Cucumber: Epidemiology and Control of Mycosphaerella

This information was last updated in 2015.

From recognising symptoms through to key measures of control for Mycosphaerella, these resources will help you tackle a potentially damaging fungal disease.

Understanding Mycosphaerella

In cucumber, Mycosphaerella melonis (or Didymella bryoniae) affects stems, leaves, and flowers.

The infection leads to both visible (external) and non-visible (internal) fruit rot, resulting in significant yield loss.

On some harvesting dates, up to 50% of the fruits may be affected.

Infection is not always noticed at harvest as it can be asymptomatic or latent. However, affected fruits deteriorate quickly post-harvest, leading to customer and consumer complaints.

Action plan

There are three main opportunities to reduce the risk of the disease taking hold.

During cropping:

• Control temperature and humidity
• Make sure the crop is balanced
• Keep on top of flower and leaf removal
• Clean and disinfect knives regularly

 Between crops:

• Prevent the build-up of spores by removing old plants
• Disinfect glasshouses

 During end of season clean-ups:

• Remove all plant debris
• Cover any plant material left on site in skips or compost to prevent the spread of spores
• Thoroughly clean glasshouses and equipment
• Fix any drips or leaks in guttering

Symptoms of Mycosphaerella on cucumber

Recognising the symptoms of the disease is vital to tackling it.

Biology of Mycosphaerella

Find information on the biology and epidemiology of this disease

Hygiene measures for control of Mycosphaerella

Read about key hygiene management options which are key in the prevention and management of this disease.

Managing climate for Mycosphaerella control

Find guidance on how to manage your glasshouse climate to keep Mycosphaerella under control.

Using irrigation, pruning and harvesting to manage Mycosphaerella

Know when to use water and at what temperature to help control this disease. Pruning leaves, harvesting flowers and the right equipment for the management of the disease is also outlined.

Managing Mycosphaerella with varieties and crop protection

Cultivars that show less susceptibility to the disease and other methods, such as biocontrol, can be useful for protecting your crop.

Integrated control for the management of Mycosphaerella

The best strategy to counter the disease is currently a combination of measures. There are, however, some promising developments in the pipeline.

Authors

This information was originally authored by Aleid Dik and Martin McPherson