Botrytis

The No.1 problem in floriculture

Botrytis is a major problem

Botrytis Cinerea causes waste and substantial financial losses and is a limiting factor in storage, shipment and vase life of cut flowers and foliage.

Infections with Botrytis appear as tan-coloured spots or flecks. Flowers are at risk at any stage of the process as the spores of Botrytis, which cannot be detected by the human eye, are everywhere in the ambient air.

Complex and chronic

Botrytis is a complex and chronic disease, not only in humid growing regions of the world but in the entire supply chain. Spores of Botrytis are invisible and present anywhere and at any time. That makes it such a silent and chronic profit-killer.
Notwithstanding this complexity, there are several basic concepts that go a long way to help understand this disease and to devise a strategy to manage and control it. There are several factors that play an important role in constraining Botrytis: prevention, hygiene, genetics & selection, climate control (humidity and temperature) and anti-botrytis treatments. The complexity and number of factors explain differences among growers in the percentage of flowers showing symptoms of Botrytis after harvest.





Prevention – When you see it, it’s too late

Flowers and leaves with visible marks of Botrytis cannot be cured or ‘revived’. At most the infection can be constrained on a certain level. When Botrytis really becomes visible, the quality and value of the flower have already been reduced. This process is irreversible. That’s why prevention as early as possible in the chain is so important.

Hygiene is key

Botrytis primarily attacks highly succulent, dead or injured tissues. This means that the conditions in the greenhouse, sorting area and cold store should be as hygienic as possible. In this respect we can learn a lot from protocols in e.g. the food processing industry: disinfect every tool, table or bucket and make sure that the working environment is disinfected daily

Climate Control – Temperature and Humidity

Research showed that the optimal conditions for development of Botrytis are 20°C and >90% relative humidity (RH). These conditions have to be avoided at any time in the supply chain of cut flowers.

This means that temperature should be proactively monitored, analyzed and controlled at every step of the supply chain. The optimal temperature to prevent Botrytis infection lays between 1°C and 4°C.

Spores of Botrytis develop rapidly on flowers and leaves in humid conditions. The infection spreads through the air and needs moisture to move. High humidity and water drops stimulate infection. At low humidity (<70% RH) Botrytis spores do not germinate. To prevent high humidity levels keep the door of cold stores closed as much as possible to prevent temperature changes and condensation on the flowers. Always keep flowers and packaging dry.