Rambutan Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Rambutan nutrient deficiency is one of the first things to check when the leaves of your rambutan turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, potassium, phosphorus, zinc 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, potassium, phosphorus and magnesium move inside the plant, so a shortage shows on the old, lower leaves first. But zinc 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 rambutan nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Rambutan 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 canopy, yellow older leaves that drop, and weak, short flushes after harvest. | Complete 14 14 14, 16 20 0 |
| Potassium | old, lower leaves, leaf edges and tips | Older leaflets scorch brown at the edges. Fruits stay small and less sweet. | Sulfate of potash 0 0 50, Muriate of potash 0 0 60 |
| Phosphorus | old, lower leaves | Slow growth, dull older leaves with a purple or bronze tint underneath, and weak flowering. | 16 20 0, Complete 14 14 14 |
| Magnesium | old, lower leaves, between the veins | Older leaflets yellow between green veins. In bad cases lower leaves drop. | Dolomite, Magnesium sulfate (Epsom salt) |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Zinc | young leaves and the tip, between the veins | New leaflets small, narrow and bunched, yellow between the veins. Few, short flower panicles. | Zinc sulfate |
Before you buy fertilizer for a rambutan nutrient deficiency
So use the table to pick the likeliest rambutan 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 rambutan
The canopy turns light green, then the older leaves yellow evenly and drop, and the yellowing moves up. New flushes after harvest come out short with small leaves, so the tree has less leaf to carry the next crop. You see it most at this stage: after harvest, when the tree should flush, and in young trees.
Why nitrogen deficiency happens in rambutan
Rambutan removes a lot of nitrogen with its fruit and the twigs cut at harvest. Trees fed only organic matter or nothing at all, sandy soils and heavy rain show it most.
How to tell it apart
Glyphosate sprayed under the canopy edge causes severe yellowing and drop of lower leaves. Ask what was sprayed. To be sure, leaf test of the newest leaflets that have fully matured at the branch ends, taken before flowering. Healthy leaves hold 2.0 to 2.5 percent nitrogen.
What to apply for nitrogen deficiency
For young trees in the third and fourth year, give 1 to 2 kg of complete fertilizer per tree with 300 grams of Muriate of potash. For bearing trees it gives 25 kg of organic fertilizer per tree after ring weeding, then 2 to 3 kg of Complete 14 14 14 or 16 20 0 one to two months later. Give about 200 grams of nitrogen per tree for each year of age, up to 12 years, with half of the yearly amount right after harvest. Too much nitrogen can delay flowering and make fruit drop.
- Complete 14 14 14
- 16 20 0
- Urea 46 0 0
- Ammonium sulfate 21 0 0
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, feed the tree right after harvest to push a good flush, and return pruned twigs and leaves as mulch. Let a soil test and the crop's color set the season's nitrogen. Split the nitrogen into two or three doses.
Potassium deficiency in rambutan
Edges and tips of older leaflets yellow, then dry brown, and the scorch moves inward. Fruit set is poorer and fruits stay small and less sweet. You see it most at this stage: fruit growth, when the crop pulls the most potash.
Why potassium deficiency happens in rambutan
Rambutan removes a lot of potassium with its fruit. Leached, sandy soils under heavy rain, and trees fed mostly nitrogen, show it most.
How to tell it apart
Rambutan is very sensitive to chloride. Burnt leaf edges and leaf drop mostly come from too much chloride, such as from Muriate of potash. To be sure, leaf test of the newest leaflets that have fully matured at the branch ends before flowering, for both potassium and chloride. Healthy leaves hold 0.7 to 0.9 percent potassium and under 0.2 percent chloride.
What to apply for potassium deficiency
Give 300 grams of Muriate of potash with the complete fertilizer before flowering. A second potash dose in water during fruit growth for bigger, sweeter fruit. Rambutan dislikes chloride, so Sulfate of potash or potassium nitrate is the better choice. Switch to those where leaf edges burn. Give about 130 grams of potash per tree for each year of age for fruiting trees, up to 12 years.
- Sulfate of potash 0 0 50
- 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, split potash between before flowering and fruit growth, and choose a chloride free source on trees that show edge burn. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Phosphorus deficiency in rambutan
The tree grows slowly and stays stunted, and older leaves turn dull with a purple or bronze tint, mostly underneath. Flowering is weak. You see it most at this stage: young trees, and the weeks before flowering in bearing trees.
Why phosphorus deficiency happens in rambutan
Very acid soils that hold phosphorus tightly, and soils low in organic matter. Rambutan needs less phosphorus than nitrogen and potash, yet some trees still test below the suggested leaf range.
How to tell it apart
Drought, cold and root damage can also slow growth and tint leaves. Nitrogen deficiency gives pale yellow, not purple, old leaves. To be sure, leaf test of the newest leaflets that have fully matured at the branch ends before flowering. Healthy leaves hold 0.2 to 0.3 percent phosphorus. A soil test for available phosphorus and pH.
What to apply for phosphorus deficiency
Use Complete 14 14 14 or 16 20 0 before flowering, which supply phosphorus. After the last flush matures, spray monopotassium phosphate at 5 grams per liter (80 grams in a 16 liter sprayer) three times, a week apart. Then give a 7 13 34 foliar feed with zinc for the most flowers, about 10 days earlier. Follow the soil test and lime very acid soils. Give 200 to 500 grams of Complete 14 14 14 a young tree, up to 1 to 2 kg a bearing tree, when the rains begin.
- 16 20 0
- Complete 14 14 14
- Superphosphate 0 20 0
- Monopotassium phosphate 0 52 34
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 and compost in the planting hole and keep some in the yearly program.
Zinc deficiency in rambutan
New leaflets are small and narrow, yellow between the veins, and crowd at the shoot tip. Trees with more leaf zinc make more flower panicles on each shoot. So a shortage shows up as weak flowering and fewer fruits. You see it most at this stage: the last flush before flowering, and flowering.
Why zinc deficiency happens in rambutan
Sandy or eroded soils, high pH or overlimed soils, and heavy phosphate fertilizer. Leaf tests find some orchards below the suggested zinc range.
How to tell it apart
Iron and manganese deficiency also yellow young leaves between the veins, but the leaves keep their size. Mites and thrips can stunt and curl new leaves. To be sure, leaf test of the newest leaflets that have fully matured at the branch ends before flowering. Healthy leaves hold 30 to 35 ppm zinc. Spray a few branches and compare the next flush.
What to apply for zinc deficiency
Spray zinc on the mature last flush before flowering. For the biggest panicles, spray a 7 13 34 foliar fertilizer with zinc at 1.5 grams of product per liter (24 grams in a 16 liter sprayer), three times a week apart. Zinc sulfate also works. Sprays for other fruit trees use 3 to 5 grams Zinc sulfate per liter. Follow the label. Give 50 to 100 grams of Zinc sulfate a young tree and 100 to 250 grams a bearing tree a year under the canopy.
- 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 very heavy phosphate and overliming, and check leaf zinc every few years. Test the soil every two or three years.
Magnesium deficiency in rambutan
Older leaflets yellow between the veins while the veins stay dark green. In bad cases growth slows, new leaves are smaller and lower leaves drop. You see it most at this stage: bearing trees, often during and after fruit growth.
Why magnesium deficiency happens in rambutan
Acid, leached soils and heavy potash fertilizer, which competes with magnesium. Some orchards test below the suggested leaf magnesium range.
How to tell it apart
Potassium shortage or chloride burn scorches the leaf edges brown rather than yellowing between the veins. Nitrogen deficiency yellows the whole old leaf, veins included. To be sure, leaf test of the newest leaflets that have fully matured at the branch ends before flowering. Healthy leaves hold 0.25 to 0.35 percent magnesium. A soil test for magnesium, potassium and calcium.
What to apply for magnesium deficiency
Give Dolomite at 0.4 kg per tree for each year of age, up to 10 years, applied in the slow growing months. Where the soil pH is already fine, use Magnesium sulfate or Kieserite, following the soil test.
- Dolomite
- Magnesium sulfate (Epsom salt)
- Kieserite
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, use Dolomite when liming and keep potash and magnesium in balance.
A soil test is the surest check for any rambutan 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 rambutan needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick rambutan, 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
Rambutan nutrient deficiency questions
Why are my rambutan leaves turning yellow?
What fertilizer fixes nitrogen deficiency in rambutan?
What fertilizer fixes potassium deficiency in rambutan?
What fertilizer fixes phosphorus deficiency in rambutan?
How do I know which nutrient my rambutan 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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