Are DMI+QoI premixes applied during flowering worth for protecting wheat yields from Fusarium head blight? A meta-analysis

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is best controlled with demethylation inhibitor (DMI) fungicides applied during flowering. However, the use of premixes of DMI and quinone outside inhibitor (QoI) fungicides to control FHB has increased in Brazil, but the individual results are inconsistent. Data on FHB severity and wheat yields measured in field experiments conducted in Brazil were gathered from both peer- and non-peer-reviewed sources published from 2000 to 2018. After applying selection criteria, 35 bibliographic sources, contributing 73 (50% from cooperative trials) trials, were identified. At least one of four DMI+QoI premixes and one tebuconazole (TEB) treatment, applied mostly twice (full-flowering and 10 days) tested in at least 14 trials and three year each, were present in a selected trial. Estimates of percent control (and respective 95%CI) by a network model ranged from 44.1% (pyraclostrobin + metconazole applied once; 32.4 - 53.7) to 64.3% (pyraclostrobin + metconazole; 58.4 - 69.3); the latter not differing from TEB (59.9%, 53.6 - 65.3). Yield response was statistically similar for pyraclostrobin + metconazole (532.1 kg/ha, 441 - 623) and trifloxystrobin + prothioconazole (494.9 kg/ha, 385 - 551), and both differed statistically from a group composed of TEB (448.2 kg/ha, 342 - 554), trifloxystrobin + TEB (468.2 kg/ha, 385 - 551), azoxystrobin + TEB (462.4 kg/ha, 366 - 558) and pyraclostrobin + metconazole applied once (413.7 kg/ha, 308 - 518). The two categories of FHB index (7% cut off) and yield (3,000 kg/ha), both in the non-treated check, did not explain the heterogeneity in the estimates. The probability of not-offsetting control costs was generally lower than 0.45 for scenarios considering two sequential sprays of the low-cost TEB or one spray of pyraclostrobin + metconazole as management choices. The envisioned enhanced economic return, solely based on yield response, from using two sprays of DMI+QoI premixes to control FHB should be seen with caution given the marginal levels of profitability.

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Are DMI+QoI Fungicide Premixes During flowering Worthwhile for Fusarium head blight Control in Wheat? A Meta-analysis

Plant Disease ◽

10.1094/pdis-09-20-2096-re ◽

2020 ◽

Author(s):

Jhonatan Barro ◽

Flávio Martins Santana ◽

Franklin Jackson Machado ◽

Maíra Rodrigues Duffeck ◽

Douglas Lau ◽

...

Keyword(s):

Fusarium Head Blight ◽

Field Experiments ◽

Meta Analysis ◽

Field Trials ◽

Yield Response ◽

Cooperative Network ◽

Head Blight ◽

Qoi Fungicides ◽

Quinone Outside Inhibitor ◽

Dmi Fungicides

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is best controlled with demethylation inhibitor (DMI) fungicides during flowering. However, the use of premixes of DMI and quinone outside inhibitor (QoI) fungicides to control FHB has increased in Brazil. Data on FHB severity and wheat yields measured in field experiments conducted in Brazil were gathered from both peer- and non-peer-reviewed sources published from 2000 to 2018. After applying selection criteria, 73 field trials from 35 bibliographic sources were identified, among which 50% of the data were obtained from cooperative network trials conducted after 2011. To be included in the analysis, a DMI+QoI premixes or tebuconazole (TEB) were tested in at least 14 trials and three years. Four premixes met the criteria. Estimates of percent control (and respective 95% confidence interval) by a network model fitted to the log of the treatment means ranged from 44.1% (pyraclostrobin + metconazole applied once; 32.4 to 53.7) to 64.3% (pyraclostrobin + metconazole; 58.4 to 69.3); the latter not differing from TEB (59.9%, 53.6 to 65.3). Yield response was statistically similar for pyraclostrobin + metconazole (532.1 kg/ha, 441 to 623) and trifloxystrobin + prothioconazole (494.9 kg/ha, 385 to 551), and both differed statistically from a group composed of TEB (448.2 kg/ha, 342 to 554), trifloxystrobin + TEB (468.2 kg/ha, 385 to 551), azoxystrobin + TEB (462.4 kg/ha, 366 to 558) and pyraclostrobin + metconazole applied once (413.7 kg/ha, 308 to 518). The two categories of FHB index (7% cut off) and yield (3,000 kg/ha cut off), both in the non-treated check, did not explain the heterogeneity in the estimates. Two sequential sprays of TEB or one spray of pyraclostrobin + metconazole as management choices are likely more profitable than DIM+QoI premixes sprayed twice during flowering considering only the fungicide effects on yield.

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The Effect of Fhb1 and Fhb5 Quantitative Trait Loci in Hard Red Spring Wheat Does Not Depend on Fungicide Use for Managing Fusarium Head Blight in Wheat

Plant Disease ◽

10.1094/pdis-09-18-1559-re ◽

2019 ◽

Vol 103 (8) ◽

pp. 1850-1857

Author(s):

Gurcharn S. Brar ◽

Garry Hnatowich ◽

Gary Peng ◽

Pierre J. Hucl ◽

Hadley R. Kutcher

Keyword(s):

Quantitative Trait Loci ◽

Fusarium Head Blight ◽

Spring Wheat ◽

Quantitative Trait ◽

Field Experiments ◽

Head Blight ◽

Hard Red Spring Wheat ◽

Full Flowering ◽

Trait Loci ◽

The Individual

Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most damaging diseases that affect wheat in Canada. The disease is best managed by integrating host resistance and fungicides, mainly demethylation inhibitors. Research has shown that the effect of fungicides may be dependent on the level of resistance of the cultivar. However, whether the performance of genotypes carrying specific Sumai 3-derived major FHB quantitative trait loci is dependent on fungicide application has not been explored. In our study, the performance of near-isogenic lines (NILs; <1.0% genome/alleles from the resistance donor), carrying Fhb1 and Fhb5 in a hard red spring wheat cultivar CDC Go background compared with a moderately susceptible (MS) genotype, was evaluated with and without one application of metconazole during full flowering. Field experiments were conducted at five site-years in Saskatchewan, Canada, between 2016 and 2017. In both the individual and combined analysis (all trials), we found that the effect of NILs and metconazole in suppressing FHB symptoms and deoxynivalenol (DON) accumulation in the grain was additive. FHB severity was generally low and fungicide efficacy levels, relative to the untreated control, were increased in the MS cultivar than in the NILs carrying Fhb1 and Fhb5, which were least affected by the disease. The results confirm the importance of integrating fungicides with cultivar resistance to reduce FHB and DON, regardless of the presence of those well-characterized resistant genes.

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Low-Cost Spore Traps: An Efficient Tool to Manage Fusarium Head Blight through Improved Cropping Systems

Agronomy ◽

10.3390/agronomy11050987 ◽

2021 ◽

Vol 11 (5) ◽

pp. 987

Author(s):

Hans-Rudolf Forrer ◽

Annegret Pflugfelder ◽

Tomke Musa ◽

Susanne Vogelgsang

Keyword(s):

Fusarium Head Blight ◽

Field Experiments ◽

Cropping Systems ◽

Low Cost ◽

Infected Plant ◽

Petri Dish ◽

Head Blight ◽

Host Genotype ◽

Spore Trap ◽

Power Sources

Fusarium head blight (FHB) is a devastating disease of wheat. Worldwide, Fusarium graminearum is the most dominant FHB-causing species. Its most common toxin, deoxynivalenol (DON), impairs food and feed safety and has an enormous economic impact. Agronomic factors such as crop rotation, soil management and host genotype strongly influence the occurrence of F. graminearum. Infected plant debris from previous crops, on which perithecia and ascospores develop, represent the main source for FHB, and hence, improved cropping systems aim to reduce this inoculum to decrease the infection risk. The best measure to evaluate the disease pressure is spore traps that detect deposited airborne ascospores. Commercial spore traps are expensive and require power sources, thus, they are not suitable for investigations in field experiments with different treatments. In consequence, we developed spore traps containing a Petri dish with Fusarium-selective agar, protected by aluminum dishes and attached on a wooden board. We compared the data of our low-cost trap with those of a commercial high-throughput jet sampler and obtained equivalent results. In field experiments to compare cropping systems, we observed a high correlation between the DON content in wheat grains and the number of colonies from deposited spores. Our spore trap proved to be a highly valuable tool to not only study FHB epidemiology but also to identify innovative cropping systems with a lower risk for FHB and DON contamination.

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Meta-Analysis of the Effects of QoI and DMI Fungicide Combinations on Fusarium Head Blight and Deoxynivalenol in Wheat

Plant Disease ◽

10.1094/pdis-02-18-0211-re ◽

2018 ◽

Vol 102 (12) ◽

pp. 2602-2615 ◽

Cited By ~ 6

Author(s):

P. A. Paul ◽

C. A. Bradley ◽

L. V. Madden ◽

F. Dalla Lana ◽

G. C. Bergstrom ◽

...

Keyword(s):

Fusarium Head Blight ◽

Meta Analysis ◽

Field Trials ◽

Analytical Models ◽

Head Blight ◽

Quinone Outside Inhibitor ◽

Negative Effect ◽

Meta Analyses ◽

Demethylation Inhibitor ◽

Do So

Field trials were conducted in 17 U.S. states to evaluate the effects of quinone outside inhibitor (QoI) and demethylation inhibitor (DMI) fungicide programs on Fusarium head blight index (IND) and deoxynivalenol (DON) toxin in wheat. Four DMI-only treatments applied at Feekes 10.5.1, five QoI-only treatments applied between Feekes 9 or Feekes 10.5, three QoI+DMI mixtures applied at Feekes 10.5, and three treatments consisting of a QoI at Feekes 9 followed by a DMI at Feekes 10.5.1 were evaluated. Network meta-analytical models were fitted to log-transformed mean IND and DON data and estimated contrasts of log means were used to obtain estimates of mean percent controls relative to the nontreated check as measures of efficacy. Results from the meta-analyses were also used to assess the risk of DON increase in future trials. DMI at Feekes 10.5.1 were the most effective programs against IND and DON and the least likely to increase DON in future trials. QoI-only programs increased mean DON over the nontreated checks and were the most likely to do so in future trials, particularly when applied at Feekes 10.5. The effects of QoI+DMI combinations depended on the active ingredients and whether the two were applied as a mixture at heading or sequentially. Following a Feekes 9 QoI application with a Feekes 10.5.1 application of a DMI reduced the negative effect of the QoI on DON but was not sufficient to achieve the efficacy of the Feekes 10.5.1 DMI-only treatments. Our results suggest that one must be prudent when using QoI treatments under moderate to high risk of FHB, particularly where the QoI is used without an effective DMI applied in combination or in sequence.

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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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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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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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