Chloride injury: a chloride-shy crop meets a chloride fertiliser
Potato, tobacco, some fruit — chloride is not a free ride.
- Chloride-sensitive crops scorch at the margin.
- Ask which chloride fertiliser was used.
- Potato, tobacco, some fruit are touchy.
- Potassium also scorches margins, but scorch right after potassium chloride is more chloride or salt.
- Salt injury often whites the surface; chloride injury depends on the fertiliser kind.
- Don’t use potassium chloride on chloride-sensitive crops; don’t treat every scorch as potassium lack.
- Which potassium to use: Chloride-shy crops: potassium sulphate. Rate follows a soil test. Read the ingredients, not the spoken trade name
- Name what you see before you feed.
- If leaves, roots and the surface disagree, stop.
What you see in the field
Chloride-sensitive crops scorch at the margin. Ask which chloride fertiliser was used. Potato, tobacco, some fruit are touchy.Ask what was applied, and how much. Injury in a line with granules in the seed furrow matches this page. Scattered patches look more like disease. Do not stack another bag.
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 also scorches margins, but scorch right after potassium chloride is more chloride or salt.
Looks like “Salt injury”
Salt injury often whites the surface; chloride injury depends on the fertiliser kind.
Do this / don’t do that
- 1Chloride-sensitive crops scorch at the margin. Ask which chloride fertiliser was used. Potato, tobacco, some fruit are touchy.
- 2Read the bag. Switch chloride-sensitive crops to sulphate-K via extension. Dilute what is already there; stop chloride fertiliser.
- 3Don’t use potassium chloride on chloride-sensitive crops. 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 use potassium chloride on chloride-sensitive crops; don’t treat every scorch as potassium lack.
Rate range
Which potassium to use
Chloride-shy crops: potassium sulphate. Rate follows a soil test
Read the ingredients, not the spoken trade name.
These are ranges. Confirm with your local extension station and the product label.
How soon after a spray or a feed it showed
A 1–3 day burst looks more like spray injury / fertiliser burn.
When you see Chloride-sensitive crops scorch at the margin. Ask which chloride fertiliser was used. Potato, test. Walk an S and mix — one hole is not the field.
Lesson video
2026-03-11 · 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