Symptom differential
Marginal Necrosis / Leaf-Edge Burn
Browning or death along leaf margins can arise from salinity, water stress, nutrient imbalance, heat or desiccation, root problems, or disease. Margin injury should be mapped by leaf age and canopy location.
Pattern questions
- Does injury begin at tips and move along margins?
- Are upper leaves more affected than lower leaves?
- Is the root zone unusually dry, wet, saline, hot, or cold?
- Did the injury appear suddenly after a feed, spray, or weather event?
Plausible cause categories
- Salinity or excessive root-zone EC
- Water deficit or root dysfunction
- Nutrient imbalance
- Heat or low-humidity stress
- Chemical or spray injury
- Disease or vascular disruption
Discriminating checks
- Measure EC and substrate moisture
- Inspect roots
- Map injury against light and airflow zones
- Review recent sprays and irrigation events
Red flags
- Sudden widespread injury after one event
- Wilting with wet media
- Stem lesions or one-sided branch decline
Visual study guide
- Margin-versus-tip injury plate
- Canopy-location map
- Salinity context diagram
- Spray-event differential