European Journal of Plant Pathology (1996) 102, 265-275

T.D.W. James and J.C. Sutton (1996)
Biological control of botrytis leaf blight of onion by Gliocladium roseum applied as sprays and with fabric applicators
European Journal of Plant Pathology 102 (3), 265-275
Abstract: Gliocladium roseum (5×10⁶ conidia ml^-1) and chlorothalonil (Bravo 500) were compared in two field tests for effectiveness in suppressing leaf blight caused by Botrytis squamosa in cooking onions. The biological control agent and fungicide were applied with sprayers and with specially designed fabric applicators that were mounted interchangeably on an aluminium carriage with bicycle wheels. In the applicators, inoculum and fungicide gravitated from a reservoir down curtains of denim strips and onto portions of onion leaves contacted by the strips. Initial applications were timed using a leaf blight forecasting system (BOTCAST) and three or four subsequent applications were made at weekly intervals. When compared to water checks, G. roseum applied as sprays or by applicators reduced density of leaf spots by about 50-58% during middle and late stages of epidemics. The antagonist was about half as effective as chlorothalonil in suppressing density of spots, regardless of application method. The applicators delivered inoculum in similar densities to proximal and distal halves of leaves, and used at least 35% less volume of inoculum compared to the sprayers. Density of inoculum on leaves treated by applicators was about the same as in spray-treated leaves when canopies were sparse, but less when canopies were dense. It is concluded that G. roseum has good potential for controlling leaf blight sufficiently to avoid economic yield losses.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
control - general
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Botrytis squamosa	Onion/garlic/leek (Allium)
Clonostachys rosea (antagonist)	Botrytis squamosa	Onion/garlic/leek (Allium)