Heterogeneity of Fusarium Head Blight of Wheat: Multi-scale Distributions and Temporal Variation in Relation to Environment

2012 ◽  
Vol 13 (1) ◽  
pp. 30
Author(s):  
Alissa B. Kriss ◽  
Laurence V. Madden ◽  
Pierce A. Paul ◽  
Xiangming Xu
Keyword(s):  
Temporal Variation ◽  
Fusarium Head Blight ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Climate Index ◽  
Head Blight ◽  
Spatial And Temporal Scales ◽  
Multi Scale ◽  
Spatio Temporal ◽  
Serious Disease

Fusarium head blight (FHB) is a serious disease of wheat, which is highly variable at several spatial and temporal scales. Different statistical approaches were used to either quantify or partially explain this heterogeneity. First, a generalized linear mixed model was fitted to hierarchical survey data for the incidence of FHB in Ohio. Estimated variance terms indicated large and significant spatial heterogeneity among counties and among fields within counties, with substantially lower variation among sites within fields. Second, window-pane analysis was used to investigate the effects of environment on the inter-annual variation in FHB in four United States (US) states and the spatio-temporal variation across three European countries. Moisture- or wetness-related variables (e.g., average daily relative humidity) were positively associated with FHB intensity for multiple window lengths and starting times, especially for the last 2 months of the growing season. Third, cross-spectral analysis was used to determine whether there was coherency between variation in FHB in Ohio and global climatic patterns. There were significant coherencies at one or more inter-annual time scales (i.e., periods), with peaks in FHB following lows in the climate index (a reflection of a La Niña event) by about 1 year. Accepted for publication 27 April 2012. Published 23 July 2012.

scholarly journals Quantifying the Effects of Fusarium Head Blight on Grain Yield and Test Weight in Soft Red Winter Wheat

2015 ◽  
Vol 105 (3) ◽  
pp. 295-306 ◽  
Author(s):  
Jorge David Salgado ◽  
Laurence V. Madden ◽  
Pierce A. Paul
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Fusarium Head Blight ◽  
Fixed Effects ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Test Weight ◽  
Head Blight ◽  
Soft Red Winter Wheat ◽  
Red Winter Wheat

Fusarium head blight (FHB), caused by the fungus Fusarium graminearum, is known to negatively affect wheat grain yield (YLD) and test weight (TW). However, very little emphasis has been placed on formally quantifying FHB–YLD and FHB–TW relationships. Field plots of three soft red winter wheat cultivars—‘Cooper’ (susceptible to FHB), ‘Hopewell’ (susceptible), and ‘Truman’ (moderately resistant)—were grown during the 2009, 2010, 2011, and 2012 seasons, and spray inoculated with spore suspensions of F. graminearum and Parastagonospora nodorum to generate a range of FHB and Stagonospora leaf blotch (SLB) levels. FHB index (IND) and SLB were quantified as percent diseased spike and flag leaf area, respectively, and YLD (kg ha−1) and TW (kg m−3) data were collected. Using IND as a continuous covariate and cultivar (CV) and SLB as categorical fixed effects, linear mixed-model regression analyses (LMMR) were used to model the IND–YLD and IND–TW relationship and to determine whether these relationships were influenced by CV and SLB. The final models fitted to the data were of the generic form y = a + b (IND), where a (intercept) or b (slope) could also depend on other factors. LMMR analyses were also used to estimate a and b by combining the studies from these 4 years with an additional 16 experiments conducted from 2003 to 2013, and bivariate random-effects meta-analysis was used to estimate population mean b ([Formula: see text]) and a (ā) for the IND–YLD relationship. YLD and TW decreased as IND increased, with b ranging from −3.2 to −2.3 kg m−3 %−1 for TW. For the IND–YLD relationship, [Formula: see text] was −51.7 kg ha−1 %IND−1 and ā was 4,426.7 kg ha−1. Neither cultivar nor SLB affected the IND–YLD relationship but SLB affected a of the IND–TW regression lines, whereas cultivar affected b. Plots with the highest levels of SLB (based on ordinal categories for SLB) had the lowest a and Hopewell had the highest b. The level of IND at which a 50-kg m−3 reduction in TW was predicted to occur was 19, 16, and 22% for Cooper, Hopewell, and Truman, respectively. A yield loss of 1 MT ha−1 was predicted to occur at 19% IND. The rate of reduction in relative TW or YLD per unit increase in IND was between −0.39 and −0.32%−1 for TW and −1.17%−1 for YLD. Results from this study could be integrated into more general models to evaluate the economics of FHB management strategies.

scholarly journals Characterizing Heterogeneity of Disease Incidence in a Spatial Hierarchy: A Case Study from a Decade of Observations of Fusarium Head Blight of Wheat

2012 ◽  
Vol 102 (9) ◽  
pp. 867-877 ◽  
Author(s):  
A. B. Kriss ◽  
P. A. Paul ◽  
L. V. Madden
Keyword(s):  
Spatial Heterogeneity ◽  
Fusarium Head Blight ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Disease Incidence ◽  
Geographical Location ◽  
Disease Status ◽  
Link Function ◽  
Head Blight ◽  
Growing Seasons

A multilevel analysis of heterogeneity of disease incidence was conducted based on observations of Fusarium head blight (caused by Fusarium graminearum) in Ohio during the 2002–11 growing seasons. Sampling consisted of counting the number of diseased and healthy wheat spikes per 0.3 m of row at 10 sites (about 30 m apart) in a total of 67 to 159 sampled fields in 12 to 32 sampled counties per year. Incidence was then determined as the proportion of diseased spikes at each site. Spatial heterogeneity of incidence among counties, fields within counties, and sites within fields and counties was characterized by fitting a generalized linear mixed model to the data, using a complementary log-log link function, with the assumption that the disease status of spikes was binomially distributed conditional on the effects of county, field, and site. Based on the estimated variance terms, there was highly significant spatial heterogeneity among counties and among fields within counties each year; magnitude of the estimated variances was similar for counties and fields. The lowest level of heterogeneity was among sites within fields, and the site variance was either 0 or not significantly greater than 0 in 3 of the 10 years. Based on the variances, the intracluster correlation of disease status of spikes within sites indicated that spikes from the same site were somewhat more likely to share the same disease status relative to spikes from other sites, fields, or counties. The estimated best linear unbiased predictor (EBLUP) for each county was determined, showing large differences across the state in disease incidence (as represented by the link function of the estimated probability that a spike was diseased) but no consistency between years for the different counties. The effects of geographical location, corn and wheat acreage per county, and environmental conditions on the EBLUP for each county were not significant in the majority of years.

scholarly journals Efficacy and Economics of Integrating In-Field and Harvesting Strategies to Manage Fusarium Head Blight of Wheat

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1407-1421 ◽  
Author(s):  
Jorge David Salgado ◽  
Laurence V. Madden ◽  
Pierce A. Paul
Keyword(s):  
Fusarium Head Blight ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Management Program ◽  
Cash Income ◽  
Head Blight ◽  
Fungicide Treatment ◽  
Fungicide Application ◽  
Moderate Resistance ◽  
Moderately Resistant

Fusarium head blight (FHB), a fungal disease of wheat caused by Fusarium graminearum, and its associated toxins, particularly deoxynivalenol (DON), are best managed by integrating multiple strategies. Experiments were established in 2011 and 2013 to evaluate the effects of integrating cultivar resistance, fungicide application, and grain harvesting strategy on FHB index (IND; field severity), DON, grain yield (YLD), and grain test weight (TW; weight per unit volume). Plots of two moderately resistant and two susceptible cultivars were either treated with 19% tebuconazole + 19% prothioconazole or left untreated, and then inoculated with F. graminearum. IND was rated as the mean percentage of diseased spikelets per spike. Separate subsets of the plots of each cultivar–treatment combination were harvested with one of two combine harvester configuration: C1 (the default, set at a fan speed of 1,375 rpm and a shutter opening of 70 mm) and C4 (modified, with the same fan speeds but a wider shutter opening of 90 mm). YLD and TW data were collected, and grain samples were rated for percent Fusarium-damaged kernels (FDK) and tested for DON. Results from linear mixed-model analyses showed that the cultivar–treatment interaction was significant for all FHB-related responses, with the magnitude of the difference in mean arcsine-square-root-transformed IND and FDK (arcIND and arcFDK) and log-transformed DON (logDON) between treated and untreated being higher for susceptible than moderately resistant cultivars. Plots harvested with the C4 combine configuration had significantly higher mean TW than those harvested with C1. Treated plots had significantly higher YLD and TW than untreated plots, regardless of cultivar and configuration. Relative to the reference management program (untreated, susceptible cultivar, harvested with C1), the greatest percent reduction in FDK and DON and increase in YLD was observed for programs that included moderate resistance and fungicide treatment. The greatest percent increase in TW relative to the reference was observed when C4 adjusted combine setting was integrated with resistance and fungicide. Overall, the most effective management programs all included fungicide treatment, two included moderate resistance, and two included C4 combine setting. Relative to the reference management program, these programs resulted in 30 to 51% reduction in total estimated price discount, $127 to 312 ha−1 increase in gross cash income, and economic benefit of $31 to 272 ha−1, depending on the level of FHB IND (5 to 15%), grain price ($118 to 276 metric ton−1), and fungicide application cost ($40 to 96 ha−1).

scholarly journals Fusarium Head Blight Development and Deoxynivalenol Accumulation in Wheat as Influenced by Post-Anthesis Moisture Patterns

2015 ◽  
Vol 105 (2) ◽  
pp. 210-219 ◽  
Author(s):  
Kelsey F. Andersen ◽  
Laurence V. Madden ◽  
Pierce A. Paul
Keyword(s):  
Fusarium Head Blight ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Regression Line ◽  
Disease Spread ◽  
Marginal Effect ◽  
Head Blight ◽  
Critical Thresholds ◽  
Regression Slopes ◽  
Treatment Window

Mist chamber experiments were conducted to quantify and model the effects of post-anthesis moisture on Fusarium head blight (FHB) index (IND) and deoxynivalenol (DON). Four mist treatments, one daily and three intermittent, were applied during an 8-day window immediately after anthesis, plus an untreated check. All intermittent mist treatments received moisture on 4 of the 8 days, but the distribution of the supplemental moisture during the treatment window varied among the treatments. Separate sets of spikes in each treatment were either spray or point inoculated with a spore suspension of Fusarium graminearum. Based on results from linear mixed-model analyses, mist treatment had a significant effect on arcsine-square root-transformed IND (arcIND) and log-transformed DON (logDON) in spray-inoculated spikes but only a marginal effect on DON in point-inoculated spikes. The daily mist treatments (Mist1) consistently had the highest mean IND and DON but several of the 4-day intermittent mist treatments were not significantly different, particularly for point inoculations. Only Mist1 and one of the intermittent mist treatments (Mist2; 2 days of mist at the beginning and end of the treatment window) had significantly higher infection efficiency (estimated diseased spikelets per spore) than the check; however, none of the treatments increased the rate of disease spread within the spike (based on visual symptoms) relative to the check. For all treatments, there was a significant, positive linear relationship between IND and logDON, with estimated mean regression slopes (rates of logDON increase per unit increase in IND) of 0.04 and 0.02 logDON %−1 IND for the point- and spray-inoculated experiments, respectively. Mist treatment did not have a significant effect on the slope but had a significant effect on the intercept. The height of the regression line (logDON after adjusting for IND) was consistently higher for Mist2 than for Mist1 for both point- and spray-inoculated spikes. Estimated mean back-transformed DON at a fixed level of IND was 4.9 and 2.9 ppm higher for Mist2 than Mist1 in the spray- and point-inoculation experiments, respectively. Generalized linear mixed models were used to estimate the risk of IND and DON exceeding critical thresholds, showing similar results among treatments in terms of estimated probabilities. The estimated probabilities of IND ≥ 10% at 20 days after inoculation and DON ≥ 2, 5, and 10 ppm were not significantly different between Mist1 and Mist2. These results suggest that post-anthesis moisture patterns may play a role in DON exceeding critical thresholds even when FHB level are relatively low.

Evaluation of Application Timing of Miravis Ace for Control of Fusarium Head Blight in Wheat

2021 ◽  
pp. PHP-01-21-0007-
Author(s):  
Lovepreet Singh ◽  
Taylor Schulden ◽  
Jason P. Wight ◽  
Joseph Crank ◽  
Louis Thorne ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Weather Conditions ◽  
Head Blight ◽  
Flowering Stage ◽  
Technical Problems ◽  
Application Timing ◽  
Significant Control ◽  
Small Window ◽  
Three Stages ◽  
Serious Disease

Fusarium head blight (FHB) is a serious disease of wheat and barley that not only lowers yield but also contaminates the grain with associated mycotoxins such as deoxynivalenol (DON). Chemical control options for FHB and DON include application of triazole fungicides at the anthesis or flowering stage. This presents practical challenges for growers in managing FHB, as the appropriate timing window typically lasts only 3 to 4 days. If this small window is missed, due to weather conditions or technical problems, fungicide application is less effective in controlling FHB and DON. The present work was conducted over 2 years (2019 and 2020) to test the efficacy of a new fungicide (pydiflumetofen + propiconazole) from Syngenta labeled as Miravis Ace in controlling FHB and DON content at 50% head emergence (Feekes 10.3), anthesis (Feekes 10.5.1), and end of flowering (Feekes 10.5.3) stages. Prosaro 421 SC, a standard FHB control triazole fungicide, was used at all three stages for comparison with the test fungicide. Miravis Ace application at 50% head emergence provided significant control over the nontreated check for FHB incidence (2020), FHB severity (2019), and DON content (2019) with control efficacies as high as 51, 69, and 52%, respectively. However, mean control percentages relative to the check were highest with Miravis Ace at anthesis in both 2019 and 2020 for all the FHB parameters. In conclusion, 50% head emergence provides statistically significant control on FHB and DON, but anthesis was the most effective application stage for Miravis Ace.

scholarly journals Bayesian spatial and spatio-temporal approaches to modelling dengue fever: a systematic review

2018 ◽  
Vol 147 ◽  
Author(s):  
A. Aswi ◽  
S. M. Cramb ◽  
P. Moraga ◽  
K. Mengersen
Keyword(s):  
Dengue Fever ◽  
Random Effects ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Assessment Tool ◽  
Temporal Dynamics ◽  
Random Effect ◽  
Temperature And Precipitation ◽  
Generalised Linear Mixed Model ◽  
Spatio Temporal

AbstractDengue fever (DF) is one of the world's most disabling mosquito-borne diseases, with a variety of approaches available to model its spatial and temporal dynamics. This paper aims to identify and compare the different spatial and spatio-temporal Bayesian modelling methods that have been applied to DF and examine influential covariates that have been reportedly associated with the risk of DF. A systematic search was performed in December 2017, using Web of Science, Scopus, ScienceDirect, PubMed, ProQuest and Medline (via Ebscohost) electronic databases. The search was restricted to refereed journal articles published in English from January 2000 to November 2017. Thirty-one articles met the inclusion criteria. Using a modified quality assessment tool, the median quality score across studies was 14/16. The most popular Bayesian statistical approach to dengue modelling was a generalised linear mixed model with spatial random effects described by a conditional autoregressive prior. A limited number of studies included spatio-temporal random effects. Temperature and precipitation were shown to often influence the risk of dengue. Developing spatio-temporal random-effect models, considering other priors, using a dataset that covers an extended time period, and investigating other covariates would help to better understand and control DF transmission.

scholarly journals Mixed Model Association Mapping for Fusarium Head Blight Resistance in Tunisian-Derived Durum Wheat Populations

2011 ◽  
Vol 1 (3) ◽  
pp. 209-218 ◽  
Author(s):  
Farhad Ghavami ◽  
Elias M. Elias ◽  
Sujan Mamidi ◽  
Omid Ansari ◽  
Mehdi Sargolzaei ◽  
...  
Keyword(s):  
Association Mapping ◽  
Durum Wheat ◽  
Fusarium Head Blight ◽  
Mixed Model ◽  
Fusarium Head Blight Resistance ◽  
Blight Resistance ◽  
Head Blight

scholarly journals Modeling of Yield Losses and Risk Analysis of Fungicide Profitability for Managing Fusarium Head Blight in Brazilian Spring Wheat

2019 ◽  
Author(s):  
Maíra Rodrigues Duffeck ◽  
Kaique dos Santos Alves ◽  
Franklin Jackson Machado ◽  
Paul David Esker ◽  
Emerson Medeiros Del Ponte
Keyword(s):  
Fusarium Head Blight ◽  
Field Trials ◽  
Random Coefficients ◽  
Review Of Literature ◽  
Head Blight ◽  
Planting Dates ◽  
Yield Data ◽  
Population Average ◽  
Damage Coefficient ◽  
Serious Disease

AbstractFusarium head blight (FHB), caused by theFusarium graminearumspecies complex, is a serious disease of wheat in Brazil. A review of literature on fungicide efficacy for field trials evaluated in Brazil was conducted to obtain FHB-yield data and explore their relationship. Thirty-seven studies (9 years and 11 locations) met the criteria for inclusion (FHB index ≥ 5% and max-min range ≥ 4 percent points [p.p.]). Studies were group into two production situations: low (Yl≤ 3,631 kg ha−1) or high (Yh> 3,631 kg ha−1) yield, based on the median of maximum yields across trials. Population-average intercepts, but not the slopes, from fitting a random-coefficients model, differed significantly betweenYl(2,883.6 kg ha−1) andYh(4,419.5 kg ha−1). The calculated damage coefficient was 1.05 %−1and 1.60 %−1forYhandYl, respectively. A crop model simulated attainable wheat yields for 10 planting dates within each year during a 28-year period, including prior (1980-1989) and after (1990-2007) FHB resurgence. Simulated losses using disease predictions to penalize yield were in general agreement in magnitude with literature reports, for both periods. Economic analysis for scenarios of variable fungicide costs and wheat prices, and one versus two sprays of tebuconazole, showed that the probability of not-offsetting the costs was higher (> 0.75) prior to FHB resurgence than after the 1990. Our approach may be useful for designing of longlasting, yet profitable, contingency tactics to management FHB in wheat. Currently one spray of triazole fungicide during flowering is more likely a profitable decision than applying two sprays, for which there is greater uncertainty.

scholarly journals Temporal variation of soil organic carbon and total nitrogen stock and concentration along land use, species and elevation gradient of chilimo dry afromonate forest and adjacent land uses, ethiopia

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Mehari A. Tesfaye 1 ◽  
Andres Bravo Oviedo 2 ◽  
Felipe Bravo 3
Keyword(s):  
Land Use ◽  
Temporal Variation ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Soil Depth ◽  
Elevation Gradient ◽  
Native Forest ◽  
Carbon And Nitrogen ◽  
Nitrogen Stock ◽  
C And N

Forests play a vital role in the natural global carbon cycle by capturing carbon from the atmosphere through photosynthesis and converting it into forest biomass. Forests sequester and stores more carbon than any terrestrial ecosystem and act as sources as well as sinks of CO2. However, the increasing rate of deforestation and the impact of changes in land use require a critical and updated look at what is happening in the tropics. This work emphasized the temporal variation of bulk density, carbon (C) and nitrogen (N) stock and concentration in four land-use categories: natural forest, tree plantations, crop-land and degraded soil along elevation gradient and soil depth. The study was conducted in the Central Highlands of Ethiopia, where deforestation and human pressure on native forests are exacerbated and erosion has caused extensive soil loss. We hypothesized that, there is temporal variation of C and N concentrations and stocks in native forest along elevation gradient, land use type, species and soil depth. Carbon and N concentrations and stock and bulk densities in mineral soil were analysed as repeated measures in an irregular vertical space ranging from 0–10 cm, 10–30 cm, 30–50 cm and 50–100 cm, using a linear mixed model approach in two-time scale period 2012 - 2017. Double observations in 2012 and 2017, were made from the forest floor were analysed by a general linear mixed model. There is significant variation in organic carbon and nitrogen stock along elevation gradient for forest floor. Results also indicated that soil depth is more important factor than elevation gradient in native forests, though C and N concentrations and stocks diminished near human settlements. Native forest stored on average more nitrogen than bare soil, cropland and plantations, respectively. Conversion of crop and degraded land into plantations ameliorated soil degradation conditions, but species selection did not affect carbon and nitrogen stocks. Thus, appropriate forest management options should be applied in order to increase productivity and carbon sink of Chilimo dryafromontane forest and adjacent land use. Temporal monitoring and reporting of carbon stock and concentration is also important to understand the role of Chilimo dryafromonate forest in climate change mitigation and adaptation agendas.

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