Gesunde Pflanzen (2004) 56, 201-207

D. Heibertshausen and A. Kortekamp (2004)
Infektionszyklus und biologische Bekämpfung von Podosphaera xanthii, dem Echten Mehltau der Ringelblume (Calendula officinalis)
[Infection cycle and biological control of Podosphaera xanthii, the powdery mildew of marigold (Calendula officinalis)]
Gesunde Pflanzen 56 (7-8), 201-207
Abstract: Marigold (Calendula officinalis L.) is an important medical plant that is not only used in medicine but also in food technology and for industrial purposes. An infection with Podosphaera xanthii Castagne, the causal agent of powdery mildew, leads to a drastic reduction in yield and quality in organic farming. Therefore, the infection cycle of P. xanthii was first investigated with the aid of microscopical techniques. Then the efficiancy of several plant strengtheners and two fungicides in controlling powdery mildew was tested. The application of Azoxystrobin (Fungisan^®, only tested in the greenhouse) or sulfur inhibited an infection of Calendula with P. xanthii and also its spread in the field. The application of plant strengtheners led only in the case of an Reynoutria sachalinensis extract (Milsana^®) to a reduction of disease severity, whereas other plant strengtheners on the basis of lecithin (BioBlatt Mehltaumittel), silicates (Wasserglas, Hornkiesel), sodium bicarbonate (Steinhauer's Mehltauschreck) or plant oils (TRF-FU-08^®) didn't the disease incidence and also fungal spread in the field.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: German)
Link to article at publishers website
Database assignments for author(s): Andreas Kortekamp

Research topic(s) for pests/diseases/weeds:
control - general
damage/losses/economics

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Podosphaera xanthii	Marigold (Calendula officinalis)	Germany