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ARS Home » Crop Production and Protection » Research » Research Project #445815

Research Project: Continued Monitoring and Development of Wheat Rust and Spot Modeling Tool

Location: Crop Production and Protection

Project Number: 0500-00102-001-047-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jun 1, 2024
End Date: May 31, 2025

The objective of this project is to address six diseases of wheat that are commonly observed in the United States and will be achieved in three objectives: 1) Develop predictive models based on databases of past disease epidemics in the U.S.; 2) Quantify associations among pathogen inoculum density, disease development, and weather variables in small plot trials; and 3) Quantify associations between pathogen inoculum, disease development and weather variables in commercial fields.

To achieve objective 1, curated disease observations will be coupled with weather and cropping system data. Weather information will include ground-based weather stations maintained by a federal agency and universities, as well as georeferenced weather products maintained by the project cooperators. Preliminary models of disease risk based on historical observations of epidemics will be developed. The most useful variables will be used to develop preliminary models using linear regression, logistic regression and machine learning analytical approaches. The observations collected in replicated research plots and commercial fields will be used to evaluate model performance before public deployment (see objectives 2 and 3 below). To achieve objectives 2 and 3, small plot trials in three to five locations on university farms in South Dakota (obj. 2) and 10-15 production wheat fields (obj. 3). In the selected plots and fields, three residue blocks will be established (no residue, 40%, and 80% surface cover). In obj. 2, three different varieties of wheat will be planted based upon their susceptibility to pathogens in South Dakota. Wheat stubble will be collected at 20 equally spaced points along the “W” path (5 samples per transect) and bulked into a single composite sample per residue block. Samples will be air-dried as needed, weighed, and shipped, to the cooperator. Every 24 hours, sampled air particles will be collected and sent to the cooperator's laboratory for DNA extraction and qPCR analysis. The cooperator will develop standardized protocols to quantify DNA of each pathogen in each spore sample. Leaf spot diseases and rust will be rated visually on a weekly basis. Leaf spot diseases and rust intensity will be rated on at least 60 tillers in each field and PCR testing of symptomatic plants will be done to confirm the pathogen identification.