Ampelomyces quisqualis strain AQ10

Ampelomyces quisqualis is a specialized hyperparasitic fungus that acts as a natural antagonist to powdery mildew pathogens. Its primary mechanism involves invading the hyphae, conidiophores, and cleistothecia of the host fungus.

Once the spores of the hyperparasite land on the powdery mildew infection site, they germinate and penetrate the pathogen's structures. The internal parasitism results in the depletion of the pathogen's resources and ultimately kills the powdery mildew colony.

The fungus functions as a living regulatory agent, effectively colonizing the affected surface and preventing the pathogen from completing its life cycle. It is particularly effective at reducing the spore production of the powdery mildew fungus.

This biological tool is well-suited for integrated pest management (IPM) programs where reducing chemical residues is a priority. It provides a non-toxic method for managing crop diseases in greenhouses and fields.

The efficacy of the strain AQ10 relies heavily on environmental conditions, particularly humidity, which is necessary for the hyperparasite to colonize the target fungus successfully.

The primary targets are various species of the order Erysiphales, commonly known as powdery mildew. This includes a wide range of horticultural, viticultural, and ornamental crops prone to these fungal infections.

Common applications include:

• Grapes;
• Cucurbits such as cucumbers and squash;
• Strawberries and small fruits;
• Roses and other greenhouse ornamentals.

Application rates typically range from 100g to 500g per hectare depending on crop density and disease severity. Early detection and preventative application are highly recommended to establish the hyperparasite population.

Regular applications may be required in humid conditions to maintain control. An interval of 7 to 14 days is standard, though this can be adjusted based on the initial level of disease infestation.

The main limitation is incompatibility with most synthetic chemical fungicides, which may be detrimental to the Ampelomyces spores. A significant waiting period is often required when switching between chemical and biological treatments.

Environmental requirements are strict; the hyperparasite needs moisture for infection to occur. Extremely dry or cold weather significantly reduces its effectiveness, as the fungus cannot thrive or multiply under such stress conditions.