Gadenin日本語Get the appCheck these first
- What colour are the spots, and do they have a yellow halo?
- Are there concentric rings or a mosaic pattern?
- Are the spots only on leaves, or also on stems and fruit?
Most likely causes
From the pests and diseases recorded for this plant, the ones whose symptoms match, most serious first. Symptoms alone rarely confirm a cause, so use the linked page to check the signs and treatment.
Black Spot
On roses, dark brown lesions with radiating edges form on the leaves, which yellow around them and drop. On pear, sooty black lesions appear on leaves, fruit and the calyx of young fruit, deforming the fruit.
General description; not specific to this plant.
How to identify and treat: Black SpotRing Rot
The bark of branches and trunk becomes rough and warty, serving as the inoculum source. Fruit develops round brown lesions that soften and rot in concentric rings.
General description; not specific to this plant.
How to identify and treat: Ring RotPear Rust
Round orange-red lesions form on the upper leaf surface with small black specks in the center. The underside of the lesion swells into hair-like tubes, and heavy infection causes leaf drop and loss of vigor.
General description; not specific to this plant.
How to identify and treat: Pear RustOther possible causes
- Bacterial Canker — Leaf margins scorch and die back, and splitting the stem reveals browned vascular tissue. …
- Powdery Mildew — White patches appear scattered on the upper leaf surface at first, then the whole leaf is …
- Gray Mold — Water-soaked brown lesions form on flowers, fruit and leaves, densely covered by a fuzzy g…
- Late Blight — Dark green water-soaked lesions appear on the leaves and expand quickly into brown dead ti…
- Anthracnose — Light brown to dark brown round lesions with sharp margins form on leaves and fruit, sligh…
- Brown Leaf Spot — Small light brown to gray-brown spots form on the leaves and enlarge into irregular lesion…
- Brown Rot — Blossoms brown and die, and round brown lesions on fruit expand rapidly. Grayish white pow…
- Root-lesion Nematode — Elongated blackish brown necrotic lesions form on the root surface and fine roots rot away…
Other symptoms on this plant
What other growers did about it
A page like this one can tell you what japanese pear leaf spots is and what to try. What it cannot tell you is what actually happened to someone who had it on the same plant, at the same point in the season, and what they did next.
Gadenin is a free garden journal built around that. You photograph the plant, tag what you are seeing, and the entries line up by date for each plant you grow.
- Tag the problem and the app tells you how many other growers have logged the same thing on the same plant.
- Growers who make their records public can be followed, so you can read what they did and how it turned out.
- Next season your own entries come back at the same point in the year, so you check the plant before it starts.
Free on iPhone. Recording, tagging and reading public records cost nothing.