Coconut Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Coconut nutrient deficiency is one of the first things to check when the leaves of your niyog (coconut) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, potassium, sulfur, boron, magnesium, phosphorus and manganese. 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, potassium, magnesium and phosphorus move inside the plant, so a shortage shows on the old, lower leaves first. But sulfur, boron and manganese 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 coconut nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Coconut 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 | The whole crown is pale yellow green, the fronds taper, and few palms bear nuts. | Ammonium sulfate 21 0 0, Urea 46 0 0 |
| Potassium | old, lower leaves, leaf edges and tips | Old fronds show see through yellow to orange spots near the tips, then dead leaflet edges. | Muriate of potash 0 0 60, Ammonium sulfate 21 0 0 |
| Magnesium | old, lower leaves, leaf edges and tips | Old fronds show a wide yellow band along the leaflet edges while the centre stays green. | Kieserite, Magnesium sulfate (Epsom salt) |
| Phosphorus | old, lower leaves | Old fronds dark or purplish green, small fronds, and flowering comes late. | Superphosphate 0 20 0, Ammonium phosphate 18 46 0 |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Sulfur | old, lower leaves, the whole plant | Fronds pale yellow to orange, fewer nuts, and copra that comes out rubbery and shrunken. | Ammonium sulfate 21 0 0, Gypsum |
| Boron | young leaves and the tip, fruit, grain or tubers | New fronds stay crinkled and unopened, leaflet tips hook, and young nuts (buttons) fall. | Borax, Solubor |
| Manganese | young leaves and the tip, between the veins | New fronds come out yellow with dead streaks, then wither and frizzle. Leaflet tips drop off. | Manganese sulfate |
Before you buy fertilizer for a coconut nutrient deficiency
So use the table to pick the likeliest coconut 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 coconut
The oldest fronds turn an even light green to yellow first. The yellow moves up until the whole crown is pale except the spear. Fronds look tapered and new ones come slowly. Few palms flower, and those that do set few nuts with thin meat and low copra. You see it most at this stage: any age. Very common in old, unfertilized bearing palms.
Why nitrogen deficiency happens in niyog
Most coconut soils here run short of nitrogen. Palms that never get fertilizer, weedy rings, and sandy soils show it most.
How to tell it apart
Sulfur deficiency gives the same even yellowing and often comes together with it. Chloride shortage also yellows old fronds early. To be sure, send a leaf test of frond number 14. Take the middle part of 24 leaflets from the middle of that frond. A clear greening within a year after ammonium sulfate confirms it.
What to apply for nitrogen deficiency
Apply Ammonium sulfate 21 0 0 in a ring around the palm after weeding. Give each palm 1.5 to 2 kg Ammonium sulfate and 2 kg Muriate of potash yearly, in two equal splits. Palms fed this way give the most nuts and copra. About 0.66 kg Urea did about as well as the ammonium sulfate. Ammonium sulfate also supplies sulfur. Give 0.5 to 1 kg of Ammonium sulfate 21 0 0 or Urea 46 0 0 a palm a year, in two doses: when the rains begin and before they end.
- Ammonium sulfate 21 0 0
- Urea 46 0 0
- Muriate of potash 0 0 60
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, fertilize every year, split in two at the start and end of the rainy season, and keep the ring weeded. Legume cover crops help a little but do not replace fertilizer. Let a soil test and the crop's color set the season's nitrogen.
Potassium deficiency in coconut
The oldest fronds show small, see through yellow or orange spots, first near the leaflet tips. Later the leaflet edges and tips dry brown, and the old fronds die early. In bad cases only a few live fronds remain and the trunk narrows to a pencil point. Nuts are smaller, with thin shells, less water and lower copra. You see it most at this stage: bearing palms, and palms on sandy soils under heavy rain.
Why potassium deficiency happens in niyog
Sandy and coral soils, heavy rain that leaches potash, and heavy nitrogen without potash. Salt fertilizer alone can make it worse because sodium competes with potash.
How to tell it apart
Magnesium deficiency also starts on old fronds. But as a broad yellow band on the leaflet edges with a green centre and no spots. To be sure, leaf test of frond number 14, and a soil test for potash.
What to apply for potassium deficiency
Apply Muriate of potash 0 0 60 in the weeded ring. Give 2 kg per palm each year in two splits, along with ammonium sulfate. Inland palms in many provinces are also short of chloride. Use common salt at 1.5 kg per bearing palm per year. On low potash soils salt should go with potash, not replace it.
- Muriate of potash 0 0 60
- Ammonium sulfate 21 0 0
- Common salt (sodium chloride)
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, give potash every year in two splits, and return husks and fronds to the ring. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Sulfur deficiency in coconut
Leaflets turn from dark green to yellowish orange, most of all on the older, lower fronds, and dry early. The yellowing can spread to younger fronds, which stay thin and brittle. Nut numbers drop, and the copra is rubbery and shrunken instead of white and thick. You see it most at this stage: bearing palms.
Why sulfur deficiency happens in niyog
Sulfur is one of the widespread shortages in Philippine coconut soils. Palms fed only urea and muriate of potash, with no sulfur source, show it most.
How to tell it apart
Nitrogen deficiency gives the same pale crown. The two often come together, which is why ammonium sulfate works so well on coconut. To be sure, leaf test of frond number 14 for sulfur. Leaf sulfur rises and falls closely with yield. In a soil test, less than 10 ppm of sulfate sulfur is low.
What to apply for sulfur deficiency
Use Ammonium sulfate 21 0 0 as the nitrogen source, or apply Gypsum. Gypsum at 0.75 kg per palm a year pays best, and about 2.5 kg gives the most nuts. Treated palms gave whiter, thicker copra. Give it at planting or with the first side dress.
- 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, keep a sulfur source such as ammonium sulfate or gypsum in the yearly program. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Boron deficiency in coconut
Only the young fronds show it. Leaflets stay fused and fail to split or open, tips bend into a hook. Fronds come out small, crinkled, zigzag or with no leaflets at all. New leaves crowd at the top and choke the crown, and in bad cases the bud blackens and the palm dies. Bearing palms shed many buttons, flower clusters abort or carry few female flowers, and some nuts crack or have little meat. You see it most at this stage: young palms in the field, and bearing palms after a long dry season.
Why boron deficiency happens in niyog
Sandy and inland soils, dry months with less than about 75 mm of rain, heavy liming, and heavy potash or salt rates. It turns up often on young plantings.
How to tell it apart
Button shedding also comes from drought, poor pollination, pests and other nutrient shortages, so look at the young fronds too. Bud rot also kills the spear, but the spear rots and smells, and the fronds do not show hooks or fused leaflets. To be sure, look for hooked, fused or unopened leaflets on the newest fronds. A leaf test and a soil test for boron help. A low reading warns of trouble even before signs appear.
What to apply for boron deficiency
Apply Borax in the ring around the palm, split in two doses with the other fertilizer. Give 300 grams of borax per young palm and 500 grams per adult palm each year. Damaged fronds stay misshapen, but new fronds come out normal after six to ten months. Give 50 to 100 grams of Borax a palm a year, in a ring with the other fertilizer.
- Borax
- Solubor
Sold here with boron: Etifert 11 (Borax Decahydrate) by Zetryl Chem (11 percent boron), Fertibagra 15G by Unilox Far East Resources (14.6 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, on sandy or inland soils add a small yearly boron dose, avoid heavy liming, and water young palms in the dry season. Too much boron is toxic, so test first. Test the soil every two or three years.
Magnesium deficiency in coconut
The oldest fronds yellow first, as broad bands along the leaflet edges while the centre near the midrib stays green. Younger fronds show less and less of it. In bad cases the leaflet tips die reddish brown and fruit set drops. You see it most at this stage: bearing palms, often after years of heavy potash.
Why magnesium deficiency happens in niyog
Sandy, leached soils, and heavy nitrogen, potash or lime, which push magnesium out. Many coconut farms here are short of magnesium.
How to tell it apart
Potassium deficiency also starts on old fronds. But it shows see through orange spots and dead tips, not a clean yellow edge band. To be sure, leaf test of frond number 14, and a soil test for magnesium, potash and calcium.
What to apply for magnesium deficiency
Apply Kieserite or Magnesium sulfate in the ring, following the soil test. On acid soils Dolomite supplies magnesium and lime together. Do not put magnesium and potash down on the same day. Give 0.5 to 1 kg of Kieserite or Magnesium sulfate a palm a year, or Dolomite on acid soil. Put the soil dose in before planting or when the rains begin. Sprays show results in 10 to 14 days.
- Kieserite
- Magnesium sulfate (Epsom salt)
- 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, balance potash with magnesium, and use dolomite instead of plain lime on acid soils.
Phosphorus deficiency in coconut
Older, lower fronds show it first. In bad cases they turn dark green or purplish and drop early. Fronds stay smaller than normal, roots are weak, and flowering and fruiting come late. You see it most at this stage: seedlings and young palms most. Less common in bearing palms.
Why phosphorus deficiency happens in niyog
Very acid soils that lock up phosphorus and soils low in organic matter. It is less common in coconut than nitrogen or potash shortage.
How to tell it apart
Nitrogen deficiency makes old fronds pale, not dark. Drought and root damage also slow growth, so check the soil and roots. To be sure, soil test for available phosphorus and pH, and a leaf test of frond number 14.
What to apply for phosphorus deficiency
Apply a phosphorus fertilizer in the ring, following the soil test. Superphosphate acts quickly. Rock phosphate and bone meal work slowly over years. Phosphorus is most available near pH 6.5 to 7.5, so lime very acid soils. Give 0.5 to 1 kg of single superphosphate 0 18 0 or rock phosphate a palm a year. Give it when the rains begin.
- Superphosphate 0 20 0
- Ammonium phosphate 18 46 0
- Complete 14 14 14
- Rock phosphate
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 years, and add compost or manure.
Manganese deficiency in coconut
The newest fronds come out yellow with dead streaks along or between the veins, worst near the base. New leaflets wither and curl, giving a frizzled top. On coconut the dead leaflet tips fall off so the crown looks singed. In bad cases growth stops and the bud dies. You see it most at this stage: any age, on high pH soils.
Why manganese deficiency happens in niyog
High pH soils such as coral and limestone soils near the coast, cold soils. Heavy manure or compost that ties up manganese.
How to tell it apart
Iron deficiency also yellows new fronds but without the dead streaks and frizzled leaflets. Boron deficiency also deforms new fronds, but with hooked and fused leaflets. To be sure, soil test for pH, and a leaf test for manganese. In a soil test, less than 1 ppm of manganese is low.
What to apply for manganese deficiency
Spray Manganese sulfate on the fronds at 5 grams per liter (80 grams in a 16 liter sprayer), or apply it to the soil, following the soil test. Use the sulfate form. 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, on coral and limestone soils include manganese in the program and avoid adding more lime.
A soil test is the surest check for any coconut 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 niyog needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick niyog, 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
Coconut nutrient deficiency questions
Why are my niyog leaves turning yellow?
What fertilizer fixes nitrogen deficiency in coconut?
What fertilizer fixes potassium deficiency in coconut?
What fertilizer fixes sulfur deficiency in coconut?
How do I know which nutrient my niyog lacks?
- Baliad, Effects of organic and inorganic nitrogen on coconut on three soil types in Leyte, Philippines (CORD)
- Magat 1997, Coconut yield improvement in farmers' fields through research based fertilization in the Philippines (CORD)
- UH CTAHR SCM 36: Salt fertilization for coconut palms in Hawaii
- U.S. Borax crop guide: Boron deficiency in coconut
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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