Biocontrol – Powdery mildew

Powdery mildew: understanding and treating this fungal disease

Powdery mildew, a widespread fungal infection known for its conspicuous white powdery growth on plant surfaces, presents a major challenge to crop health on a global scale. As farmers grapple with its detrimental effects, understanding and implementing effective management strategies becomes paramount. Explore comprehensive approaches to combatting this agricultural threat and safeguarding crop productivity amidst ongoing environmental pressures.

Share on:

Powdery mildew: understanding and treating this fungal disease 

Powdery mildew is a fungal disease that threatens a broad spectrum of crops, resulting in the appearance of a distinctive white powdery coating on plant leaves, stems and flowers. Although, it appears on the surface of crops, this fungal affliction can have profound consequences on plant health, appearance and performance, especially in grapes, apples, cucurbits, tomatoes and strawberries. The regions that are most adversely affected by powdery mildew include major agricultural areas in North America, Europe and Asia.1 

What is powdery mildew? 

Powdery mildew is caused by many different species of ascomycete fungi in the Erysiphales order. This fungal disease targets various parts of plants including their foliage, stems, flowers and fruits. The most characteristic symptom is the formation of superficial fungal growth that creates a dusty white covering on the plant’s surface. 

The environmental conditions that are conducive to the formation of powdery mildew are similar to those of other fungi: 

  • Relative humidity between 40% and 80%; the damper the conditions, the faster the fungus proliferates.
  • Mild temperatures between 17ºC and 28ºC; temperatures above 40ºC halt its development.
  • Low light conditions with an incubation period of 8 to 10 days

Identifying symptoms 

Spotting the signs of incipient powdery mildew and having an efficient treatment to hand are crucial to quickly halt its spread. The main symptoms are: 

  • Patches of white powdery fungus which spread across upper and lower leaves, flowers and fruits.
  • Possible stunting and distortion of affected tissue
  • In certain cases, early infection does not bring noticeable symptoms. However, some species of powdery mildew can induce striking colour changes, giving infected areas a distinctive purple-brown hue.

Wide-ranging impact 

One of the main problems of this disease is its wide-ranging impact, affecting fruit trees such as apple trees, as well as ornamentals and major horticultural crops, such as melons and tomatoes. As concerns about the impact of climate change on agriculture grow, there is a need to explore the potential correlation between changing climate patterns and the increasing prevalence of powdery mildew.2 

Dealing with powdery mildew: Ospo-Vi55® a next-generation powdery mildew biological eradicant 

Biofungicides are effective natural allies against fungal diseases like powdery mildew. Unlike traditional chemical products, they help to reduce residue, while combatting resistance and enhancing stress tolerance. 

At Rovensa Next, we understand our growers’ real day-to-day sustainability challenges. We work hard to develop innovative biosolutions so they can protect their crops without compromising on performance whilst complying with the latest regulations. 

Ospo-Vi55® is a next-generation biofungicide that eradicates powdery mildew and prevents Venturia. Its effectiveness comes from the combination of the Bacillus subtilis strain IAB/BS03 and specific solid synergetic co-formulants especially selected to boost its fungicidal effect.* As many study results have shown,3 just one application of Ospo-Vi55® 5 g/L can eradicate 96.4% of powdery mildew mycelium. 

Ospo-Vi55®’s exclusive Bioevology® formulation technology maximises the fungicidal activity of Bacillus subtilis. When this technology is applied to the formulation of microorganisms , it intensifies the fungicidal effect of the final product, delivering complex products with improved action. 

Powdery mildew: understanding and treating this fungal disease


Advantages of applying Ospo-Vi55® 

  • Healthy crop protection against powdery mildew 
  • Crop production not halted or reduced. 
  • Fast-acting, with positive effects in just 24-48 hours 
  • No pesticide residues and no safety periods 
  • Friendly to beneficial insects 
  • Excellent resistance management 
  • Suitable for organic and integrated pest management 


Contact the Rovensa Next team through our Contact form for further information on how to deal with powdery mildew. 


* Rovensa Next is a global business unit that delivers solutions for agriculture around the globe. The information shared here may vary depending on your location. Please contact us using our Contact form to confirm whether the product is available in your country, or should you have any queries or require any additional information. Thank you.


[1] Różewicz M, Wyzińska M, Grabiński J. The Most Important Fungal Diseases of Cereals—Problems and Possible Solutions. Agronomy. 2021; 11(4):714. Science Direct.

[2] Modelling the impact of climate change on the interaction between grapevine and its pests and pathogens: European grapevine moth and powdery mildew

[3] Powdery mildew (Erysiphe necator) field trial on vine (Vitis vinifera), (Chile). Rovensa Next 

How we help you:

Through biosolutions developed to meet crop needs from seed to shelf.

By product categories

Agricultural Bionutrition

Agricultural Biocontrol

Agricultural Adjuvants and Correctors

Let’s grow together.

We help you accelerate the green transition. We offer broad local knowledge and global technical assistance.

"*" indicates required fields