BioControl (2006) 51, 229-243

Nuray Özer and Nagehan Desen Köycü (2006)
The ability of plant compost leachates to control black mold (Aspergillus niger) and to induce the accumulation of antifungal compounds in onion following seed treatment
BioControl 51 (2), 229-243
Abstract: Onion seeds treated with leachates of composts prepared from alfalfa and sunflower stalks, at the dosages of 10% and 20% respectively, were inoculated with Aspergillus niger van Tieghem, causal agent of onion black mold disease. The ability of the leachates to induce the production of antifungal compounds and to control black mold were tested at seedling and set stages. Leachates from both composts were able to reduce disease incidence in sets, but not disease severity in onion seedlings. Extracts from treated seedlings and sets were fractionated by thin layer chromatography for their content of antifungal compounds. There were no significant differences between the fractions of alfalfa and sunflower compost leachates in the inhibition of the mycelium growth of A. niger, with the exception of one fraction. The presence of fluorescent pseudomonads and Pantoae agglomerans [synonym: Erwinia herbicola (Löhnis)] bacteria was determined in both leachates. The population of P. agglomerans was higher in the sunflower compost leachate compared to the alfalfa leachate. The tested strains of both bacteria were able to inhibit mycelium growth of the fungal pathogen in agar tests. This study suggests the possible role of beneficial bacteria in the induction of antifungal compounds in onion against A. niger during seedling and set stages.
(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): Nuray Özer

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aspergillus niger	Onion/garlic/leek (Allium)
Pantoea agglomerans (antagonist)	Aspergillus niger	Onion/garlic/leek (Allium)