Spring onion Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Spring onion nutrient deficiency is one of the first things to check when the leaves of your sibuyas na mura (spring onion) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, potassium, sulfur, 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 sulfur and 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 spring onion nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Spring onion 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 | Thin, pale tops whose older leaves yellow from the tips. Stalks stay short. | Urea 46 0 0, Ammonium sulfate 21 0 0 |
| Potassium | old, lower leaves, leaf edges and tips | Dark green leaves whose older tips wilt, droop and turn papery. | Muriate of potash 0 0 60, Sulfate of potash 0 0 50 |
| Phosphorus | old, lower leaves, the roots | Slow, dull green plants whose leaf tips die back without yellowing. | 16 20 0, Single superphosphate 0 20 0 |
| Magnesium | old, lower leaves | Older leaves turn evenly yellow along their length, with white tips. | Epsom salt / magnesium sulfate, Dolomite |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Sulfur | young leaves and the tip, the whole plant | Young leaves are evenly pale yellow and the plants thin and weak. | Ammonium sulfate 21 0 0, Gypsum |
| Zinc | the whole plant, young leaves and the tip | Stunted plants with twisted leaves and faint yellow stripes. | Zinc sulfate |
Before you buy fertilizer for a spring onion nutrient deficiency
So use the table to pick the likeliest spring onion 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 spring onion
The leaves fade to pale green and then yellow, beginning at the tips of the oldest ones. The plants stay short and thin. For a crop sold as green leaves, this costs the harvest directly. You see it most at this stage: whole crop. The harvest comes in about 60 to 70 days.
Why nitrogen deficiency happens in sibuyas na mura
Sandy soils, heavy rain or watering that washes nitrogen out, and close planting with little fertilizer.
How to tell it apart
Sulfur deficiency yellows the young leaves first. Overwatering and root rot also yellow tips. To be sure, check that older leaf tips yellowed first. Soil test.
What to apply for nitrogen deficiency
Spread about 55 to 80 kg N per hectare before planting. Then sidedress about 85 to 110 kg more as needed to keep the tops green. For quick help give a 1 percent urea spray (10 g per liter, 160 g in a 16 liter sprayer) twice, a week apart, for onion.
- 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 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 in small doses through the crop and add compost. Let a soil test and the crop's color set the season's nitrogen.
Potassium deficiency in spring onion
Leaves turn darker green first, then older leaf tips wilt, droop and dry papery. Tip burn spoils the look of the bunches. You see it most at this stage: second half of the crop.
Why potassium deficiency happens in sibuyas na mura
Sandy soils and beds cropped many times without potash.
How to tell it apart
Nitrogen deficiency starts pale, not dark. To be sure, soil test for potassium.
What to apply for potassium deficiency
Broadcast about 170 to 190 kg K2O per hectare before planting, following the soil test. Give a 1 percent potassium sulfate spray (10 g per liter, 160 g in a 16 liter sprayer) twice, a week apart, for onion.
- 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, include potash in the basal fertilizer each crop. Keep organic matter up with compost, manure or crop residues. Split the potash on sandy soil.
Sulfur deficiency in spring onion
Young leaves turn evenly yellow first, then the whole plant. Plants stay thin and weak and taste mild. You see it most at this stage: early growth.
Why sulfur deficiency happens in sibuyas na mura
Sandy soils low in organic matter and years of sulfur free fertilizer.
How to tell it apart
Nitrogen deficiency starts at the tips of older leaves. To be sure, soil and leaf test for sulfur. 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 for part of the nitrogen, or add Gypsum or single superphosphate, following the soil test. Give about 25 kg sulfur dust per hectare on sulfur poor soil for onion. Give it at planting or with the first side dress.
- Ammonium sulfate 21 0 0
- Gypsum
- Single superphosphate 0 20 0
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, keep a sulfur source in the program. Keep organic matter up with compost, manure or crop residues.
Phosphorus deficiency in spring onion
Growth is slow and leaves turn a dull green. Leaf tips die back without the yellowing of nitrogen shortage, and roots are weak. You see it most at this stage: seedling to mid growth.
Why phosphorus deficiency happens in sibuyas na mura
Acid soils, cold soils and low soil phosphorus. Soils below pH 6 bring it on, so avoid them for spring onion.
How to tell it apart
Potassium deficiency also gives dark leaves but with wilting, papery tips. To be sure, soil test for phosphorus.
What to apply for phosphorus deficiency
Broadcast about 160 to 175 kg P2O5 per hectare before planting, following the soil test.
- 16 20 0
- Single superphosphate 0 20 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, lime acid beds to about pH 6.5 and apply phosphorus at planting.
Zinc deficiency in spring onion
Plants stay stunted, leaves twist and bend with faint yellow streaks. Onions are very sensitive to zinc shortage. You see it most at this stage: early growth.
Why zinc deficiency happens in sibuyas na mura
Soils above pH 6.5, over limed beds and heavy phosphorus.
How to tell it apart
Herbicide injury also twists leaves. To be sure, soil or leaf test for zinc. In a soil test, less than 0.8 ppm of zinc is low.
What to apply for zinc deficiency
Give a 0.5 percent zinc sulfate spray (5 g per liter, 80 g in a 16 liter sprayer) twice, 15 days apart, for onion. Add zinc sulfate to the soil only after a test confirms the need. 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), 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, test for zinc on high pH beds. Test the soil every two or three years. Do not overdo phosphorus.
Magnesium deficiency in spring onion
Older leaves turn evenly yellow along their whole length and the tips may whiten. Growth slows while the young leaves stay green. You see it most at this stage: mid growth.
Why magnesium deficiency happens in sibuyas na mura
Acid sandy soils and heavy potash.
How to tell it apart
Nitrogen deficiency starts at the leaf tips. To be sure, soil test for magnesium.
What to apply for magnesium deficiency
Give a 0.5 percent magnesium sulfate spray (5 g Epsom salt per liter) twice, a week apart, for onion. Use Dolomite on acid soils as the soil test advises. A usual dose is 100 to 150 kg of Kieserite or 150 to 200 kg of Magnesium sulfate per hectare at planting. On acid soil, 1 to 2 tons of Dolomite mixed in before planting both limes and feeds.
- Epsom salt / magnesium sulfate
- 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, lime acid beds with dolomite. Keep potash in balance with magnesium and calcium.
A soil test is the surest check for any spring onion 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 sibuyas na mura needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick sibuyas na mura, 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
Spring onion nutrient deficiency questions
Why are my sibuyas na mura leaves turning yellow?
What fertilizer fixes nitrogen deficiency in spring onion?
What fertilizer fixes potassium deficiency in spring onion?
What fertilizer fixes sulfur deficiency in spring onion?
How do I know which nutrient my sibuyas na mura 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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