert.

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Effect of fungicide application to control Fusarium head blight and 20 Fusarium and Alternaria mycotoxins in winter wheat (Triticum aestivum L.)

World Mycotoxin Journal ◽

10.3920/wmj2014.1814 ◽

2015 ◽

Vol 8 (4) ◽

pp. 499-510 ◽

Cited By ~ 19

Author(s):

V. Scarpino ◽

A. Reyneri ◽

M. Sulyok ◽

R. Krska ◽

M. Blandino

Keyword(s):

Winter Wheat ◽

Fusarium Head Blight ◽

Field Experiments ◽

Fusaric Acid ◽

Growing Season ◽

Fungal Metabolites ◽

Head Blight ◽

Fungicide Application ◽

Cereal Grain ◽

Disease Pressure

Azole fungicides have been reported to be the most effective active substances in the control of Fusarium Head Blight (FHB) and in the reduction of the main mycotoxins that occur in cereal grain, such as deoxynivalenol (DON). Four field experiments have been conducted in North West Italy, over a period of 2 growing seasons, in order to evaluate the effect of azole fungicide (prothioconazole) applications on the prevalence of emerging mycotoxins in common winter wheat under naturally-infected field conditions. Wheat samples have been analysed by means of a dilute-and-shoot multi-mycotoxin LC-MS/MS method. Twenty fungal metabolites were detected: enniatins, aurofusarin, moniliformin, equisetin, DON, deoxynivalenol-3-glucoside, culmorin, bikaverin, beauvericin, fumonisins, fusaric acid, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, zearalenone, decalonectrin, butenolide, tentoxin, alternariol and alternariol methyl ether. The most abundant fungal metabolites were DON and culmorin, with an average contamination in the untreated control of 1,360 μg/kg and 875 μg/kg, respectively, in the growing season with the highest disease pressure (2011-2012). On average, the results have shown that the fungicide application significantly reduced the enniatins (from 127 μg/kg to 46 μg/kg), aurofusarin (from 62 μg/kg to 21 μg/kg), moniliformin (from 32 μg/kg to 16 μg/kg), tentoxin (from 5.2 μg/kg to 2.5 μg/kg) and equisetin (from 0.72 μg/kg to 0.06 μg/kg) contents in all the experiments. However, DON, deoxynivalenol-3-glucoside and culmorin were only significantly reduced in the growing season with the highest disease pressure. The other fungal metabolites were mainly found in traces in the untreated plots. These results, which have been obtained in different environmental and agronomic conditions, have underlined for the first time that the fungicide usually applied to control the FHB and DON content, also consistently reduces the main emerging mycotoxins of winter wheat in temperate areas.

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Meta-Analysis of the Effects of Triazole-Based Fungicides on Wheat Yield and Test Weight as Influenced by Fusarium Head Blight Intensity

Phytopathology ◽

10.1094/phyto-100-2-0160 ◽

2010 ◽

Vol 100 (2) ◽

pp. 160-171 ◽

Cited By ~ 69

Author(s):

P. A. Paul ◽

M. P. McMullen ◽

D. E. Hershman ◽

L. V. Madden

Keyword(s):

Winter Wheat ◽

Fusarium Head Blight ◽

Wheat Yield ◽

Test Weight ◽

Response To Treatment ◽

Yield Response ◽

Head Blight ◽

Yield Increase ◽

Soft Red Winter Wheat ◽

Red Winter Wheat

Multivariate random-effects meta-analyses were conducted on 12 years of data from 14 U.S. states to determine the mean yield and test-weight responses of wheat to treatment with propiconazole, prothioconazole, tebuconazole, metconazole, and prothioconazole+tebuconazole. All fungicides led to a significant increase in mean yield and test weight relative to the check (D; P < 0.001). Metconazole resulted in the highest overall yield increase, with a D of 450 kg/ha, followed by prothioconazole+tebuconazole (444.5 kg/ha), prothioconazole (419.1 kg/ha), tebuconazole (272.6 kg/ha), and propiconazole (199.6 kg/ha). Metconazole, prothioconazole+tebuconazole, and prothioconazole also resulted in the highest increases in test weight, with D values of 17.4 to 19.4 kg/m3, respectively. On a relative scale, the best three fungicides resulted in an overall 13.8 to 15.0% increase in yield but only a 2.5 to 2.8% increase in test weight. Except for prothioconazole+tebuconazole, wheat type significantly affected the yield response to treatment; depending on the fungicide, D was 110.0 to 163.7 kg/ha higher in spring than in soft-red winter wheat. Fusarium head blight (FHB) disease index (field or plot-level severity) in the untreated check plots, a measure of the risk of disease development in a study, had a significant effect on the yield response to treatment, in that D increased with increasing FHB index. The probability was estimated that fungicide treatment in a randomly selected study will result in a positive yield increase (p+) and increases of at least 250 and 500 kg/ha (p250 and p500, respectively). For the three most effective fungicide treatments (metconazole, prothioconazole+tebuconazole, and prothioconazole) at the higher selected FHB index, p+ was very large (e.g., ≥0.99 for both wheat types) but p500 was considerably lower (e.g., 0.78 to 0.92 for spring and 0.54 to 0.68 for soft-red winter wheat); at the lower FHB index, p500 for the same three fungicides was 0.34 to 0.36 for spring and only 0.09 to 0.23 for soft-red winter wheat.

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The impact of cultivar resistance and fungicide treatment on mycotoxin content in grain and yield losses caused by Fusarium head blight in wheat

Czech Journal of Genetics and Plant Breeding ◽

10.17221/93/2009-cjgpb ◽

2010 ◽

Vol 46 (No. 1) ◽

pp. 21-26 ◽

Cited By ~ 10

Author(s):

V. Šíp ◽

J. Chrpová ◽

O. Veškrna ◽

L. Bobková

Keyword(s):

Grain Yield ◽

Fusarium Head Blight ◽

Field Experiments ◽

Yield Loss ◽

Joint Effect ◽

Yield Losses ◽

Cultivar Resistance ◽

Head Blight ◽

Fungicide Treatment ◽

The Impact

Reactions to artificial infection with Fusarium graminearum isolates and a new fungicide Swing Top were studied in nine winter wheat cultivars evaluated in field experiments at two sites for three years for expression of symptoms, deoxynivalenol (DON) content in grain and grain yield. The results demonstrate a pronounced and relatively stable effect of cultivar resistance on reducing head blight, grain yield losses and contamination of grain by the mycotoxin DON. It is advantageous that the moderate level of resistance to Fusarium head blight (FHB) was detected also in two commonly grown Czech cultivars Sakura and Simila. Average fungicide efficacy for DON was 49.5% and 63.9% for a reduction in yield loss, however, it was found highly variable in different years and sites. The joint effect of cultivar resistance and fungicide treatment was 86.5% for DON and even 95.4% for reducing the yield loss. A very high risk was documented for susceptible cultivars and also the effects of medium responsive cultivars were found to be highly variable in different environments and therefore not guaranteeing sufficient protection against FHB under different conditions.

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Impact of the biofungicide tetramycin on the development of Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat

World Mycotoxin Journal ◽

10.3920/wmj2019.2494 ◽

2020 ◽

Vol 13 (2) ◽

pp. 235-246

Author(s):

W.Q. Shi ◽

L.B. Xiang ◽

D.Z. Yu ◽

S.J. Gong ◽

L.J. Yang

Keyword(s):

Fusarium Head Blight ◽

Fusarium Graminearum ◽

Spore Germination ◽

Field Experiments ◽

Synergistic Effects ◽

Field Trials ◽

Head Blight ◽

Mycelium Growth ◽

Key Aspects

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.

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