A FIRST-GENERATION MODEL FOR DON PREDICTION AND INTEGRATED MANAGEMENT OF FHB AND DON
Project Number: 0500-00053-003-15
Start Date: May 13, 2009
End Date: May 12, 2013
Project # 1: (1) Advance the development of DON prediction models through better understanding of factors influencing DON accumulation and (2) Continue the development of mechanistic models for FHB/DON and refinement of empirical models.
Project #2: Experiments will be conducted in Ohio, as part of a series of uniform integrated management trials involving researchers from major wheat-growing regions in the U.S., with the goal of evaluating the efficacy of integrating multiple management strategies to reduce losses due to FHB and DON. The specific objective is to evaluate the integrated effects of fungicide, biocontrol agent, and variety resistance on FHB and DON.
Project #1: Use data generated by the integrated management trials to study the relationship of weather, inoculum and disease/DON. Evaluate data from inoculated, non-irrigated breeding nurseries in an effort to characterize weather- and crop-related factors that influence the probability of infection and DON accumulation when inoculum is not limiting. The hourly weather data associated with each location will be edited to eliminate questionable data points and specialized spreadsheet macros will be used to construct composite input variables representing different time windows relative to the time of anthesis.
Several candidate models will be developed and evaluated to predict whether DON levels in the harvested grain will be above several different thresholds (1, 2, and 4 ppm) based on summaries of weather conditions prior to and during anthesis and early grain fill. The accuracy of all developed models will be calculated in term of: 1) sensitivity, true positive proportion, fraction of true high-disease or high-DON location-years correctly predicted and 2) specificity, the true negative proportion, fraction of true low-disease or low (zero)-DON location-years correctly predicted.
Project #2: The experimental design will be a split-plot with 6 replicate blocks. In each block, there will be three whole plots, one treated with Prosaro, one treated with a biocontrol agent (Cryptococcus flavescens strain OH 182.9) and the other left untreated. Each whole plot will be subdivided into sub-plots to which six SRWW cultivars with different levels of resistance to FHB, moderately susceptible; and “Truman” and “McCormick”, moderately resistant) will be randomly assigned. A single fungicide application will be made on the time of early anthesis (Feekes GS 10.5.1) for each cultivar using a sprayer equipped with paired Twinjet or flat fan XR8001 nozzles, mounted at an angle (30o from the horizontal) forward and backward and calibrated to deliver at a rate of 20 gallons per acre. Biomass of strain OH 182.9 will be produced, quantified, and handled at NCAUR, USDA-ARS laboratories in Peoria, IL. Frozen biomass of OH 182.9 will be thawed in a refrigerator 24 hours prior to being applied and applications will be made at Feekes GS 10.5.1 at a rate of 20 gal/acre at 40 psi. FHB intensity will be assessed by examining 20 spikes at five arbitrarily selected sites in each plot at the soft dough growth stage (Feekes 11.2). At each assessment, FHB severity will be determined visually for each sub-plot, and incidence, diseased head severity, and index calculated. The presence and flag leaf severity (as a percentage) of any foliar diseases will also be determined. Plots will be harvested with a plot combine and yield and test weight determined. Grain samples from all plots will be rated to determine the percentage of Fusarium damaged kernels and subsamples will be sent to one of the USWBSI-funded DON Testing Laboratories for DON analysis.