Plant Disease (2019) 103, 938-943

A.S. Grode, E. Brisco-McCann, P. Wiriyajitsonboom, M.K. Hausbeck and Z. Szendrei (2019)
Managing onion thrips can limit bacterial stalk and leaf necrosis in Michigan onion fields
Plant Disease 103 (5), 938-943
Abstract: Onion thrips (Thrips tabaci) is a major insect pest of onion and it has been identified as a likely vector of Pantoea agglomerans (bacterial stalk and leaf necrosis), a relatively new pathogen to Michigan's onion industry. Our objective was to develop an integrated insect and disease management program by examining the efficacy of bactericides and insecticides alone and in combination to limit bacterial stalk and leaf necrosis caused by P. agglomerans. We also examined the association of onion thrips and disease incidence in the field, because thrips are known to transmit this pathogen. In the pesticide trial, insecticides reduced both thrips abundance and bacterial stalk and leaf necrosis incidence whereas bactericides alone did not reduce disease severity. Positive correlations among thrips population density, numbers of thrips positive for P. agglomerans, and bacterial stalk and leaf necrosis incidence in onion fields were determined. This study suggests that onion thrips feeding can facilitate the development of bacterial stalk and leaf necrosis in Michigan's commercial onion fields, and results from the pesticide trials indicate that thrips feeding damage is positively correlated with disease incidence. Therefore, in order to reduce bacterial stalk and leaf necrosis incidence in onion, management efforts should include reducing onion thrips populations through the use of insecticides and other cultural practices.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mary K. Hausbeck, Zsofia Szendrei

Research topic(s) for pests/diseases/weeds:
transmission/dispersal of plant diseases
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Thrips tabaci	Onion/garlic/leek (Allium)	U.S.A. (NE)
	Pantoea agglomerans	Onion/garlic/leek (Allium)	U.S.A. (NE)