Effects of fungicide chemical class, fungicide application timing, and environment on Fusarium head blight in winter wheat

2020 ◽  
Vol 158 (3) ◽  
pp. 667-679
Author(s):  
Carlos Bolanos-Carriel ◽  
Stephen N. Wegulo ◽  
P. Stephen Baenziger ◽  
Deanna Funnell-Harris ◽  
Heather E. Hallen-Adams ◽  
...  
Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 554-560 ◽  
Author(s):  
Stephen N. Wegulo ◽  
William W. Bockus ◽  
John Hernandez Nopsa ◽  
Erick D. De Wolf ◽  
Kent M. Eskridge ◽  
...  

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.


2015 ◽  
Vol 8 (4) ◽  
pp. 499-510 ◽  
Author(s):  
V. Scarpino ◽  
A. Reyneri ◽  
M. Sulyok ◽  
R. Krska ◽  
M. Blandino

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.


Plant Disease ◽  
2012 ◽  
Vol 96 (6) ◽  
pp. 845-851 ◽  
Author(s):  
Megumi Yoshida ◽  
Takashi Nakajima ◽  
Kenta Tomimura ◽  
Fumihiko Suzuki ◽  
Michiyoshi Arai ◽  
...  

Fungicide application to control Fusarium head blight (FHB) and accompanying mycotoxin contamination in wheat is generally performed at anthesis because wheat is most susceptible to FHB around this stage. In this study, we evaluated the effect of the timing of fungicide application on FHB and mycotoxin (deoxynivalenol and nivalenol) accumulation in wheat based on our previous finding that the late period of grain development (beyond 20 days after anthesis [DAA]) is important to determine the final toxin contamination level in wheat. Thiophanate-methyl fungicide was tested under artificial inoculation conditions in which moisture and inoculum spores were provided throughout the testing period. Eight treatments differing in application timing (anthesis, 10, 20, and 30 DAA) and in the number of applications (0 to 2) were tested for 2 years. The results indicated that fungicide application timing differentially affects FHB (disease) and mycotoxin concentration. Fungicide application at 20 DAA reduced mycotoxin concentration in matured grain without reducing FHB severity, whereas application at anthesis was crucial for reducing FHB. These results and our previous findings suggest that around 20 DAA (late milk stage) is a potentially critical timing for mycotoxin control in wheat.


Plant Disease ◽  
2021 ◽  
Author(s):  
Gursahib Singh ◽  
Gary Peng ◽  
Garry Hnatowich ◽  
Hadley R. Kutcher

Fusarium head blight (FHB) is one of the most important diseases of durum, spring and winter wheat in Canada. Growers rely on an integrated strategy to manage the disease, including fungicide application at the current recommendation of early to 50% anthesis (BBCH61-65). This study evaluated the effect of fungicide-application timing and seeding rates of durum wheat on FHB. Field trials were carried out from 2016 to 2018 at three locations in Saskatchewan. Eight treatments of metconazole fungicide ‘Caramba®’ were applied to durum seeded at 75 and 400 seeds m-2. The fungicide treatments consisted of a nontreated check, a treated check, and applications at BBCH59, BBCH61, BBCH65, BBCH69, BBCH73 and a dual application treatment (BBCH61 followed by BBCH73). FHB index, proportion of Fusarium-damaged kernels (%FDK), deoxynivalenol (DON), grain protein content (GPC; %), and yield were evaluated. Seeding rates influenced all parameters. The high seeding rate had a higher yield and FHB index, but lower DON and GPC than the lower seeding rate. All fungicide treatments resulted in lower FHB index, DON, and %FDK than the nontreated check. Under FHB conducive conditions, all anthesis applications from BBCH61 to BBCH69 had a similar effect on FHB index, %FDK, DON, and yield, whereas in years with low disease severity, the application at BBCH65 had lower FHB index, %FDK and DON relative to other single applications. The dual application (BBCH61+73) treatment resulted in similar FHB index levels, %FDK, and DON content as the BBCH65 application at all site-years. Our results indicate that the window of fungicide application can be extended to the end of flowering when FHB risk is high.


2021 ◽  
Vol 13 (15) ◽  
pp. 3024
Author(s):  
Huiqin Ma ◽  
Wenjiang Huang ◽  
Yingying Dong ◽  
Linyi Liu ◽  
Anting Guo

Fusarium head blight (FHB) is a major winter wheat disease in China. The accurate and timely detection of wheat FHB is vital to scientific field management. By combining three types of spectral features, namely, spectral bands (SBs), vegetation indices (VIs), and wavelet features (WFs), in this study, we explore the potential of using hyperspectral imagery obtained from an unmanned aerial vehicle (UAV), to detect wheat FHB. First, during the wheat filling period, two UAV-based hyperspectral images were acquired. SBs, VIs, and WFs that were sensitive to wheat FHB were extracted and optimized from the two images. Subsequently, a field-scale wheat FHB detection model was formulated, based on the optimal spectral feature combination of SBs, VIs, and WFs (SBs + VIs + WFs), using a support vector machine. Two commonly used data normalization algorithms were utilized before the construction of the model. The single WFs, and the spectral feature combination of optimal SBs and VIs (SBs + VIs), were respectively used to formulate models for comparison and testing. The results showed that the detection model based on the normalized SBs + VIs + WFs, using min–max normalization algorithm, achieved the highest R2 of 0.88 and the lowest RMSE of 2.68% among the three models. Our results suggest that UAV-based hyperspectral imaging technology is promising for the field-scale detection of wheat FHB. Combining traditional SBs and VIs with WFs can improve the detection accuracy of wheat FHB effectively.


2010 ◽  
Vol 100 (2) ◽  
pp. 160-171 ◽  
Author(s):  
P. A. Paul ◽  
M. P. McMullen ◽  
D. E. Hershman ◽  
L. V. Madden

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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