Verdia · Library
Powdery mildew observations
Record where a powdery coating appears on leaves, shoots, flowers or fruit, and see how Verdia routes Erysiphe, Podosphaera and 9 more genera to it.
How the app recognises powdery mildew
Verdia's powdery mildew group lists 11 genera: Erysiphe, Podosphaera, Golovinomyces, Oidium, Leveillula, Sphaerotheca, Blumeria, Microsphaera, Uncinula, Oidiopsis and Phyllactinia. If the first word of the returned name is not one of them, the app looks for erysiphales or erysiphaceae in the name. These keywords are the first in the app's keyword list, so they are checked before any other group.
Powdery mildew is a group of diseases. A white mark can also have other causes, which is why the score threshold and the photo both matter.
On the result screen the name shown is Pl@ntNet's common name when one exists, otherwise the scientific name, followed by the score as a whole percentage. Routing always uses the scientific name, so a common name in your language does not change which steps appear.
What to record
- Record where the coating appears: leaves, shoots, flowers or fruit.
- Photograph its pattern, close up and from arm's length.
- Note whether new growth is affected or only older leaves.
- Write down the plant's name and growing conditions, such as spacing and how it is watered.
Reading a Podosphaera result
With Podosphaera xanthii as the top result at 61 percent, the genus podosphaera matches and the app shows its powdery mildew steps. Two are on this page: removing the worst leaves into the bin rather than the compost, and giving the plant more air by spacing pots and watering the soil instead of the leaves. The third step names a product and is held back.
- Name returned
- Podosphaera xanthii
- Top score
- 61%
- Rule that matched
- genus podosphaera
- Powdery mildew steps shown here
- 2 of 3
At 8 percent the app would instead say it could not spot a clear problem.
Mistakes
- Treating every white mark as powdery mildew.
- Removing large amounts of foliage instead of the worst leaves.
- Keeping pots crowded after reading the airflow step.
- Forgetting to note whether new growth is involved.
Limits
A genus match points to general steps, not a confirmed cause. The RHS powdery mildews page listed below describes the diseases; the ASPCA list covers pet safety.