Plant disease & disorder profiles
Showing 5 of 74 profiles: symptoms, spread, host crops, and organic-first treatments.
Bean rust
Uromyces appendiculatus
A fungus that produces powdery, rust-orange pustules on the underside of bean leaves, easily rubbed off on a finger like actual rust dust.
- Hosts
- Bush bean
Brown rot
Monilinia fructicola
A fast-moving fungus that blights blossoms in spring and then rots ripening stone fruit into a soft brown mass covered in gray-tan powdery spore tufts, often spreading fruit to fruit where they touch.
- Hosts
- Peach, Plum, Cherry
Corn smut
Ustilago maydis
A striking fungus that replaces developing corn kernels (and sometimes tassels) with large gray-silver galls filled with sooty black spores; in some cuisines the young galls are harvested as a delicacy (huitlacoche).
- Hosts
- Sweet corn
Peach leaf curl
Taphrina deformans
A fungus that infects peach and nectarine buds before they even open in spring, causing dramatically puckered, reddened, distorted new leaves as soon as they emerge.
- Hosts
- Peach
Powdery mildew
Podosphaera/Erysiphe/Golovinomyces spp. (host-specific species)
Unmistakable white-gray powdery coating on leaf surfaces, caused by several host-specific fungal species. Unlike most fungal diseases it thrives in dry air and doesn't need free water on the leaf to infect.
- Hosts
- Zucchini, Winter squash, Pumpkin, Cucumber
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