Chili Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Chili nutrient deficiency is one of the first things to check when the leaves of your sili (chili) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, potassium, calcium, phosphorus, magnesium, boron, zinc, sulfur 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, phosphorus and magnesium move inside the plant, so a shortage shows on the old, lower leaves first. But calcium, boron, zinc, sulfur 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 chili nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Chili 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 | Lower leaves turn pale yellow, veins included, and plants branch little. | Urea 46 0 0, Ammonium sulfate 21 0 0 |
| Potassium | old, lower leaves, leaf edges and tips | Leaf tips and edges burn brown and leaves crinkle and curl. | Muriate of potash 0 0 60, Sulfate of potash 0 0 50 |
| Phosphorus | old, lower leaves, the roots | Purple stems and leaf undersides, few branches, and late flowering. | Ammonium phosphate 16 20 0, Complete 14 14 14 |
| Magnesium | old, lower leaves, between the veins | Leaves that just reached full size turn yellow between the big green veins and drop early. | Magnesium sulfate (Epsom salt), Dolomite |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Calcium | fruit, grain or tubers, young leaves and the tip | Sunken, water soaked spots at the tip of the fruit that dry out and turn black. | Agricultural lime, Dolomite |
| Boron | young leaves and the tip, fruit, grain or tubers | Brittle, twisted new leaves and fruits that crack or drop. | Borax, Solubor (sodium borate) |
| Zinc | young leaves and the tip, between the veins | Young leaves are small, stiff and mottled yellow, and the plant is short jointed. | Zinc sulfate |
| Sulfur | young leaves and the tip, the whole plant | Young top leaves turn evenly pale and curl down, with reddish veins. | Ammonium sulfate 21 0 0, Gypsum |
| Manganese | young leaves and the tip, between the veins | Young leaves are mottled yellow with a fine net of green veins and dark spots along the veins. | Manganese sulfate |
Before you buy fertilizer for a chili nutrient deficiency
So use the table to pick the likeliest chili 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 chili
Older leaves turn pale to light green and then yellow evenly, veins included. Plants branch less and stay short, leaves are small, and fruits are small and pale. In severe cases lower leaves yellow and drop early. You see it most at this stage: from early growth through fruiting.
Why nitrogen deficiency happens in sili
Sandy soils, heavy rain or watering, low organic matter and long gaps between side dressings.
How to tell it apart
Sulfur shortage starts on the young leaves. Magnesium shortage keeps veins green on old leaves. To be sure, check that the bottom leaves yellow first, then do a soil test and leaf tissue test.
What to apply for nitrogen deficiency
Side dress with urea or ammonium sulfate based on the soil test. For a quick fix, try a urea spray at 10 grams per liter of water (160 grams in a 16 liter sprayer) every 15 days. Side dress 5 to 10 grams of Urea 46 0 0 a plant, about 1 to 2 bags per hectare, every two to three weeks from flowering, and water it in.
- 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, Crown Champion Ammonium Sulfate by Aqua Hydroponic Prime Ventures (21 0 0 with 24 percent sulfur), Agripower 46 0 0 (Locally Blended) Coated by Green Acres Agri Tech and Amigo Planters Sabic Zinc Coated Urea by La Filipina (46 0 0 with 0.1 percent zinc). 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, add compost at planting and split nitrogen into several side dressings.
Potassium deficiency in chili
Leaf tips burn and dead patches appear between the veins, starting on older leaves. Leaves crinkle and curl, become fewer and smaller, and the plant is stunted. Yellowing from potassium shortage does not recover even after feeding, so act early. You see it most at this stage: fruiting, when fruits draw potassium from the leaves.
Why potassium deficiency happens in sili
Sandy or acid soils, heavy rain that leaches potassium, and fertilizer programs with little potash.
How to tell it apart
Salt or fertilizer burn also scorches tips. Check if fertilizer was placed too close to the stem. To be sure, soil test for potassium and a leaf tissue test.
What to apply for potassium deficiency
Apply muriate of potash based on the soil test, in split doses. For immediate relief, try a morning spray of sulfate of potash at 10 grams per liter of water (160 grams in a 16 liter sprayer) with a sticker. Lime acid soil to keep pH above 6. A usual dose is 1 to 2 bags of Muriate of potash 0 0 60 or Sulfate of potash 0 0 50 per hectare, split from flowering to fruit fill.
- Muriate of potash 0 0 60
- Sulfate of potash 0 0 50
- 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, give potash at planting and again at flowering and fruiting. Keep organic matter up with compost, manure or crop residues.
Calcium deficiency in chili
Sunken, water soaked spots form near the tip (blossom end) of the fruit, then harden, dry and turn black. Mould may grow on them. Young leaves curl upward, are small and deformed, and their edges yellow then die. Root and shoot tips can brown and die, and flower buds may fail. You see it most at this stage: flowering and early fruit growth, in hot dry spells.
Why calcium deficiency happens in sili
Uneven watering and dry spells, acid sandy soils, salty soils, and heavy nitrogen or potassium. Boron shortage and high phosphorus can add to it.
How to tell it apart
Sunscald makes pale papery patches on the sun side of the fruit, not at the tip. Fruit rots from disease spread fast and are soft from the start. To be sure, look for the spots at the tip end of young fruits after dry weather, then do a soil test for calcium and pH.
What to apply for calcium deficiency
Water evenly and mulch. On acid soil, lime by the soil test: usually 1 to 3 tons of Agricultural lime or Dolomite per hectare, mixed in 2 to 4 weeks before planting. Gypsum on soil that is not acid. Remove affected fruits.
- Agricultural lime
- Dolomite
- Gypsum
- Calcium nitrate
Sold here with calcium: Micronized Activated Calcite by CMCS Agricultural Products (37.6 percent calcium), Dolomite by A6 Agrisource (24 percent calcium and 11 percent magnesium), Titon Pro by Vast Agro (27.2 percent calcium, 6.1 percent silicon and 3.6 percent magnesium) and Crown Champion Nitrogen Calcium Compound (Cal Nit) by Aqua Hydroponic Prime Ventures (15 0 0 with 18 percent calcium). 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 soil before planting, keep the soil evenly moist, and avoid heavy ammonium fertilizer. Keep potash in balance with magnesium and calcium.
Phosphorus deficiency in chili
Stems, leaf stalks and the undersides of leaves turn purple. In severe cases leaves get a blue grey sheen. Plants have fewer leaves, short thin shoots, few branches and weak roots. Flowering and ripening come late and fruits are small and distorted. You see it most at this stage: seedling and early growth.
Why phosphorus deficiency happens in sili
Acid or iron rich soils, low organic matter, cold or waterlogged soils.
How to tell it apart
Cool nights can turn seedlings purple for a short time. Nitrogen shortage gives pale rather than purple leaves. To be sure, soil test for available phosphorus and pH.
What to apply for phosphorus deficiency
Apply the recommended phosphorus near the roots based on the soil test. Use single superphosphate for a quick fix and rock phosphate or bone meal for the long term. Keep soil near pH 6.2 to 7.0. A usual basal dose is 4 to 6 bags of Complete 14 14 14 per hectare, 10 to 20 grams a hill, mixed into the soil at transplanting.
- Ammonium phosphate 16 20 0
- Complete 14 14 14
- Single superphosphate
- 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, use a phosphorus starter at transplanting and add compost.
Magnesium deficiency in chili
Leaves that have just reached full size, and older leaves, turn yellow between the veins while the largest veins stay green. Dead spots form in the yellow areas, leaves drop early and yield falls. You see it most at this stage: fruiting.
Why magnesium deficiency happens in sili
Sandy acid soils, heavy rain, and heavy potash or ammonium fertilizer.
How to tell it apart
Manganese and iron shortage start on the young top leaves, where even small veins stay green. To be sure, soil test for magnesium and potassium, and a leaf tissue test.
What to apply for magnesium deficiency
Try magnesium sulfate in a band near the plants at about 80 kg per hectare. Do not apply magnesium and potassium fertilizer together. Put the soil dose in before planting or when the rains begin. Sprays show results in 10 to 14 days.
- 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, use dolomite on acid soil. Test the soil every two or three years. Lime acid soil with Dolomite rather than plain lime.
Boron deficiency in chili
New leaves are pale, misshapen, brittle and small, and the plant loses its main tip and grows bushy. Fruits stay small and light, crack, and drop before they mature. You see it most at this stage: flowering and fruit set.
Why boron deficiency happens in sili
Sandy soils where boron leaches, heavily limed or alkaline soils, low organic matter and drought.
How to tell it apart
Virus diseases also twist new leaves. Check for insects such as thrips and mites, and whether the pattern follows soil patches. To be sure, soil test for boron and a leaf tissue test. In a soil test, less than 0.5 ppm of boron is low.
What to apply for boron deficiency
Try borax in the soil at about 10 kg per hectare or a borax spray at 1 gram per liter of water (16 grams in a 16 liter sprayer). Peppers need only a little boron, so do not repeat doses without a test. Do not mix borax with calcium or ammonium fertilizer. Give boron before flowering: flowers and fruit set need it most.
- Borax
- Solubor (sodium borate)
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, use boron only where tests show low levels, and keep organic matter up. Test the soil every two or three years.
Zinc deficiency in chili
Young leaves yellow between the veins and can turn whitish. Leaves are small, stiff and brittle, stems are thin, and the space between leaves is short. The crop matures unevenly. You see it most at this stage: vegetative growth and early flowering.
Why zinc deficiency happens in sili
High pH or overlimed soil, heavy phosphorus fertilizer, waterlogged soil.
How to tell it apart
Leaf curl virus also makes small, crinkled leaves, but it comes with whiteflies on the plants. Zinc shortage shows yellowing between the veins over a whole soil patch. To be sure, soil test for zinc and pH, and a leaf tissue test. In a soil test, less than 0.8 ppm of zinc is low.
What to apply for zinc deficiency
Try zinc sulfate in the soil at about 20 kg per hectare. In severe cases a morning spray of zinc sulfate at 2 grams plus calcium carbonate at 2.5 grams per liter of water (40 grams in a 16 liter sprayer). Do not apply zinc and phosphate together. Give the soil dose at planting or when the rains begin, and sprays on young growth.
- 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), Semia by SCL Filipinas (20 percent zinc) and Omex Zynergy by Jardine Distribution (3.8 percent zinc and 2.1 percent copper). 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, keep soil pH between 5 and 7.5 and avoid excess phosphorus. Test the soil every two or three years.
Sulfur deficiency in chili
Young leaves turn pale then yellow overall, with reddish veins and leaf stalks. Leaves are small, brittle and twisted and curl downward, and growth is held back. You see it most at this stage: early growth on light soils.
Why sulfur deficiency happens in sili
Sandy, low organic matter soils and fertilizer programs with no sulfur.
How to tell it apart
Nitrogen shortage starts at the bottom leaves. To be sure, soil test for sulfate and a leaf tissue test. In a soil test, less than 10 ppm of sulfate sulfur is low.
What to apply for sulfur deficiency
Use ammonium sulfate or other sulfur containing fertilizer. Try sulfur dust at about 25 kg per hectare on sulfur deficient soil, and gypsum on alkaline soil. Give it at planting or with the first side dress.
- Ammonium sulfate 21 0 0
- Gypsum
- Elemental sulfur
Sold here with sulfur: Crown Champion Ammonium Sulfate by Aqua Hydroponic Prime Ventures (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 ammonium sulfate in the program and add organic matter. Do not burn crop residues. Test the soil every two or three years.
Manganese deficiency in chili
Leaves that are nearly full size show mottled yellowing between the veins. So a thin net of green veins stands out on the pale green blade. Young leaves yellow at the edges and dark dead areas form along the veins. Fruits may show raised dark brown to black spots. You see it most at this stage: vegetative growth and fruiting.
Why manganese deficiency happens in sili
High pH or overlimed soils, sandy soils, and cold wet spells.
How to tell it apart
Magnesium shortage starts on old leaves. Iron shortage gives a clean yellow without dark spots. To be sure, soil pH test and a leaf tissue test. In a soil test, less than 1 ppm of manganese is low.
What to apply for manganese deficiency
Try a manganese sulfate spray at 2 grams per liter of water (32 grams in a 16 liter sprayer) after a soil test confirms the need. 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), Turan by SCL Filipinas (11 percent manganese, 6 percent zinc and 2.8 percent copper), Tierramino MN by Unilox Far East Resources (7 0 0 with 12 percent manganese) and Multimate by Agway (4 0 0 with 4.5 percent sulfur, 2.8 percent zinc and 1.8 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, do not overlime. Keep soil pH near 6 to 6.5.
A soil test is the surest check for any chili 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 sili needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick sili, 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
Chili nutrient deficiency questions
Why are my sili leaves turning yellow?
What fertilizer fixes nitrogen deficiency in chili?
What fertilizer fixes potassium deficiency in chili?
What fertilizer fixes calcium deficiency in chili?
How do I know which nutrient my sili 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.
The account is free, no credit card.
