Authors: Rob Proulx 1 and Andrew Friskop 2
1. North Dakota State University, Department of Agricultural and Biosystems Engineering, Fargo, ND
2. North Dakota State University, Department of Plant Pathology, Fargo, ND
Corresponding Author: Rob Proulx, rob.proulx@ndsu.edu
Presenting Author: Rob Proulx
Abstract
Spray application technology research conducted at North Dakota State University (NDSU) from the mid- to late-2000s informed NDSU Extension recommendations for the suppression of Fusarium head blight (FHB) with fungicides applied by air or ground. Despite the increased prevalence of large, high-clearance, self-propelled sprayers in North Dakota since that time, and concurrent advancements in spray application technology, NDSU Extension recommendations had not been updated since 2008. In the absence of contemporary NDSU research, we surveyed the literature to update recommendations for fungicide applications by ground. In this presentation, I will summarize the updated recommendations and highlight changes from the historical NDSU Extension recommendations. The most significant changes center around nozzle angle, spray quality, and water volume (i.e. droplet size). While historical recommendations were to use a single forward-facing nozzle applying a fine to medium spray quality at a water volume of 10 gallons per acre (gpa), the new recommendations are to use an asymmetrical backward- and forward-facing spray at a coarse spray quality and a water volume of 10 to 20 gpa. Changes in recommended practices are primarily due to differences in spray droplet aerodynamics when ground spraying operations are conducted at 6 miles per hour in calm wind conditions, as was the case in the 2000s era research, as opposed to the breezy conditions and elevated ground speeds common during present-day ground spraying operations in North Dakota. To close the presentation, I will discuss the lessons learned while revising the recommendations in relation to contemporary applied research on drone spraying.