Hopperburn is the injury caused by potato leafhopper (Empoasca fabae) feeding. The insect's saliva disrupts the leaf's vascular tissue, so the leaf yellows, then browns, starting at the tip and margins in a V-shaped pattern, and may curl. UConn Extension and Utah State hemp notes describe it.
In practice
Hopperburn is easily mistaken for nutrient tip burn or heat stress. Check leaf undersides for small, wedge-shaped green leafhoppers that run sideways, and use yellow sticky cards outdoors. On cannabis it is usually a minor, outdoor problem; beet leafhopper and curly top virus matter far more.
Don't confuse with
- Nutrient burn: tip burn from high EC, no insects present.
- Curly top: a virus spread by the beet leafhopper, with curling and stunting.
Small wedge-shaped jumping insects of the family Cicadellidae that suck plant sap; the beet leafhopper (Circulifer tenellus) spreads beet curly top virus to hemp.Hemp is cannabis grown for fibre, seed or other uses and, in many laws, defined as Cannabis sativa with no more than 0.3% THC by dry weight.Nutrient burn is browning and crisping of leaf tips, then margins, caused by a root-zone salt concentration (EC) higher than the plant can handle.Heat stress is damage or slowed growth when leaf or canopy temperature rises above what the plant can handle, typically above about 30–32 °C (86–90 °F) in cannabis.A coloured card coated in non-drying glue that catches flying insects, used mainly to monitor pest trends: yellow for gnats, whiteflies and aphids, blue for thrips.BCTV, a leafhopper-spread curtovirus that stunts outdoor hemp and cannabis, curling and yellowing new leaves; there is no cure once a plant is infected.EC (electrical conductivity) measures how well a solution conducts electricity, a proxy for total dissolved salts; growers read it in mS/cm to gauge nutrient strength.An infectious particle of nucleic acid in a protein coat that replicates inside plant cells; on cannabis, often insect-spread and incurable once infected.Systematic, regular inspection of plants, traps and roots to detect pests and disease early, identify them correctly and record numbers for decisions.
