Tip Burn

Tip Burn is a physiological symptom syndrome in which rapidly expanding leaf tips or margins become necrotic. It is common in lettuce, cabbage, strawberry, ornamentals, and protected crops. The immediate mechanism is often localized calcium delivery failure in young tissue, but high salinity, fertilizer concentration, drought, root injury, low transpiration in humid enclosures, pesticide exposure, and species-specific leaf physiology can produce similar edge death. Tip Burn is therefore narrower than general Calcium Deficiency but still requires root-zone and environmental confirmation.

Identification

Confirm whether the youngest expanding leaves or enclosed inner leaves are affected, and whether necrosis begins at tips or margins. Record humidity, airflow, growth rate, irrigation, EC, calcium, ammonium, root condition, and recent sprays. Internal lettuce tipburn can hide within apparently sound heads. Salt injury often affects older exposed margins; bacterial or fungal blights may expand irregularly or show signs. Tissue analysis alone may not reflect localized calcium transport failure.

Symptoms / Signs

Leaf tips and margins become pale, translucent, tan, or brown and turn papery. Inner lettuce leaves, cabbage heads, strawberry leaflets, or fast-growing ornamental shoots may be affected while older leaves remain green. Severe tissue can support secondary soft rot. Existing necrotic margins do not recover.

Life Cycle / Process

Tip burn develops during rapid leaf expansion when local tissue demand, transpiration, root uptake, and calcium movement become mismatched. High humidity can suppress water flow to enclosed leaves, while salinity or damaged roots reduce uptake. The disorder is not contagious. New leaves can remain healthy after conditions are corrected.

Prevention

Maintain even moisture, appropriate EC and pH, balanced calcium and ammonium, functional roots, spacing, and airflow. Avoid sudden fertilizer or growth surges. In protected lettuce, crop-specific airflow or nighttime humidity management can reduce internal tipburn. Foliar calcium has limited ability to reach enclosed tissue and should not replace root-zone correction.

Management / Control

Remove decayed tissue or unsalable heads, but retain samples first. Correct irrigation, humidity, airflow, and root health before adding calcium. Test water, solution, and tissue. Reduce excessive EC or ammonium and rebalance the complete nutrient program. Judge response by new leaves.

Procedure Steps

1. Open heads or crowns and photograph inner and outer leaves. 2. Record humidity, airflow, irrigation, and growth rate. 3. Measure pH and EC. 4. inspect roots and recent sprays. 5. obtain nutrient or solution analysis. 6. correct water, airflow, and root stress. 7. apply only calculated nutrient changes. 8. monitor new tissue.

Safety Notes

Calcium and fertilizer concentrates can irritate skin and eyes and increase salinity when overapplied. Use ventilation and protective equipment. Secondary decayed tissue should not be marketed as sound produce. Do not apply foliar products to edible crops unless labeled.