Mosaic viruses on zucchini
Cucurbit virus diseases (ZYMV, CMV, WMV) spread by aphids and mechanically. Fruit becomes lumpy and blotchy and plants are dwarfed. There is no cure — infected plants have to go.
Symptom photos
Symptoms
- Misshapen, lumpy fruit with a light- and dark-green mosaic
- Mottled clearing and flecking on the leaves
- Ragged, distorted leaf margins
- Blistered swellings and puckering of the leaves
- Dwarfed plants with shortened internodes
What it does to the crop
- Fruit completely unmarketable
- A heavy drop in yield and cropping ending early
- No way to cure the plant
- Aphids carrying the virus on to further plants
What encourages it
- A large aphid population around the crop
- Weeds and infected seed acting as a virus source
- Mechanical spread on hands and tools
- Warm weather encouraging aphid flights
Prevention
- Control the aphids that carry the viruses
- Remove and destroy infected plants immediately
- Use resistant varieties and seed from a reliable source
- Wash hands and disinfect tools between plants
- Clear weeds from around the bed
⚠️ Before you reach for a spray
This atlas is informational and still growing — different diseases can look almost identical. Confirm the diagnosis and read the product label before applying any plant protection product. If you are unsure, ask your local extension or advisory service.
Keep the disease atlas with you in the garden
In the app you can identify a disease from photos, work out the spray dose for your own bed and log the treatment in your task calendar. Free, no sign-up, works offline.
Open the atlas in the app →