Poster # 107 View Poster

José C. Flores Guzman ¹, Erick DeWolf ¹, Jessica Rupp Noller ¹, Rodrigo Borba Onofre ¹, Raissa Debacker Moura ^1,2, and Kelsey Andersen Onofre ¹
1. Department of Plant Pathology, Kansas State University, Manhattan, KS, USA
2. Department of Plant Sciences & Plant Pathology, Montana State University, Bozeman, MT, USA
Corresponding Author: José C. Flores Guzman, floresgu@ksu.edu and Kelsey Andersen Onofre, andersenk@ksu.edu

Flores Guzman, Jose

floresgu@ksu.edu

Abstract: Fusarium head blight (FHB), caused primarily by Fusarium graminearum, remains one of the most economically important diseases of wheat worldwide and has become an increasing concern in Kansas in recent years. Effective management requires an integrated approach, combining genetic resistance, fungicide applications at early anthesis (Feekes 10.5.1), and cultural practices. Recent studies suggest that higher seeding rates may promote more uniform flowering periods, potentially improving fungicide coverage and disease suppression under favorable conditions for FHB. Additionally, denser canopies resulting from higher plant populations may physically reduce the exposure of wheat heads to F. graminearum spores, acting as a partial barrier to infection. We hypothesize that higher seeding rates enhance the performance of fungicide applications and genetic resistance under high FHB pressure. Field experiments were conducted in five site-years, Parsons, KS (2022–2023), Manhattan and Ottawa, KS (2023-24, 2024-25) using a full factorial randomized complete block design evaluating two levels of genetic resistance (‘Green Hammer’—susceptible and ‘Zenda’—moderately resistant), three seeding rates (500,000, 1,000,000, and 1,500,000 seeds/A), and two fungicide treatments (Miravis® Ace 13.7 fl oz/A applied at Feekes 10.5.1 versus untreated). Results showed that higher seeding rates reduced FHB index and deoxynivalenol (DON) accumulation across both varieties. The combination of the moderately resistant variety, highest seeding rate, and a single fungicide application resulted in the lowest FHB index, lowest DON concentration, and highest yield. These findings highlight the potential of optimizing seeding rate as a complementary strategy to improve fungicide efficacy and strengthen integrated FHB management recommendations for Kansas wheat producers.

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