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Gallery Mucor Rot

ID Gallery: Mucor Rot

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Mucor Rot of Apple and Pear

Mucor rot can cause significant losses of fruit, but is generally not a major problem, when good harvest management and water sanitation practices at packing are implemented.

For more information about mucor rot and it’s management visit our page Mucor Rot Postharvest Disease.

Click on images below to to full size.

Photo credits to Achour Amiri and Keith van den Broek, WSU TFREC, unless otherwise noted.

yellow-green apple with large light brown area

Mucor rot (Mucor piriformis) on a Golden Delicious apple showing very soft, juicy, decayed tissue with a sharp margin. Mucor rot decay often has a sweet odor. Photo: CL Xiao, USDA-ARS.

red apple with a large brown spot with creased skin

Mucor rot on the side of a Pink Lady apple. Photo: TJ Mullinex, Good Fruit Grower.

green apple with a large damage spot with brown and a web of gray

Early mucor symptoms starting from a wound on Granny Smith. Note the white mycelium emerging.

entirely damaged apple, brown with white spots and a substantial dark spot

Advanced Mucor rot on a Fuji apple. Entire fruit is extremely soft and juicy. Notice dark sporangia on fruit surface.

half of an apple with damaged portion removed

Cross section of Mucor rot on a Fuji apple. Note juicy tissue easily separated from healthy tissue.

half of a very damaged apple, shriveled and brown with some long white fuzz

Cross section of Mucor rot on a Granny Smith apple. Note juicy-watery tissue and white sporangiophores emerging from the calyx-end.

almost entirely brown apple with a lot of long light gray fuzz

Actively growing Mucor infection on Granny Smith apple under high humidity causing the emergence of fuzzy-white sporangiophores.

brown, shriveled apple with long light gray fuzz

Advanced late-stage Mucor infection on Granny Smith.

pear with damage around the stem

Early stage infection of Mucor rot starting from a wounded area around the stem-end on d’ Anjou pear. Photo: CL Xioa, USDA-ARS.

a pear, half brown and shriveled

Advanced stage of Mucor rot originating from stem infection on a d’Anjou pear fruit; gray mycelium with dark sporangia. Photo: CL Xiao, USDA-ARS.

a very brown pear with a patch of gray fuzz

Stem-end Mucor infection carrying sporangiophores and black sporangia on Bartlett pear.

a brown pear almost entirely damaged

Advanced stage of Mucor rot on a d’Anjou pear fruit; gray mycelium with dark sporangia. Photo: CL Xiao, USDA-ARS.

close-up of dark gray fuzz on a brown fruit

Abundant fuzzy sporangiophores (mycelium) carrying black sporangia.

Washington State University