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Calcium shortage: dead tips, blossom-end rot, split fruit

Calcium in the soil is not calcium in the fruit. Water flow carries it.

Nutrient shortage
Speed
  1. Growing point stops, blossom-end rot, split fruit, scorched heart leaves.
  2. Old leaves relatively fine.
  3. Worse with wet-dry swings.
  4. Potassium shortage starts on old-leaf margins; calcium shortage starts at the growing point and young fruit.
  5. Disease spreads, with lesions or mycelium; blossom-end rot sits on the same spot and tracks watering swings.
  6. Don’t treat blossom-end rot as a pathogen; don’t chase calcium lack with urea.
  7. Foliar calcium (young fruit / heart-leaf first aid): Split the labelled rate. After fruit set, a small patch first, not at noon. Acid soil still asks about soil calcium; salty soil drops salt first
  8. Name what you see before you feed.
  9. If leaves, roots and the surface disagree, stop.

What you see in the field

Growing point stops, blossom-end rot, split fruit, scorched heart leaves. Old leaves relatively fine. Worse with wet-dry swings.First the leaf position: new or old, even yellow or between the veins. If that does not match, do not fertilise yet. Pull one plant and read whether the roots are white, brown or foul.

A sketch. Do not fertilise from the picture alone.

Tap to enlarge. The caption says what to photograph. Missing field photos are marked as to-be-added.

Why it looks like this

The field looks like this because the root cannot take water or nutrients the usual way. Fix the soil condition first — drainage, salt, acidity, compaction or a salt of fertiliser — then a thin feed. Rates live in the range on this page; confirm with a local station and the label.

Easy to mix up

  • Looks like “Potassium-scorched margins”

    Potassium shortage starts on old-leaf margins; calcium shortage starts at the growing point and young fruit.

  • Looks like “Fruit rot”

    Disease spreads, with lesions or mycelium; blossom-end rot sits on the same spot and tracks watering swings.

Do this / don’t do that

  1. 1Growing point stops, blossom-end rot, split fruit, scorched heart leaves. Old leaves relatively fine. Worse with wet-dry swings.
  2. 2Steady the water first. Foliar calcium on young fruit and heart leaves at the label floor, small patch. On acid soil ask pH and soil calcium — a spray is not the soil job.
  3. 3Don’t treat blossom-end rot as a pathogen. Use the range on this page only as a range. Confirm with a local station and the product label.

Don’t do this first

  • Don’t treat blossom-end rot as a pathogen; don’t chase calcium lack with urea.

Rate range

Foliar calcium (young fruit / heart-leaf first aid)

Split the labelled rate. After fruit set, a small patch first, not at noon

Acid soil still asks about soil calcium; salty soil drops salt first.

These are ranges. Confirm with your local extension station and the product label.

Exchangeable calcium

Calcium the soil can hold

Acid soil and sand run low easily.

Watering swings

Whether calcium can reach the fruit

Wet-dry swings hurt fruit most.

When you see Growing point stops, test. Take soil from the bad patch and from a greener neighbour, separately.

Lesson video

2026-03-07 · Li Zeyu · For learning. Serious damage: local agronomist or a soil test.

For learning only. Fertiliser and pesticide decisions need a local agronomist and a soil test.

Not sure? Photograph the field to identify the problem