How to recognize and combat powdery mildew on fruit

Powdery mildew causes a disease easily recognizable by the formation of a whitish, powdery, mealy coating on the surface of the fruit. The infection can begin with small, isolated colonies that subsequently increase in size and can eventually cover a significant portion of the surface. As the disease progresses, the affected tissues may exhibit developmental alterations, loss of commercial quality, and surface damage that contributes to fruit deterioration. In severe infestations, the infection can cause deformities, reduced growth, and uneven ripening, as well as considerably decreasing the commercial value of the harvest. In certain fruits, colonization during the early stages of development can cause permanent damage to the epidermis, while later infections may manifest primarily as whitish coatings and surface lesions.

• Appearance of whitish, powdery spots or colonies on the surface of the fruit.

• Formation of white or grayish mycelium that can progressively spread across the epidermis.

• Abundant presence of white powder due to spore production on affected tissues.

• Development of discolored, yellowish, or brownish areas around colonized zones.

• Fruit deformation or irregular growth when infection occurs during early stages of development.

• Formation of surface lesions, russeting, cracks, or epidermal alterations in certain crops and under certain conditions.

• Reduction in the visual and commercial quality of the fruit.

• Uneven ripening and reduced normal development when the infection is severe.

• Necrosis and tissue deterioration in severe infestations or when lesions persist for extended periods.

• Appearance of new colonies on nearby fruit due to the airborne dispersal of conidia.