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Effect of Nozzle Type and Pressure on the Efficacy of Spray Applications of the Bioherbicidal Fungus Microsphaeropsis amaranthi

Published online by Cambridge University Press:  20 January 2017

David A. Doll
Affiliation:
Department of Plant Pathology, University of California Davis, Davis, CA 95616
Paul E. Sojka
Affiliation:
School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907
Steven G. Hallett*
Affiliation:
Department of Botany & Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN 47907
*
Corresponding author's E-mail: [email protected]

Abstract

The effect of application technology on efficacy has been thoroughly investigated for sprays of chemical pesticide but not biological pesticides. This study investigates the effect of applying conidia of Microsphaeropsis amaranthi, a candidate bioherbicide for Amaranthus spp., with a range of different hydraulic nozzle tips. The nozzle tips were selected to deliver sprays with different spectra of droplet sizes deployed at different angles. We found that sprays of large droplets gave poor coverage of the target and resulted in low levels of disease severity on common waterhemp. The most effective nozzle tip tested was a hollow cone nozzle tip, such as is commonly used for the application of fungicides. This nozzle tip deployed large numbers of fine droplets that swirled within the plant canopy, provided good coverage of all plant parts, and resulted in the highest levels of disease severity, particularly on stems.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

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