Shallot Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Shallot nutrient deficiency is one of the first things to check when the leaves of your sibuyas tagalog (shallot) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, sulfur, potassium, phosphorus, zinc, boron 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, zinc and boron 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 shallot nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Shallot 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, upright leaves dying back from the tips, few side bulbs and small clusters. | Urea 46 0 0, Ammonium sulfate 21 0 0 |
| Potassium | old, lower leaves, leaf edges and tips | Leaves turn darker, older tips wilt and burn, and bulbs stay small. | Muriate of potash 0 0 60, Sulfate of potash 0 0 50 |
| Phosphorus | old, lower leaves | Slow, dull green plants with tips dying back and bulbs failing to fill. | 16 20 0, Single superphosphate 0 20 0 |
| Magnesium | old, lower leaves | Older leaves turn evenly yellow 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 turn evenly yellow, plants are thin, and bulbs are light and mild. | Ammonium sulfate 21 0 0, Single superphosphate 0 20 0 |
| Zinc | the whole plant, young leaves and the tip | Stunted plants with twisted, bent leaves and yellow stripes. | Zinc sulfate |
| Boron | young leaves and the tip, fruit, grain or tubers | Brittle, distorted leaves with cracks near the base, and split bulbs. | Borax |
Before you buy fertilizer for a shallot nutrient deficiency
So use the table to pick the likeliest shallot 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 shallot
Leaves turn pale green to yellow and die back from the tips, starting on the older leaves, and plants stay short. Clusters have fewer and smaller bulbs that mature early. Shallot (sibuyas Tagalog) is a form of onion, so onion signs and rates apply. You see it most at this stage: from planting to the start of bulbing.
Why nitrogen deficiency happens in sibuyas tagalog
Sandy soils, heavy rain or watering, and too little fertilizer.
How to tell it apart
Sulfur deficiency yellows young leaves first. To be sure, check that the oldest leaves yellowed first. Soil test.
What to apply for nitrogen deficiency
Split nitrogen from planting through early bulbing, following the soil test (onion nitrogen is often split every 10 to 14 days). For quick help give a 1 percent urea spray (10 g per liter, 160 g in a 16 liter sprayer) twice, a week apart. Side dress 1 to 2 bags of Ammonium sulfate 21 0 0 or 1 bag of Urea 46 0 0 per hectare at 3 and 5 weeks after transplanting.
- 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, stop nitrogen before bulbs mature, or they turn soft and store poorly. Keep organic matter up with compost, manure or crop residues.
Sulfur deficiency in shallot
Young leaves turn evenly yellow and the whole plant follows, staying thin and spindly. Bulbing is late and bulbs are lighter and less pungent. You see it most at this stage: before and during bulbing.
Why sulfur deficiency happens in sibuyas tagalog
Sulfur poor sandy soils and sulfur free fertilizers.
How to tell it apart
Nitrogen deficiency starts on older leaves. To be sure, run a soil test for sulfur. Poor soils can hold as little as 7 mg per kg.
What to apply for sulfur deficiency
On sulfur poor soil, 40 kg of sulfur per hectare as Ammonium sulfate 21 0 0 or single superphosphate with the usual NPK raised aggregatum onion yield by about a quarter. Ammonium sulfate also gave the most pungent, best quality bulbs. Give it at planting or with the first side dress.
- Ammonium sulfate 21 0 0
- Single superphosphate 0 20 0
- Gypsum
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, use ammonium sulfate or another sulfur source every crop. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Potassium deficiency in shallot
Leaves first turn darker green, then older leaf tips wilt, burn and turn papery. Bolting increases and bulbs stay small. Shallot (sibuyas Tagalog) is a form of onion, so onion signs and rates apply. You see it most at this stage: bulb development.
Why potassium deficiency happens in sibuyas tagalog
Sandy soils and fields cropped without potash.
How to tell it apart
Nitrogen deficiency starts pale. To be sure, soil test for potassium.
What to apply for potassium deficiency
Split potash, about a third to a half before planting and the rest during bulbing, 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. A usual dose is 1 to 2 bags of Muriate of potash 0 0 60 per hectare, half before transplanting and half when bulbs start to form.
- 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, keep potash in every crop on sandy soils. Keep organic matter up with compost, manure or crop residues.
Phosphorus deficiency in shallot
Growth and maturity are slow, and leaves turn dull green. Tips die back without yellowing, and bulbs fail to fill. You see it most at this stage: early growth.
Why phosphorus deficiency happens in sibuyas tagalog
Acid soils, cold soils and low soil phosphorus.
How to tell it apart
Potassium deficiency gives darker leaves that wilt and turn papery. To be sure, soil test for phosphorus.
What to apply for phosphorus deficiency
Apply 16 20 0 or single superphosphate at planting following the soil test. For a standing crop give a 2 percent DAP 18 46 0 spray (20 g per liter, 320 g in a 16 liter sprayer) twice, 15 days apart. A usual basal dose is 4 to 6 bags of Complete 14 14 14 or 2 to 3 bags of Diammonium phosphate 18 46 0 per hectare before transplanting.
- 16 20 0
- Single superphosphate 0 20 0
- Diammonium phosphate 18 46 0
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, apply phosphorus at planting.
Zinc deficiency in shallot
Plants stay stunted, leaves twist and bend and show yellow streaks. Onions, shallot included, are very sensitive to zinc shortage. You see it most at this stage: early growth.
Why zinc deficiency happens in sibuyas tagalog
Soils above pH 6.5 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. Give 6 kg of zinc per hectare in the basal fertilizer only when a soil test confirms the need.
- 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 before adding zinc. Do not overdo phosphorus.
Boron deficiency in shallot
Leaves are distorted, brittle and grey to blue green, with yellow cross lines that crack near the base. Bulbs can crack or split. You see it most at this stage: leaf growth to bulbing.
Why boron deficiency happens in sibuyas tagalog
Sandy soils low in organic matter and dry spells.
How to tell it apart
Calcium deficiency also kills tips but without cross cracks. To be sure, soil test for boron. In a soil test, less than 0.5 ppm of boron is low.
What to apply for boron deficiency
Give 1 kg of boron per hectare (about 9 kg Borax) before planting only when the soil test is low. Give about 10 kg Borax per hectare to the soil, or a borax spray of 1 g per liter (16 g in a 16 liter sprayer).
- Borax
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, never exceed the advised boron rate. Keep organic matter up with compost, manure or crop residues.
Magnesium deficiency in shallot
Older leaves turn evenly yellow along their length, with white tips and oval pale patches. Growth slows. You see it most at this stage: mid season.
Why magnesium deficiency happens in sibuyas tagalog
Acid sandy soils and heavy potash.
How to tell it apart
Nitrogen deficiency yellows from the tips with stiff upright leaves. To be sure, soil test for magnesium.
What to apply for magnesium deficiency
When the soil is low, give 30 kg of magnesium per hectare before planting. Give a 0.5 percent magnesium sulfate spray (5 g Epsom salt per liter) twice, a week apart.
- 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, use dolomite on acid soils. Test the soil every two or three years. Lime acid soil with Dolomite rather than plain lime.
A soil test is the surest check for any shallot 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 tagalog needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick sibuyas tagalog, 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
Shallot nutrient deficiency questions
Why are my sibuyas tagalog leaves turning yellow?
What fertilizer fixes nitrogen deficiency in shallot?
What fertilizer fixes sulfur deficiency in shallot?
What fertilizer fixes potassium deficiency in shallot?
How do I know which nutrient my sibuyas tagalog 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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