The symptoms visible on the strawberry leaves in your images, such as the white, powdery fungal growth on the upper leaf surface along with reddish-brown discoloration and necrotic patches on the underside, may be characteristic of powdery mildew, caused by the fungus Podosphaera aphanis, or spider mite infestation.

Powdery mildew and spider mite infestation are two major threats to strawberry cultivation, often favored by warm, humid conditions with poor ventilation. Powdery mildew, caused by Podosphaera aphanis, presents as white, powdery growth on the upper leaf surfaces, accompanied by leaf curling, purpling, and reduced photosynthesis, ultimately leading to stunted growth and poor fruit quality. Similarly, spider mites, particularly Tetranychus urticae, infest the undersides of leaves, sucking sap and causing yellow stippling, bronzing, fine webbing, and eventual leaf drying. Both issues can severely reduce strawberry yield and marketability. Management of powdery mildew involves applying fungicides like myclobutanil or sulfur-based sprays, enhancing air circulation, and using resistant varieties. For spider mites, introducing predatory mites such as Phytoseiulus persimilis, applying miticides, and maintaining optimal humidity are effective strategies. Regular monitoring and an integrated approach combining cultural, chemical, and biological methods are essential for preventing and controlling these damaging pests and diseases in strawberries. You can match the symptoms and take preventive measures accordingly.

Thank you Shweta. But this is not powdery mildew. There are no signs of a organism on both surfaces. The white powdery appearance due a chemical application.