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Powdery Mildew
Pests and Diseases Nutrients plant health

Posted By: Plant Magic

Common Plant Diseases and How to Fix Them: Powdery Mildew

One of the most common plant diseases, powdery mildew is easily recognisable. These fungal diseases remove plants’ nutrients and cause them to become weaker and to bloom less. With hydroponic plants it’s vital to keep the environment carefully controlled and clean, as powdery mildew thrives with high relative humidity and warmth.

There are narrow host ranges infected by powdery mildew, and each species infects different plants. During winter, this disease tends to stay as a dormant infection on green tissues or on fallen leaves as resting structures until the following spring, when they release spores.

Susceptible plants are ornamental garden plants and common edible plants such as apples, grapes, cucumbers, cereal crops, roses, and many more.


What is Powdery Mildew?

These fungi produce microscopic, airborne spores for dispersal, which are released from the fungal growth on plants. The spores can infect plants even in drier conditions; unlike most fungal pathogens, mildew spores have an unusually high content of water. This tends to associate this disease with water stress.

Powdery mildew spores have feeding structures that are sent to the surface cells in most species, but a few species have their fungal growth deeper in the plants’ tissues. This group of related fungi is easily recognisable by the main symptom which is a white and dusty coating on stems, leaves, and flowers of plants. Other symptoms of powdery mildew are:

  • In Rhamnus plants, for example, the early stages of a powdery mildew infection cause a strong colour change to dark brown in the affected areas.
  • Affected plant tissues often become distorted or stunted, which is easily seen in plants affected by the rose powdery mildew.
  • The infected undersurface of rhododendron leaves, for example, can be difficult to spot, as the fungal growth is has a light colour.

Rhododendron Plant

What Causes Powdery Mildew Infections?

These fungi can be found almost everywhere; powdery mildew spores over winter in plant debris and start to produce additional spores for spring. Splashing water, wind, or insects can carry the spores to other plants. It’s vital to disinfect all tools and properly maintain either the garden or the grow room.

High humidity or dampness are conditions that encourage both the growth and the spread of the spores. Poor air circulation in crowded plants doesn’t allow plants to dry properly, which can increase the likelihood of highly infectious spore clumps. Prolonged rain and extreme heat conditions decrease the chance of powdery mildew.


Increase the Calcium Uptake

Increasing your plants’ calcium uptake can help to give plants a natural protection against this disease. Plants make use of calcium to strengthen cell walls, storing unused calcium in a vacuole inside the cell. A part of this nutrient will react with pectic acid and form pectin - which is the glue binding cell walls together.

This allows for extra pectin between plant cells instead of water, resulting in healthier and stronger plants with much thicker cell walls. Any powdery mildew spores that land on leaves will send down their feeding tube to target the water between the cells. This allows for germination and subsequent spread of the fungi.

Having thicker cell walls can make a big difference for plants, as the spores won’t be able to penetrate the cells quickly. The spores dry up and die when the germination feeding tube finally pierces the cells. Although the extra pectin doesn’t kill the powdery mildew, it helps to prevent its spreading.

Magne-Cal + supports plants’ healthy growth through its levels of magnesium and calcium. It strengthens cells and regulates nutrient transport while supporting photosynthesis and enzyme processes.

Magne-Cal +

Curing and Preventing Powdery Mildew

Essence Leaf-Disease Cure helps to cure and prevent diseases like mildew, botrytis, and a wide range of other leaf diseases. Containing more than 20 strains of microorganisms, Essence works quickly and efficiently. It combats existing pathogens, forms a protective barrier against airborne spores, promotes stronger and healthier growth, and improves stress and disease resistance.

For the garden, a Bugicide can be a good solution. Alongside controlling a wide range of mildews and other pests, these don’t gain resistance to Bugicide. Additionally, it’s safe for bees and birds, great for both outdoor and indoor growing, easily used up top harvest time, and effective for all fruits, vegetables, and flowers.

To know more about our wide range of products that promote healthy and sturdy plants, make sure to contact us on 01695 554 080 - our expert team is always happy to address your queries. Alternatively, our FAQs page has plenty of useful information.

Our Blog: Hydroponic Tips & Tricks

Whether you are an expert who already has a thriving crop of healthy plants, or you are trying to grow your very first hydroponic yield, we can help you to grow the strong and healthy crops you have always wanted.

Here at Plant Magic Plus, our team of gardening experts work very hard behind the scenes to provide you with the high quality nutrients, additives and growing media that will help you to get the most out of your growing plants.

But we understand that successful horticulture is about more than just having good quality chemicals, nutrients or fetilisers, that's why we have written this blog to provide you with the insights, tips and techniques you will need to give your garden that extra magic touch.

From helpful advice about watering your plants in soil and a guide to magnesium nutrients, to top tips about growing hydroponic vegetables and a comprehensive overview of microbes, we’ve got everything covered.


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