Journal of Applied Entomology (2012) 136, 234-237

P. Kehrli and N. Delabays (2012)
Controlling 'bois noir' disease on grapevine: does the timing of herbicide application affect vector emergence?
Journal of Applied Entomology 136 (3), 234-237
Abstract: Bois noir is an important grapevine yellows disease that can cause serious economical losses in European grapevine production. Hyalesthes obsoletus Signoret (Hemiptera, Cixiidae) is the principal vector of bois noir in Switzerland and stinging nettle (Urtica dioica) is its favourite host plant species in vineyards. As bois noir disease can hardly be cured and direct control measures against H. obsoletus are ineffective, viticultural control practices target stinging nettle, the actual reservoir and source of both the pathogen and its vector. Currently, it is recommended to apply herbicides against stinging nettle at the end of the season to kill developing H. obsoletus nymphs. To verify if this late period of herbicide application is justified, stinging nettle patches were treated with glyphosate in the autumn, in the spring or were left untreated as a control. Herbicide applications at both dates controlled the growth of stinging nettle very well in the subsequent summer, although the autumnal treatment was slightly more efficient. To study glyphosate's direct impact on the development of H. obsoletus nymphs, emergence traps were placed directly in the centre of treated and untreated stinging nettle patches. There was no significant difference among the three treatments in the total number of adults emerging. Thus, an aerial application of glyphosate in either spring or autumn did not inhibit the nymphs' development on the roots of stinging nettle in the soil. Our results challenge current recommendations of applying herbicides against stinging nettle at the end of the season and suggest that stinging nettle could also be controlled in spring, alike other viticultural weeds.
(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): Patrik Kehrli

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytoplasma solani	Grapevine (Vitis)	Switzerland
	Hyalesthes obsoletus	Grapevine (Vitis)	Switzerland
	Urtica dioica (weed)	Grapevine (Vitis)	Switzerland