Santol Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Santol nutrient deficiency is one of the first things to check when the leaves of your santol turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, potassium, phosphorus and zinc. 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 and phosphorus 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 santol nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Santol 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 | A pale, light green tree with yellowing older leaves, short new shoots and a light crop. | Ammonium sulfate 21 0 0, Complete 14 14 14 |
| Potassium | old, lower leaves, leaf edges and tips | Older leaflets scorch brown along the edges and tips. Fruits stay small and poor. | Complete 14 14 14, Muriate of potash 0 0 60 |
| Phosphorus | old, lower leaves | Slow, stunted growth with a purplish tint on older leaves, most on the underside. | Superphosphate 0 20 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 | New leaflets come out small, pale between the veins and crowded on short shoots. | Zinc sulfate |
Before you buy fertilizer for a santol nutrient deficiency
So use the table to pick the likeliest santol 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 santol
The signs on santol are like those on other fruit trees. The whole tree turns light green, and the older leaves turn yellow, then brown, and fall. New shoots are short and thin, growth is slow, and the tree flowers and fruits less. You see it most at this stage: young trees in the first years after planting, and bearing trees after a heavy crop.
Why nitrogen deficiency happens in santol
Trees that get no fertilizer or manure, sandy or eroded soils low in humus, and heavy rain that washes nitrogen down. Grass and weeds close to the trunk compete for it.
How to tell it apart
Santol leaves normally turn red or yellow just before they fall. The tree is partly deciduous and at times sheds most of its leaves at once. To be sure, A leaf test of mature leaves from recent growth shows low nitrogen. New leaves that come out greener and bigger after a nitrogen dose confirm it.
What to apply for nitrogen deficiency
In the first year, give 100 to 200 grams of Ammonium sulfate 21 0 0 per tree a month after planting. Give it again before the rains end. Young bearing trees get 200 to 500 grams of a complete fertilizer twice a year. Full grown trees need at least 2 kg of complete fertilizer per application. Use Complete 14 14 14, spread in a ring under the canopy edge and watered in or put on moist soil.
- Ammonium sulfate 21 0 0
- Complete 14 14 14
- Urea 46 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, keep a weed free circle about 50 cm around young trees, mulch, add manure. Feed every year at the start and near the end of the rainy season. Let a soil test and the crop's color set the season's nitrogen.
Potassium deficiency in santol
The signs on santol are like those on other fruit trees. The edges and tips of older leaflets look burnt, and the scorch moves inward. Fruit size and quality drop, and the tree may suffer more from disease. You see it most at this stage: bearing trees, most of all during fruit growth.
Why potassium deficiency happens in santol
Sandy, leached soils under heavy rain, and years of fruiting with no potash returned.
How to tell it apart
Pink disease (Corticium salmonicolor), common on santol, forms cankers on branches. Fungal blights make the leaves on whole twigs and branches wilt and die. To be sure, A soil test for potash and a leaf test.
What to apply for potassium deficiency
Feed bearing trees Complete 14 14 14. Young bearing trees take 200 to 500 grams twice a year, full grown trees 2 kg or more each time. Where the soil test shows low potash, add Muriate of potash 0 0 60 in split doses under the canopy, following the soil test. Give 200 to 500 grams of Muriate of potash 0 0 60 a bearing tree a year in two doses, more while fruits are filling.
- Complete 14 14 14
- Muriate of potash 0 0 60
- Sulfate of potash 0 0 50
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 a complete fertilizer every year from the first crop on, and return fallen leaves and prunings under the tree. Keep organic matter up with compost, manure or crop residues.
Phosphorus deficiency in santol
The signs on santol are like those on other fruit trees. Growth is slow and the tree stays small for its age. Older leaves take on a purple color, most of all on the underside. You see it most at this stage: young trees after planting, and trees on poor acid soils.
Why phosphorus deficiency happens in santol
Acid and eroded soils low in humus, and trees that get no phosphate at planting or later.
How to tell it apart
Santol leaves turn red before they fall as a normal habit. So look for the purplish tint on leaves that are still firmly attached and on a tree that is also growing slowly. To be sure, A soil test for available phosphorus and pH, and a leaf test.
What to apply for phosphorus deficiency
Work Superphosphate 0 20 0, 16 20 0 or Ammonium phosphate 18 46 0 into the soil under the canopy, following the soil test, with manure or compost. For bearing trees, Complete 14 14 14 also supplies phosphate. 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.
- Superphosphate 0 20 0
- 16 20 0
- Ammonium phosphate 18 46 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, put phosphate and manure in the planting hole, and lime very acid soils according to the soil test. Santol grows best in loose, friable soils with plenty of humus.
Zinc deficiency in santol
The signs on santol are like those on other fruit trees. Zinc is the most widespread micronutrient shortage in fruit crops. Young leaves turn yellow between the veins and come out small, narrow and sometimes distorted. Shoots stay short so the leaves crowd in a rosette. Flowering and fruit size drop. You see it most at this stage: new flushes, when shoots grow fast.
Why zinc deficiency happens in santol
Sandy, leached soils, high pH or overlimed soils, and heavy phosphate fertilizer, which can hold back zinc uptake.
How to tell it apart
Gall mites (Eriophyes sandorici), the most serious santol pest, cause galls, bumps on the leaves, and stunted young trees. Zinc shortage gives small pale leaves without galls. To be sure, A leaf test for zinc and a soil test for pH and zinc. Spray a few branches and see whether the next flush comes out normal sized. In a soil test, less than 0.8 ppm of zinc is low.
What to apply for zinc deficiency
Santol has no zinc rate of its own, so borrow the one used on other fruit trees. Use a 0.5 percent Zinc sulfate spray (5 grams per liter, 80 grams in a 16 liter sprayer) on several fruit trees, for example guava before flowering. So try it on a few branches of the new flush first. On soils proven low in zinc, add Zinc sulfate to the soil following the soil test. 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 heavy phosphate alone, and add compost or manure every year.
A soil test is the surest check for any santol 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 santol needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick santol, 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
Santol nutrient deficiency questions
Why are my santol leaves turning yellow?
What fertilizer fixes nitrogen deficiency in santol?
What fertilizer fixes potassium deficiency in santol?
What fertilizer fixes phosphorus deficiency in santol?
How do I know which nutrient my santol 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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