Location: Crop Production and Protection
Project Number: 0500-00102-001-037-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 1, 2024
End Date: May 31, 2025
Objective:
The overall objectives of this projects are to (1) Develop disease prediction models for corn diseases based on presence of initial inoculum, aerial spore density, and production and environmental factors; and (2) Validate the accuracy of disease prediction of each model.
Approach:
The project goals are conducted in two objectives: 1) Establish the association between inoculum intensity, production factors, disease development and weather in experimental plot trials; and 2) Disseminate corn disease information and management techniques through various outputs. In order to achieve objective 1, the work will focus on the following diseases: northern corn leaf blight (NCLB), gray leaf spot (GLS), southern rust (SR), Curvularia leaf spot (CLS), and Gibberella ear rot (GER). Two experimental trials will be established at the university research site to investigate associations among the disease intensity and the following factors: (1) crop residue cover; (2) genetic resistance; (3) fungicide application at VT/R1; and (4) airborne inoculum density. At each trial site, plots will be planted into blocks with high surface residue (>80% residue cover) and low (<20% residue cover) surface residue treatments. In both trials, two hybrids with different levels of resistance to GLS and SR (one moderately resistant to both diseases and the other susceptible to both). A foliar fungicide will be applied to half the plots, while no fungicide will be applied to the other half of the plots. Spore traps will be placed in the center of each field to monitor airborne inoculum density. Corn residue samples, consisting of 4-6 pieces of leaves and leaf sheaths, will be collected at 20 approximately equally spaced points along the line transect method described above (5 samples per transect) and bulked into a single composite sample per field. Samples will be air-dried as needed, weighed and sent to a cooperator for DNA extraction and qPCR analysis for pathogen identification. Disease ratings will be assessed bi-weekly. For mycotoxin assessment, grain samples will be collected at harvest and shipped to a cooperator for mycotoxin contamination analysis. In order to achieve objective 2, data collected from the trials described under objective 1 will be shared at field days throughout the growing season and workshops during the winter. Data on estimated yield losses due to disease will be contributed to a disease loss calculator. Corn disease management content for national and local websites will be developed.
