Brittle stems that snap easily
Plant-wide; often with stunting and small, low-resin flowers..
- Also called
- stems break easily
- brittle branches
- snapping stems
- stem brittle
Likely causes, most likely first
Ranked for this sign on its own. Your stage, medium and readings change the order, so run the checker for your plant.
PossibleHop latent viroid (dudding)
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.
How to confirm it
- 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.
- 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.
Less likelyHemp russet mites
Fix: Confirm at 30-60x (they look like moving dust). Remove badly infested plants; release predatory mites preventively; quarantine clones; leave a plant-free gap between cycles.
Recovery: Bronzing stops climbing and no live mites at 30-60x in 2 weeks.
How to confirm it
- 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.
Look for
Stems that snap cleanly when bent gently, on a stunted plant..
The full guide: Hop latent viroid (HLVd, 'dudding') and other cannabis viruses
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.
