# Mottled mosaic or yellow streaks, distorted leaves: likely causes and fixes

> Mottled mosaic or yellow streaks, distorted leaves on cannabis is most often Plant virus (e.g. beet curly top, lettuce chlorosis virus), Hop latent viroid (dudding) or Herbicide drift or residue. How to tell them apart, the fix for each and what recovery looks like.

Also called: mosaic pattern on leaves, yellow streaks, mottled leaves, blotchy yellow pattern, virus looking leaves.

Run the checker with this sign: https://genetixbay.com/knowledge/diagnose/?at=whole&s=mosaic-mottle

## Likely causes, most likely first

### Plant virus (e.g. beet curly top, lettuce chlorosis virus) (Possible)

- Kind: Disease; urgency: Deal with it this week
- Fix: No cure: remove the plant. Control insect vectors (leafhoppers outdoors for curly top; whiteflies for some others) and test clone sources.
- Recovery: No new symptomatic plants over the next 2-4 weeks.
- Confirm: Send a sample to a plant diagnostic lab: For rots, wilts, leaf spots and viruses you can't separate by eye, send a fresh sample (whole plant with roots or a wilting branch with healthy and diseased tissue) in a sealed bag to a university or commercial plant diagnostic clinic. Results in days to 2 weeks.
- Confirm: Magnifier check of leaf undersides and new growth: Use a 10-20x loupe for spider mites, thrips, aphids and whiteflies, and a 30-60x lens or clip-on phone macro for broad and russet mites. Check the undersides of 10 affected leaves across several plants and the newest shoot tips, in white light. Look for moving dots, eggs, shed skins, webbing, slender insects with black specks, and glassy specks on new growth.
- Article: [Hop latent viroid (HLVd, 'dudding') and other cannabis viruses](https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.md)

### Hop latent viroid (dudding) (Less likely)

- Kind: Disease; urgency: Act within a day or two
- Fix: No cure in a plant. Test mothers (roots and leaves) by RT-PCR or RT-qPCR, discard positives, disinfect tools with 10% bleach or heat (alcohol and peroxide don't inactivate it), and use meristem tissue culture to rescue valuable genetics. Don't take cuttings from stunted plants.
- Recovery: Negative tests on new mothers; no more duds in the next cycle.
- Confirm: Lab test for hop latent viroid (RT-PCR or RT-qPCR): Send root and leaf samples (roots detect HLVd earlier in young plants) to a lab offering HLVd RT-PCR or RT-qPCR. Test mother plants and any stunted plant among healthy siblings. A positive plant cannot be cured; tissue culture of meristem tips can rescue genetics.
- Confirm: Compare with siblings or the same cut: Put the affected plant beside siblings or clones of the same cut in the same conditions. A trait shared by all of a cultivar (purple stems, foxtailing, pale colour) is genetic; a problem on one plant points to its roots, a virus or its genetics; a problem on every cultivar points to the environment or feed.
- Article: [Hop latent viroid (HLVd, 'dudding') and other cannabis viruses](https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.md)

### Herbicide drift or residue (Less likely)

- Kind: Physical damage; urgency: Deal with it this week
- Fix: Outdoors or with contaminated compost, manure or straw (persistent herbicide residues). Remove the source, repot into clean media; new growth may normalise slowly. Cannabis-specific symptom descriptions are scarce.
- Recovery: New growth normalises over 2-4 weeks after the source is removed.
- Confirm: Magnifier check of leaf undersides and new growth: Use a 10-20x loupe for spider mites, thrips, aphids and whiteflies, and a 30-60x lens or clip-on phone macro for broad and russet mites. Check the undersides of 10 affected leaves across several plants and the newest shoot tips, in white light. Look for moving dots, eggs, shed skins, webbing, slender insects with black specks, and glassy specks on new growth.
- Confirm: Send a sample to a plant diagnostic lab: For rots, wilts, leaf spots and viruses you can't separate by eye, send a fresh sample (whole plant with roots or a wilting branch with healthy and diseased tissue) in a sealed bag to a university or commercial plant diagnostic clinic. Results in days to 2 weeks.
- Article: [Why are my cannabis leaves curling? The master curling and clawing decision tree](https://genetixbay.com/knowledge/diagnosis/curling-clawing-decision-tree.md)

## Note

Guidance, not a guarantee. The checker weighs common causes against what you tell it; confirm with the tests before you treat, change one thing at a time and watch the new growth.