Banana Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Banana nutrient deficiency is one of the first things to check when the leaves of your saging (banana) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are potassium, nitrogen, magnesium, zinc, boron, calcium, phosphorus, sulfur, manganese and iron. 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? Potassium, nitrogen, magnesium and phosphorus move inside the plant, so a shortage shows on the old, lower leaves first. But zinc, boron, calcium, sulfur, manganese and iron 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 banana nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Banana nutrient deficiency signs, old leaves and young leaves
Shows first on the old leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Potassium | old, lower leaves, leaf edges and tips | Old leaves turn orange yellow from the tip, the edges scorch brown and the midrib bends. | Muriate of potash 0 0 60, Sulfate of potash 0 0 50 |
| Nitrogen | old, lower leaves, the whole plant | Pale green to yellow leaves, pinkish red leaf stalks and a thin, slow plant. | Urea 46 0 0, Ammonium sulfate 21 0 0 |
| Magnesium | old, lower leaves, between the veins | Old leaves yellow in the middle of the blade while the edge stays green. Purple blotches on the leaf stalk. | Magnesium sulfate (Epsom salt), Kieserite |
| Phosphorus | old, lower leaves, leaf edges and tips | Short plant with weak roots. Old leaf edges yellow in a saw tooth pattern and young leaves look bluish. | Ammonium phosphate 18 46 0, 16 20 0 |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Zinc | young leaves and the tip, between the veins | Young leaves narrow and pointed, with yellow and green stripes and a purple tint underneath. | Zinc sulfate |
| Boron | young leaves and the tip, fruit, grain or tubers | Young leaves curl and crumple, with white streaks across the veins on the underside. | Borax, Solubor |
| Calcium | young leaves and the tip, fruit, grain or tubers | New leaves come out as a spike with little or no blade. Ripe fruit peel splits. | Agricultural lime, Dolomite |
| Sulfur | young leaves and the tip, the whole plant | Young leaves even pale yellow, veins included, on a small slow plant. | Ammonium sulfate 21 0 0, 16 20 0 |
| Manganese | young leaves and the tip, leaf edges and tips | The second or third youngest leaf yellows from the edge inward along the veins, like the teeth of a comb. | Manganese sulfate |
| Iron | young leaves and the tip, between the veins | Young leaves turn yellow to almost white while the veins stay green for a while. | Ferrous sulfate, Urea 46 0 0 |
Before you buy fertilizer for a banana nutrient deficiency
So use the table to pick the likeliest banana 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.
Potassium deficiency in banana
The oldest leaves yellow first, starting at the leaf tip and between the veins. The yellow turns orange, the patches join, and the tissue dries dark brown, often as a scorch along the edges. Leaves get smaller, may split along the side veins, and the midrib can bend and break. Bunches come late and stay short and thin, with small fingers that fill poorly. You see it most at this stage: any age, but worst from the fast leaf growth stage to bunch filling, when the plant takes up the most potash.
Why potassium deficiency happens in saging
Sandy or light soils, acid soils and heavy rain that washes potash away. Soils already rich in magnesium, which hold back potash uptake. Long dry spells also cut uptake.
How to tell it apart
Magnesium deficiency also starts on old leaves. But the yellow band sits between the midrib and the edge while the edge stays green. To be sure, send a leaf sample and a soil sample to a lab. A soil test that shows low potash, or a high magnesium to potash balance, points to this. Bunches that fill better after potash is added confirm it.
What to apply for potassium deficiency
Apply Muriate of potash 0 0 60 to the soil around the mat, split into several doses, following the soil test. While the soil dose takes effect, spray the leaves with Sulfate of potash at 1 percent (10 grams per liter, 160 grams in a 16 liter sprayer). Keep the soil pH above 6 with lime or dolomite on acid soils. Give 200 to 300 grams of Muriate of potash 0 0 60 a mat every two to three months, more as the bunch forms.
- Muriate of potash 0 0 60
- Sulfate of potash 0 0 50
- Complete 14 14 14
- Dolomite
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. 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, give potash every cycle, in splits, from the early vegetative stage up to bunch emergence. Return chopped leaves and pseudostems to the mat. Keep organic matter up with compost, manure or crop residues.
Nitrogen deficiency in banana
The oldest leaves go light green, then yellow, and the veins do not stay green. Leaf stalks, midribs and leaf sheaths take on a pink to reddish color. The pseudostem stays thin, new leaves are small and come slowly, and leaves may crowd together. Bunch weight and fruit quality drop. You see it most at this stage: from early growth to bunch emergence, most often in fast growing young plants.
Why nitrogen deficiency happens in saging
Sandy soils with little organic matter, heavy rain or irrigation that washes nitrogen down. Fresh straw or raw manure that ties up nitrogen as it rots. Roots damaged by nematodes or weevils also take up less.
How to tell it apart
Sulfur deficiency also gives light green to yellow leaves, but it starts on the young leaves. Iron deficiency starts on young leaves and keeps the midrib and veins green for a while. To be sure, A leaf test shows low nitrogen. Check that the roots are healthy. New leaves that green up within a few weeks after urea confirm it.
What to apply for nitrogen deficiency
Apply Urea 46 0 0 or Ammonium sulfate 21 0 0 around the mat and water it in. Give 300 grams of Urea per plant, then irrigate. Split it into smaller doses on sandy soil. Add compost or well rotted manure to build the soil.
- 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), Hyfer Urea Max (Locally Blended Coated) by Agrotiger (44 0 0) 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.
To keep it away, split nitrogen through the crop, from the third month up to bunch emergence. Keep a mulch of old leaves on the mat. Let a soil test and the crop's color set the season's nitrogen.
Magnesium deficiency in banana
Old leaves yellow in the middle part of the blade, along the midrib, while the leaf edge stays green. Dead spots form inside the yellow parts. The leaf stalk shows bluish purple mottling, and leaf sheaths may pull away from the pseudostem. Bunch weight and yield fall. You see it most at this stage: mostly on older plants and after heavy potash feeding, during the vegetative stage and bunch filling.
Why magnesium deficiency happens in saging
Sandy and acid soils, and heavy use of potash, which competes with magnesium. Cold, wet spells make it worse. The opposite also happens on some plantations: soil very high in magnesium crowds out potash and calcium.
How to tell it apart
Potassium deficiency also hits old leaves, but it starts at the tip and edge as an orange scorch. Manganese deficiency looks similar but starts on young leaves. To be sure, do a soil test for magnesium, potash and calcium together, since the balance matters, and a leaf test. Purple mottled leaf stalks with green leaf edges are a strong field sign.
What to apply for magnesium deficiency
Apply Magnesium sulfate (Epsom salt) or Kieserite around the mat and water it in. Give 25 grams of Magnesium sulfate per plant. On acid soils use Dolomite, which gives both lime and magnesium. Do not put magnesium and potash fertilizer down on the same day. Put the soil dose in before planting or when the rains begin. Sprays show results in 10 to 14 days.
- Magnesium sulfate (Epsom salt)
- Kieserite
- 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), Magnesium Sulphate Anhydrous by Newman Chemicals (20 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, base potash and magnesium on a soil test so one does not crowd out the other. Use dolomite instead of plain lime on acid soils.
Zinc deficiency in banana
Young leaves come out smaller and more lance shaped, with yellow to white stripes between the side veins that give a striped, mottled look. The underside of the rolled new leaf shows a strong purple tint. Leaves may crowd into a rosette. Bunches are small and the fingers short, thin, twisted and light green at the tip. You see it most at this stage: on young plants and suckers, and in later cycles. Losses often show in the second or third year.
Why zinc deficiency happens in saging
High pH or limed soils, organic soils, heavy phosphorus fertilizer, and cold wet weather. It is the most common micronutrient shortage in banana.
How to tell it apart
Bunchy top virus also gives narrow, bunched leaves. But it shows dark green dot and dash streaks along the veins and leaf stalk and the leaves stand stiff and upright. To be sure, A leaf test for zinc and a soil test for pH and phosphorus. Spray a few plants with zinc sulfate. New leaves that come out normal confirm it.
What to apply for zinc deficiency
Spray Zinc sulfate on the leaves. Use 5 grams per liter (80 grams in a 16 liter sprayer) (0.5 percent), or 2 grams per liter (32 grams in a 16 liter sprayer) plus 2.5 grams of lime per liter on young leaves. On poor soils also apply Zinc sulfate to the soil, following the soil test. Do not apply it on the same day as phosphate fertilizer. A usual soil dose is 20 to 25 kg of Zinc sulfate per hectare (about 5 kg of zinc), mixed with the basal fertilizer. It lasts two or three crops.
- Zinc sulfate
Sold here with zinc: Harvester Zinc Sulphate Heptahydrate by Universal Harvester (22 percent zinc), Tierramino ZN by Unilox Far East Resources (7 0 0 with 10 percent zinc), Liquid Chelate Zinc with Sulfur by Sagrex (10 percent zinc and 5 percent sulfur) and Nemes Foliar by SCL Filipinas (4.8 0 0 with 10 percent zinc, 4.9 percent boron and 4.8 percent magnesium). 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, avoid overliming and very heavy phosphorus. Include zinc in the program on soils that tested low.
Boron deficiency in banana
The youngest leaves show it. Leaf edges go pale and curl inward, then brown. White streaks run across the veins on the underside, the side veins thicken, and the blade can be crumpled, misshapen or missing. Plants may be stunted with leaves bunched in a fan. Bunches are light, poorly filled or deformed. You see it most at this stage: during fast leaf growth and around flowering, often after a dry spell.
Why boron deficiency happens in saging
Sandy or alkaline soils low in organic matter, drought, and very high nitrogen or calcium. Cold wet spells can also bring it on.
How to tell it apart
Calcium deficiency also damages young leaves, but its dead tissue is lighter brown and starts at the tip. The side veins thicken more. To be sure, A leaf test for boron, and a soil test. New leaves that come out normal after a light boron dose confirm it. In a soil test, less than 0.5 ppm of boron is low.
What to apply for boron deficiency
Apply Borax to the soil around the root zone. Give 25 grams per plant. A foliar spray of Borax at 1 gram per liter (16 grams in a 16 liter sprayer) also works. Boron is toxic in excess, so do not repeat high doses without a test. Give boron before flowering: flowers and fruit set need it most.
- Borax
- Solubor
Sold here with boron: Borax Decahydrate by Parafield (10.5 percent boron), Etifert 15 (Borax Pentahydrate) by Zetryl Chem (15 percent boron), B17 (Boric Acid) by Newman Chemicals (17 percent boron) and Better Yield by Bacphil Planters Fertilizer (0 0 0.9 with 10 percent boron). 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 boron deficiency in every crop.
To keep it away, keep organic matter up and water during dry spells. Add a small boron dose on soils that tested low. Test the soil every two or three years.
Calcium deficiency in banana
Young leaves fail to open fully, giving a 'spike leaf' with a deformed or missing blade. Leaves pale, then die back light brown from the tip, with thick side veins. Roots are short and thick. The peel splits as fruit ripens, fingers curl, and weak fruit tips let cigar end rot in. You see it most at this stage: during fast growth and fruit formation.
Why calcium deficiency happens in saging
Acid soils, sandy soils that leach, soils high in sodium or aluminum, drought, and heavy potash or nitrogen that pushes calcium out.
How to tell it apart
Boron deficiency also hurts young leaves, but its dead tissue is darker and starts at the leaf edge with white streaks under the leaf. Virus and herbicide damage can also deform new leaves. To be sure, soil test for pH and calcium, and a leaf test. Low pH with spike leaves points to calcium.
What to apply for calcium deficiency
On acid soils apply Agricultural lime or Dolomite to the mat, following the soil test. Rates run from 50 grams to 1 kg of lime per plant, split over the year. On soils with normal pH use Gypsum or Calcium nitrate. Do not overload potash.
- Agricultural lime
- Dolomite
- Gypsum
- Calcium nitrate
Sold here with calcium: Planters Products Lifelime (36.2 percent calcium), Dolomite by A6 Agrisource (24 percent calcium and 11 percent magnesium), Calcipro by Ramgo (15.5 0 0 with 18.8 percent calcium) and Philphos Gypsum (22.2 percent calcium and 17.4 percent sulfur). Check the FPA registration on the bag and follow the label rate. For the how and when, see our guide to fertilizer for tomatoes, and the page on calcium deficiency in every crop.
To keep it away, lime acid soils before planting, keep water steady, and keep potash and calcium in balance.
Phosphorus deficiency in banana
Growth is slow and the plant stays short, with a thin, woody pseudostem and weak roots. The edges of old leaves yellow in a saw tooth pattern with purplish brown flecks, then die, and the leaves curl. Leaf stalks break easily. Young leaves look dark bluish green, sometimes purple underneath. You see it most at this stage: early growth, right after planting and in young suckers.
Why phosphorus deficiency happens in saging
Acid soils that lock up phosphorus, very alkaline soils, low organic matter, cold or waterlogged soil, and poor roots.
How to tell it apart
Too much nitrogen also gives dark blue green leaves. Manganese deficiency also kills leaf edges, but its dead areas are darker and it starts on younger leaves. To be sure, soil test for available phosphorus and pH, and a leaf test.
What to apply for phosphorus deficiency
Apply a phosphorus fertilizer near the roots and water it in. Give 50 grams of DAP (Ammonium phosphate 18 46 0) per plant. On acid soils correct the pH with lime so the phosphorus stays available. Give it at planting and every three months.
- Ammonium phosphate 18 46 0
- 16 20 0
- Complete 14 14 14
- Superphosphate 0 20 0
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, put phosphorus in the planting hole and in the first months, and lime acid soils. Test the soil every two or three years.
Sulfur deficiency in banana
Young leaves turn light green to yellowish white, evenly over the whole leaf, veins included. New leaves are small and the side veins can look thick, and in bad cases the edges die. The plant grows slowly and bunches stay small or get stuck in the throat. You see it most at this stage: during fast vegetative growth.
Why sulfur deficiency happens in saging
Acid, sandy soils that leach, low organic matter, waterlogged soils. Years of using only urea and muriate of potash with no sulfur.
How to tell it apart
Nitrogen deficiency looks the same but starts on old leaves. Iron deficiency also hits young leaves, but it is patchy and keeps green areas near the midrib. To be sure, leaf test for sulfur and a soil test. Plants that green up after a sulfur fertilizer confirm it. In a soil test, less than 10 ppm of sulfate sulfur is low.
What to apply for sulfur deficiency
Use a nitrogen or phosphorus fertilizer that carries sulfur, such as Ammonium sulfate 21 0 0 or 16 20 0, in place of part of the urea. Give 20 grams per plant of a complex fertilizer that carries sulfur. Gypsum also supplies sulfur. Give it at planting or with the first side dress.
- Ammonium sulfate 21 0 0
- 16 20 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, use ammonium sulfate or 16 20 0 for part of the nitrogen every cycle. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Manganese deficiency in banana
It shows first on the second or third youngest leaf. Mild cases are just light green. Then yellow starts at the leaf edge and runs in along the veins toward the midrib, giving a comb tooth pattern. In bad cases the yellow areas die and the edges curl down. You see it most at this stage: during fast growth, more often in cool wet months.
Why manganese deficiency happens in saging
High pH or limed soils, sandy soils, organic soils, and cold wet periods.
How to tell it apart
Magnesium deficiency looks similar but starts on old leaves. Iron deficiency yellows the whole young leaf without the comb tooth pattern or dead areas. To be sure, leaf test for manganese and soil test for pH. Test spray a few plants. In a soil test, less than 1 ppm of manganese is low.
What to apply for manganese deficiency
Spray Manganese sulfate on the leaves at 0.5 percent (5 grams per liter, 80 grams in a 16 liter sprayer). Repeat if new leaves still show it. Spray the young leaves in the cool of the day, soon after sunrise or near sunset.
- Manganese sulfate
Sold here with manganese: Manganese Sulfate by Zetryl Chem (31 percent manganese), Tierramino MN by Unilox Far East Resources (7 0 0 with 12 percent manganese), Multimate by Agway (4 0 0 with 4.5 percent sulfur, 2.8 percent zinc and 1.8 percent manganese) and Nutri Tabble Meta Foliar by NS Northern Organic Fertilizer (12 percent zinc, 9 percent sulfur, 2 percent magnesium and 1.2 percent manganese). 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 manganese deficiency in every crop.
To keep it away, avoid overliming. On high pH soils include manganese in the foliar program. Test the soil every two or three years.
Iron deficiency in banana
Young leaves turn yellowish green, then yellow or nearly white. The yellow starts between the veins near the base and edges and spreads to the tip, giving a mottled look. The midrib and veins stay green longer but fade in bad cases. Growth slows and bunches stay small. You see it most at this stage: young plants and new leaves, especially after flooding.
Why iron deficiency happens in saging
High pH and limey soils, waterlogged soils, and too much copper, manganese or zinc.
How to tell it apart
Sulfur deficiency also yellows young leaves, but evenly with no green veins. Nitrogen deficiency starts on old leaves. To be sure, soil test for pH and check drainage. A test spray of iron on a few plants that greens the new leaves confirms it. Leaf iron numbers alone are not reliable.
What to apply for iron deficiency
Spray Ferrous sulfate at 0.5 percent (5 grams per liter, 80 grams in a 16 liter sprayer) mixed with Urea at 1 percent (10 grams per liter, 160 grams in a 16 liter sprayer). Improve drainage where water stands. Spray the young leaves in the cool of the day, soon after sunrise or near sunset.
- Ferrous sulfate
- Urea 46 0 0
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, drain wet spots and avoid overliming. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
A soil test is the surest check for any banana 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 saging needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick saging, 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
Banana nutrient deficiency questions
Why are my saging leaves turning yellow?
What fertilizer fixes potassium deficiency in banana?
What fertilizer fixes nitrogen deficiency in banana?
What fertilizer fixes magnesium deficiency in banana?
How do I know which nutrient my saging lacks?
- Yara Philippines: Potassium deficiency in banana
- Haifa: Crop guide, banana fertilizer (deficiency symptoms)
- Salibay and Salomez 2009, Banana fertilization at the plantation: soil and leaf analysis results (Davao del Norte)
- Yara Philippines: Nitrogen deficiency in banana
- Yara Philippines: Magnesium deficiency in banana
- Yara Philippines: Zinc deficiency in banana
- Yara Philippines: Boron deficiency in banana
- Yara Philippines: Calcium deficiency in banana
- Yara Philippines: Phosphorus deficiency in banana
- Yara Philippines: Sulfur deficiency in banana
- Yara Philippines: Manganese deficiency in banana
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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