Sorghum Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Sorghum nutrient deficiency is one of the first things to check when the leaves of your batad (sorghum) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, phosphorus, potassium, zinc, iron, sulfur and magnesium. This guide shows where each one starts, how to be sure, and the fertilizer that fixes it.
Start with one question: did the change begin on the old leaves or on the young ones? Nitrogen, phosphorus, potassium and magnesium move inside the plant, so a shortage shows on the old, lower leaves first. But zinc, iron and sulfur stay where the plant first put them, so the young leaves and the growing tip show it first. After that, the color and the pattern narrow down which sorghum nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Sorghum nutrient deficiency signs, old leaves and young leaves
Shows first on the old leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Nitrogen | old, lower leaves, the whole plant | Pale, thin plants whose lower leaves yellow from the tip down the midrib. | Urea 46 0 0, Ammonium sulfate 21 0 0 |
| Phosphorus | old, lower leaves, the roots | Short, stiff, dark green plants with red or purple leaves and sheaths. | Diammonium phosphate 18 46 0, 16 20 0 |
| Potassium | old, lower leaves, leaf edges and tips | Older leaves dry at the tips and edges, with red specks and brown streaks. | Muriate of potash 0 0 60, Complete 14 14 14 |
| Magnesium | old, lower leaves, between the veins | Older leaves turn dark yellow between the veins, then deep red and rusty brown. | Epsom salt / magnesium sulfate, Dolomite |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Zinc | young leaves and the tip, between the veins | White to pale yellow bands on the lower half of young leaves, with a red line on the edges. | Zinc sulfate |
| Iron | young leaves and the tip, between the veins | On limey, high pH soil, young leaves turn yellow to white between green veins, in patches of the field. | Ferrous sulfate, Chelated iron (Fe EDDHA) |
| Sulfur | young leaves and the tip, the whole plant | The young upper leaves turn evenly pale yellow, with no dead spots. | Ammonium sulfate 21 0 0, Gypsum |
Before you buy fertilizer for a sorghum nutrient deficiency
So use the table to pick the likeliest sorghum nutrient deficiency, then read its section below. Also keep in mind that dry soil, standing water, cold nights, a pest or a disease can look the same. That is why it pays to check the roots and the whole field first.
Nitrogen deficiency in sorghum
Plants are stunted, thin and pale yellow green. The older leaves turn yellow from the tip, along the midrib and edges toward the base, then dry. Heads come out small with fewer seeds. You see it most at this stage: from the 5 leaf stage to boot, when the crop grows fastest.
Why nitrogen deficiency happens in batad
Little or no fertilizer, sandy soils, low organic matter, nitrogen washed away by heavy rain. Ratoon crops that were not fed again after the first harvest.
How to tell it apart
Sulfur deficiency gives an even pale yellow on the young leaves without dead tissue. Iron deficiency stripes the young leaves between the veins. To be sure, check that yellowing started on the lowest leaves at the tip and runs down the midrib. Compare with a few rows given urea, and test the soil before the next crop. A leaf test confirms it.
What to apply for nitrogen deficiency
Sidedress Urea 46 0 0 or Ammonium sulfate 21 0 0 beside the rows, following the soil test. Work it in or water it. For quick help, give a 1 percent urea spray (10 g per liter, 160 g in a 16 liter sprayer) or a 2 percent DAP 18 46 0 spray (20 g per liter, 320 g in a 16 liter sprayer). A usual side dress is 2 to 3 bags of Urea 46 0 0 per hectare at 25 to 30 days after planting, hilled in, and the rest before tasseling.
- Urea 46 0 0
- Ammonium sulfate 21 0 0
- Complete 14 14 14
Sold here with nitrogen: Atlas Granular Urea (46 0 0) by Atlas Fertilizer, Amigo Planters Ammonium Chloride by La Filipina (25 0 0), Agripower 46 0 0 (Locally Blended) Coated by Green Acres Agri Tech and Calcipro by Ramgo (15.5 0 0 with 18.8 percent calcium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to urea fertilizer, and the page on nitrogen deficiency in every crop. In anee.io, Anee, the smart farm technician, reads a photo of the leaf and tells you which nutrient is short.
To keep it away, split nitrogen between planting and about 30 days after, and feed a ratoon crop again after cutting. Keep organic matter up with compost, manure or crop residues.
Phosphorus deficiency in sorghum
Plants are stunted and thin, with dark green, stiff and upright leaves that take on a dark red or purple color, also on the leaf sheaths. Roots stay small and turn dark brown to black. Grain filling is poor. You see it most at this stage: seedling to early growth, with the loss showing later as poor heads.
Why phosphorus deficiency happens in batad
Acid soils, calcareous soils, soils low in organic matter, and cold or dry spells that slow the roots.
How to tell it apart
Potassium deficiency also brings red color but with dead patches on the leaf edges and tips. Magnesium gives stripes between the veins. To be sure, soil test for available phosphorus before planting, and look at the roots for small, dark root systems.
What to apply for phosphorus deficiency
For the standing crop, give 2 to 3 sprays of 2 percent DAP 18 46 0 (20 g per liter, 320 g in a 16 liter sprayer). For the next crop, place 16 20 0, Complete 14 14 14 or DAP in the furrow at planting, following the soil test. A usual basal dose is 2 to 4 bags of Complete 14 14 14 or Ammonium phosphate 16 20 0 per hectare, placed 5 cm beside and below the seed.
- Diammonium phosphate 18 46 0
- 16 20 0
- Complete 14 14 14
Sold here with phosphorus: Philphos 18 46 0 (Di Ammonium Phosphate), Atlas Super Gro (16 20 0) by Atlas Fertilizer, Amigo Planters Granular Single Super Phosphate by La Filipina (0 18 0 with 11 percent sulfur) and Triple Super Phosphate by Newman Chemicals (0 46 0). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to 16 20 0 fertilizer, and the page on phosphorus deficiency in every crop.
To keep it away, apply phosphorus at planting near the seed, and lime acid soils as the soil test says.
Potassium deficiency in sorghum
The older leaves show yellow then brown, dead tissue at the tips and edges, mixed with red specks and streaks between the veins. The damage moves from the tip and edge toward the leaf base. Stalks are weak. You see it most at this stage: mid growth to grain filling.
Why potassium deficiency happens in batad
Sandy and highly weathered soils, fields cropped for years without potash, and removal of stalks for fodder.
How to tell it apart
Nitrogen deficiency yellows the midrib first, while potassium burns the edges. Magnesium deficiency starts between the veins. To be sure, soil test for potassium and a look at where the browning starts on the bottom leaves.
What to apply for potassium deficiency
Give a 1 percent potassium chloride spray (10 g Muriate of potash per liter). For the soil, sidedress Muriate of potash 0 0 60 following the soil test. A usual dose is 1 to 2 bags of Muriate of potash 0 0 60 per hectare at planting or with the first side dress.
- Muriate of potash 0 0 60
- Complete 14 14 14
Sold here with potassium: Atlas Muriate of Potash (MOP) by Atlas Fertilizer (0 0 60), Simplot Sulfate 0 0 50 by Nutranta, Potassium Nitrate by Parafield (13 0 46) and Qrop Mix Production 14 0 23 plus 13 Cao by Farmtech Agriland (14 0 23 with 9.3 percent calcium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to potash fertilizer, and the page on potassium deficiency in every crop.
To keep it away, return stalks or ash to the field when they are not used for fodder, and include potash at planting on sandy soils. Keep organic matter up with compost, manure or crop residues. Split the potash on sandy soil.
Zinc deficiency in sorghum
New leaves come out evenly pale green, then white to pale yellow bands form in the lower half of the leaf and spread toward the tip. Leaf edges can show a clear red line and bleached white patches. Older leaves get yellow stripes between the veins and plants stay short. You see it most at this stage: seedling to early growth.
Why zinc deficiency happens in batad
High pH and calcareous soils, low organic matter and heavy phosphorus fertilizer on zinc poor soils.
How to tell it apart
Iron deficiency stripes the young leaves along their full length. Sulfur deficiency gives an even pale yellow with no bands. To be sure, soil test for zinc and pH, or a leaf test. In a soil test, less than 0.8 ppm of zinc is low.
What to apply for zinc deficiency
Give 20 to 25 kg Zinc sulfate per hectare to the soil, or a 0.5 percent zinc sulfate spray (5 g per liter, 80 g in a 16 liter sprayer). Give the soil dose at planting, and sprays 3 to 5 weeks after planting.
- Zinc sulfate
Sold here with zinc: Harvester Zinc Sulphate Heptahydrate by Universal Harvester (22 percent zinc), Petbowe Zinc Sulphate Monohydrate (33 percent zinc), Tierramino ZN by Unilox Far East Resources (7 0 0 with 10 percent zinc) and Liquid Chelate Zinc with Sulfur by Sagrex (10 percent zinc and 5 percent sulfur). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to fertilizer with zinc, and the page on zinc deficiency in every crop.
To keep it away, add zinc sulfate with the basal fertilizer on high pH soils. Test the soil every two or three years. Do not overdo phosphorus.
Iron deficiency in sorghum
The newest leaves turn pale yellow between the veins, which stay green, so the leaf looks striped along its whole length. In bad cases the leaves turn yellow to white and the crop looks bleached and dries. It shows in uneven patches that follow the soil, and it delays maturity. You see it most at this stage: the first 30 to 60 days. Plants often grow out of it in good weather.
Why iron deficiency happens in batad
Sorghum is very prone to it on high pH, calcareous soils with free lime and low organic matter, worse in drought or waterlogging.
How to tell it apart
A zinc shortage puts its pale bands on the lower half of the blade only. But these iron stripes run its full length. To be sure, soil pH test and a check for lime (fizzing with vinegar is a field hint). A leaf test for iron. In a soil test, less than 4.5 ppm of iron is low.
What to apply for iron deficiency
Give a 1 percent ferrous sulfate spray (10 g per liter, 160 g in a 16 liter sprayer) every week until new leaves are green, or 20 to 25 kg ferrous sulfate per hectare to the soil. Chelated iron (Fe EDDHA) at about 3.4 kg product per hectare in the furrow cuts the yellowing and raises yield. Give it at planting, or split it between planting and 2 weeks later.
- Ferrous sulfate
- Chelated iron (Fe EDDHA)
Sold here with iron: DDDD Planter's Choice Ferrous Sulphate Heptahydrate by Modern Time (19 percent iron), Ferrous Sulfate Monohydrate by Zetryl Chem (30 percent iron), Ferrous Sulphate Monohydrate by Newman Chemicals (30 percent iron) and Liquid Chelate Iron with Sulfur by Sagrex (5 percent iron and 3 percent sulfur). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to foliar fertilizer, and the page on iron deficiency in every crop.
To keep it away, choose tolerant hybrids for limey fields, add manure, and treat the first 30 days, which are the critical period. Test the soil every two or three years.
Sulfur deficiency in sorghum
The new upper leaves come out pale yellow, evenly over the leaf, and the veins do not stand out. There are no dead patches. Plants grow slowly. You see it most at this stage: early growth.
Why sulfur deficiency happens in batad
Sandy soils low in organic matter, heavy rain that washes sulfate down, and years of sulfur free fertilizer.
How to tell it apart
Nitrogen deficiency starts on the old leaves and dries the tips. Iron deficiency leaves green veins on the young leaves. To be sure, note that the youngest leaves are the palest. Test soil and leaves for sulfur. A soil test for sulfur and a leaf test confirm it.
What to apply for sulfur deficiency
Use Ammonium sulfate 21 0 0 for the sidedress nitrogen, or add Gypsum, following the soil test. A usual dose is 50 to 100 kg of Ammonium sulfate 21 0 0 per hectare (12 to 24 kg of sulfur), or 100 to 200 kg of Gypsum, at planting.
- Ammonium sulfate 21 0 0
- Gypsum
Sold here with sulfur: Atlas Ammosul 21 0 0 by Atlas Fertilizer (21 0 0 with 24 percent sulfur), Philphos Gypsum (22.2 percent calcium and 17.4 percent sulfur), Harvester Sulphate of Potash by Universal Harvester (0 0 50 with 17.5 percent sulfur) and Agsmart Kieserite Granule (20 percent sulfur and 16.3 percent magnesium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to ammonium sulfate fertilizer, and the page on sulfur deficiency in every crop.
To keep it away, include a sulfur source such as ammonium sulfate in the fertilizer plan on sandy soils. Keep organic matter up with compost, manure or crop residues.
Magnesium deficiency in sorghum
Older leaves turn dark yellow between the veins, then develop rusty brown dead spots, mostly at the tips and edges. Leaves can turn deep red, become brittle and die. You see it most at this stage: mid growth.
Why magnesium deficiency happens in batad
Acid, sandy soils in rainy areas and heavy potash on soils already low in magnesium.
How to tell it apart
Potassium deficiency browns the edges first, not between the veins. Iron deficiency hits young leaves. To be sure, soil test for magnesium and pH, and a leaf test.
What to apply for magnesium deficiency
Give a 2 percent magnesium sulfate spray (20 g Epsom salt per liter). On acid soils apply Dolomite following the soil test. A usual dose is 100 to 150 kg of Kieserite or 150 to 200 kg of Magnesium sulfate per hectare at planting. On acid soil, 1 to 2 tons of Dolomite mixed in before planting both limes and feeds.
- Epsom salt / magnesium sulfate
- Dolomite
Sold here with magnesium: Dolomite by A6 Agrisource (24 percent calcium and 11 percent magnesium), Agsmart Kieserite Granule (20 percent sulfur and 16.3 percent magnesium), DDDD Planter's Choice Magnesium Sulphate Monohydrate by Modern Time (15.1 percent magnesium) and Zetryl MAG 9 by Zetryl Chem (9 percent magnesium). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to complete fertilizer, and the page on magnesium deficiency in every crop.
To keep it away, lime acid soils with dolomite and keep potash balanced.
A soil test is the surest check for any sorghum nutrient deficiency. Before you buy, ask your Municipal Agriculture Office where to send a soil sample. The DA regional soil laboratories test soil, and the result says how much of each fertilizer your batad needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick batad, say where the leaves changed first and what you see, and get the fertilizers sold here that fix it.
- Anee, the smart farm technician, reads a photo of the leaf
- The cropping calendar dates every fertilizer application of your season
Sorghum nutrient deficiency questions
Why are my batad leaves turning yellow?
What fertilizer fixes nitrogen deficiency in sorghum?
What fertilizer fixes phosphorus deficiency in sorghum?
What fertilizer fixes potassium deficiency in sorghum?
How do I know which nutrient my batad lacks?
Find the missing nutrient and fix it
With Libre + Anee, read the whole guide: how to tell the deficiency from look alikes, how to be sure, what to apply, and the fertilizers sold here that supply it.
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