Nutrient deficiencies
Manganese deficiency in wheat and barley: symptoms and fixes
By the Fert Directory editorial team · Published 24 October 2026 · Last updated 24 October 2026 · Not yet reviewed by a qualified agronomist
Direct answer
Look for patches of pale, floppy plants in an otherwise healthy crop. Middle leaves go first, with yellowing between the veins (interveinal chlorosis), white flecks, then kinking and collapse. It is worst on alkaline soils, some WA gravels and recently limed paddocks, and in dry soil. Confirm with a tissue test; a foliar spray is the main fix.
Key numbers
| What | Figure | Source |
|---|---|---|
| Youngest emerged blade (YEB) tissue test | below 15 ppm (mg/kg) indicates deficiency | Department of Primary Industries and Regional Development, Western Australia (MyCrop) 2017 |
| Whole-top plant test, rough guide | about 17 mg/kg indicates deficiency | Department of Primary Industries and Regional Development, Western Australia (MyCrop) 2017 |
| Reliable soil test for manganese in cereals | none | Department of Primary Industries and Regional Development, Western Australia (MyCrop) 2017 |
| Best Mn at sowing, barley on SA calcareous sandWarooka SA trials, 1960s | 6 kg Mn/ha (25 kg/ha manganese sulphate), plus three foliar sprays | Online Farm Trials (GRDC-funded, More Profit from Crop Nutrition) 1969 |
What manganese deficiency looks like
DPIRD (WA) describes the same signs in wheat and barley:
- Patches of pale, floppy plants in an otherwise green, healthy crop. Plants are often stunted.
- Middle leaves are hit first, but symptoms spread fast to other leaves and the growing point.
- Yellowing or bleaching between the veins (interveinal chlorosis) and/or white dead flecks and blotches. In barley the blotches may have a thin brown rim.
- Leaves often kink, collapse and die. Tillering drops, with lots of leaf and tiller death. With a long deficiency the plant may die.
- Surviving plants produce fewer and smaller heads.
Durum wheat is the most sensitive cereal, barley is in the middle, and bread wheat is the least sensitive, according to University of Adelaide trials in SA and Victoria.
What else could it be?
| Condition | How to tell it apart |
|---|---|
| Zinc deficiency | Zinc gives linear 'tramline' dead streaks and stunted, bunchy plants. Manganese-short plants are more yellow, wilted and floppy, and worse in dry conditions. |
| Nitrogen deficiency or waterlogging | No wilting, interveinal yellowing, leaf kinking or plant death. |
| Iron or sulphur deficiency | New leaves are affected first, and plants do not die. |
Which soils and seasons are at risk
- Coastal alkaline soils.
- In WA, high phosphorus retention index (PRI), water repellent gravels, from south of Moora to Katanning and east from Corrigin to Dumbleyung. It occurs less often on the Esperance sandplain and the mallee north of Esperance.
- Deep gravel areas and recently limed paddocks are usually worst affected.
- Dry soil, high soil pH, alkaline fertilisers and root-pruning herbicides (particularly groups A and B) make it worse.
- In SA, the classic problem soils are very limy (calcareous, over 80% calcium carbonate) soils of southern Yorke Peninsula.
DPIRD notes the patches have shrunk as WA soils have become more acidic. So lime that fixes a sour (acidic) paddock can bring manganese deficiency back. Set lime rates from a soil test: see how to read a soil test and how much lime per hectare.
Testing before you treat
- There is no reliable soil test for manganese in cereals; soil test Mn is poorly related to yield response.
- Use a youngest emerged blade (YEB) tissue test. Below 15 ppm indicates deficiency. A whole-top test of about 17 mg/kg is a rough guide only.
- Compare paired samples from good and poor patches where you can.
- It pays to check: in SARDI trials on Eyre Peninsula in 2015 and 2016, manganese gave no yield response in any form or timing.
Fixing it: foliar, soil, nitrogen or seed?
- Foliar spray is DPIRD's main option.
- Acidifying ammonium nitrogen fertilisers can reduce deficiency by lowering pH and making manganese more available. See urea vs ammonium sulphate.
- Manganese fertiliser applied to the soil is effective but expensive, because high rates and several applications are needed to build up residual value.
- Seed manganese coatings have little effect in correcting the deficiency.
Older SA trials on calcareous sands show why soil manganese alone often falls short. Manganese sulphate at sowing helped growth and delayed symptoms, but crops still showed symptoms by stem elongation (stem extension). The best result came from 6 kg Mn/ha (25 kg/ha manganese sulphate) at sowing plus three foliar sprays. Follow product labels for spray rates.
Products to compare
- Manganese-enriched starters: MAP Manganese and MAP Trace Manganese. Compare MAP Trace with MAP Trace Manganese.
- Compound with manganese: Vigour & Mn.
- Foliar manganese: YaraVita MANTRAC PRO.
- Search all manganese products. For choosing a starter, see MAP vs DAP.
Always check with your agronomist before acting.
What we could not verify
- DPIRD's MyCrop pages for wheat and barley are no longer live; we used Internet Archive copies (last updated July 2017).
- DPIRD does not give foliar spray rates or timings, and we found no current, fetchable Australian guide to them; follow the product label.
- Soil rate data come from 1960s trials on very limy SA sands and may not apply to WA gravels or other soils.
- We found no figure for how much yield a manganese spray recovers in current Australian wheat or barley crops.
References
- Diagnosing manganese deficiency in wheat (DPIRD (WA); Department of Primary Industries and Regional Development, Western Australia (MyCrop), 2017; Government diagnostic guide (WA). Checked 2026-10-24.)
- Diagnosing manganese deficiency in barley (DPIRD (WA); Department of Primary Industries and Regional Development, Western Australia (MyCrop), 2017; Government diagnostic guide (WA). Checked 2026-10-24.)
- Manganese applications did not improve cereal yields in 2015 and 2016 (South Australian Research and Development Institute (SARDI); Online Farm Trials (GRDC-funded, More Profit from Crop Nutrition), 2016; Field trial summary (SA). Checked 2026-10-24.)
- The correction of manganese deficiency in barley crops (The University of Adelaide; Online Farm Trials (GRDC-funded, More Profit from Crop Nutrition), 1969; Field trial summary (SA, 1963–1969). Checked 2026-10-24.)
- Correction of manganese deficiency in barley crops on calcareous soils. 1. Manganous sulphate applied at sowing and as foliar sprays (Australian Journal of Experimental Agriculture and Animal Husbandry (CSIRO Publishing); CSIRO Publishing, 1973; Peer-reviewed field research (SA). Checked 2026-10-24.)
- Varietal differences in responses to manganese and zinc (The University of Adelaide; Online Farm Trials (GRDC-funded), 2000; Field trial summary (SA and Vic). Checked 2026-10-24.)
More on how we check sources: methodology. Spot an error? Tell us.
General information only. Always check with your agronomist before acting. Full disclaimer