Acid soil and calcium shortage together: blossom-end rot is not only a foliar calcium job
If the root is being bitten, spraying the fruit is a delay.
- Blossom-end rot is often sprayed as anthracnose. Ask about watering and pH first.
- Salt injury often has white crust; calcium shortage does not need a white surface.
- Don’t live on foliar calcium; don’t chase the rot with urea.
- Foliar calcium: Labelled lower rate, split. First aid. It does not replace changing the soil
- Name what you see before you feed.
- If leaves, roots and the surface disagree, stop.
- Acid soil leaches calcium.
- Calcium is a brick; drought makes the root miss it.
What you see in the field
Blossom-end rot, split fruit, scorched heart leaves — a calcium spray is only a rescue.Walk the worst strip. Pull one plant, rinse the roots at the ditch without rubbing the tips, and read white tips versus brown bald ones. A rusty film on water is extra, not required. Grain land and tea do not share a pH target.
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 “Spraying as if it were disease”
Blossom-end rot is often sprayed as anthracnose. Ask about watering and pH first.
Looks like “Salt-scorched margins”
Salt injury often has white crust; calcium shortage does not need a white surface.
Do this / don’t do that
- 1Compare the worst plants with a neighbour ridge. Photograph whole plant, close-up and soil surface before you add fertiliser.
- 2Match roots, leaves and the soil surface to this guide. If they do not line up, do not copy a bag count.
- 3Use the rate range on this page only as a range. Confirm with a local station and the product label.
Don’t do this first
- Don’t live on foliar calcium; don’t chase the rot with urea.
Rate range
Foliar calcium
Labelled lower rate, split
First aid. It does not replace changing the soil.
Lime material
Follow pH and a soil test
Lifting acid also adds calcium. Better too little than too much.
These are ranges. Confirm with your local extension station and the product label.
When you see Blossom-end rot, test. Mix several spots of the tilled layer; skip the edge and the manure heap.
Lesson video
2026-03-18 · 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