Tobacco Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Tobacco nutrient deficiency is one of the first things to check when the leaves of your tabako (tobacco) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, potassium, magnesium, sulfur, boron, calcium 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 and magnesium move inside the plant, so a shortage shows on the old, lower leaves first. But sulfur, boron, calcium 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 tobacco nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Tobacco 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 paler than the top leaves and dry up early. The plant stays small and the cured leaf is pale and thin. | Ammonium sulfate 21 0 0, Urea 46 0 0 |
| Potassium | leaf edges and tips, old, lower leaves | The tips and edges of the middle leaves turn yellow, then brown to black, and the cured leaf burns poorly. | Sulfate of potash 0 0 50, Ammonium sulfate 21 0 0 |
| Magnesium | old, lower leaves, between the veins | Lower leaves yellow between the veins, starting near the tip and edge, while the top stays green. | Dolomite, Magnesium sulfate (Epsom salt) |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Sulfur | young leaves and the tip, the whole plant | The bud and the top leaves pale first, and the whole plant slowly turns light green from the top down. | Ammonium sulfate 21 0 0, Sulfate of potash 0 0 50 |
| Boron | young leaves and the tip | The bud twists and dies, the top leaves are thick, brittle and curled down, and the midribs crack across. | Borax, Solubor |
| Calcium | young leaves and the tip, leaf edges and tips | New leaves bend down like a shepherd's crook, their edges yellow and die, and the bud can rot. | Agricultural lime, Dolomite |
| Manganese | young leaves and the tip, between the veins | Yellow netting between the veins with small white spots, on fields that were limed too much. | Manganese sulfate |
Before you buy fertilizer for a tobacco nutrient deficiency
So use the table to pick the likeliest tobacco 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 tobacco
The lower leaves turn paler than the upper ones and then yellow and dry up early, which growers call burning up. The yellowing moves up the stalk as nitrogen moves from old leaves to the new growth. Plants stay short with small, thin leaves, and the cured leaf comes out pale and slick, so both yield and grade drop. You see it most at this stage: from two to five weeks after transplanting, when the crop grows fastest, up to topping.
Why nitrogen deficiency happens in tabako
Nitrogen washes out of sandy soils quickly after heavy rain or heavy irrigation. Skipping or delaying the sidedress after off barring brings it on.
How to tell it apart
Sulfur shortage looks much alike, but it begins at the bud, the top leaves go pale first. The bottom leaves are spared the scorching that nitrogen shortage brings. To be sure, A soil test does not tell how much nitrogen tobacco needs, because nitrogen leaches. Compare what the field got with the nitrogen rate and timing set for your tobacco type. Send a leaf sample to a lab if you are unsure whether it is nitrogen or sulfur.
What to apply for nitrogen deficiency
Sidedress with Ammonium sulfate 21 0 0 along the row as soon as you see it, then hill up. For Virginia neutral flavor tobacco, give 4 bags of 10 18 24 at transplanting. Then give 4 bags of Ammonium sulfate 21 0 0 at 21 to 28 days after transplanting. Native tobacco programs use Urea 46 0 0 as the sidedress. Do not overdo it. Too much nitrogen slows ripening, makes curing harder and brings more suckers, hornworms and aphids. A usual dose is 60 to 90 kg of nitrogen per hectare, split at transplanting and 3 to 4 weeks later.
- Ammonium sulfate 21 0 0
- Urea 46 0 0
- Complete 14 14 14
Sold here with nitrogen: Atlas Granular Urea (46 0 0) by Atlas Fertilizer, Agripower 46 0 0 (Locally Blended) Coated by Green Acres Agri Tech, Calcipro by Ramgo (15.5 0 0 with 18.8 percent calcium) 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, give the full nitrogen rate for your tobacco type, split between transplanting and the sidedress. On fairly to very fertile soils, use only 75 percent of the rate. Let a soil test and the crop's color set the season's nitrogen.
Potassium deficiency in tobacco
Leaf tips and edges yellow first on leaves in the middle of the stalk. If not corrected, the yellowing spreads to the upper leaves, and in bad cases the yellow tissue turns black and falls away. Leaf yield, quality and price all drop, and leaf low in potash burns poorly. You see it most at this stage: mid season to ripening, often during weather extremes: drought, long wet spells or very hot weather.
Why potassium deficiency happens in tabako
Potash leaches from deep sandy soils, and dry soil or waterlogged soil slows its movement to the roots. Often the weather and weak roots cause it, not just too little potash in the soil. The dried leaf needs 3 to 6 percent potassium, so the shortage shows once it falls below 3 percent.
How to tell it apart
Magnesium shortage also yellows lower leaves, but the yellow runs between the veins, starting near the edge and tip, rather than a scorch on the edge itself. Natural ripening yellows the whole leaf evenly from the bottom up. To be sure, send a leaf sample and a soil test for potash to a lab. Check the soil moisture and the roots. Many cases clear by themselves once the soil is moist and the roots grow again.
What to apply for potassium deficiency
Use Sulfate of potash 0 0 50, not Muriate of potash 0 0 60. Skip muriate, because it is about 40 percent chlorine. Chlorine above about 34 kg per hectare is toxic to the crop. Chloride in the leaf makes it burn poorly and spoils its color, aroma and keeping quality. For Virginia and Burley, give all the potash as 0 0 50 or the tobacco grade 10 18 24. For example, Virginia neutral flavor gets 1 bag of 0 0 50 sidedressed at 21 to 28 days after transplanting. Give extra potash only when rain has badly leached it from the soil.
- Sulfate of potash 0 0 50
- Ammonium sulfate 21 0 0
Sold here with potassium: Simplot Sulfate 0 0 50 by Nutranta, Potassium Nitrate by Parafield (13 0 46), Qrop Mix Production 14 0 23 plus 13 Cao by Farmtech Agriland (14 0 23 with 9.3 percent calcium) and Cambiar K by Donato C. Cruz (0 0 48). 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 the full potash rate for your tobacco type as sulfate of potash. Split it on sandy soils so rain does not wash it away. Keep the soil evenly moist.
Magnesium deficiency in tobacco
The lower, older leaves yellow between the veins first, starting at the leaf edge near the tip, while the veins stay green. Dead brown patches can form between the veins later. Magnesium moves from old leaves to the new growth, so the top stays green the longest. You see it most at this stage: mid to late season. Worst after heavy rain on sandy soil.
Why magnesium deficiency happens in tabako
Deep sandy soils under heavy leaching, acid soils that were not limed, and heavy potash use. It can show even on limed fields when sandy soil is heavily leached.
How to tell it apart
Potash shortage starts as a yellow scorch on the tip and edge of middle leaves. Manganese shortage also yellows between the veins, but on the upper leaves. To be sure, do a soil test with pH, magnesium and potash, and a leaf test.
What to apply for magnesium deficiency
Keep the soil pH at 5.8 to 6.2 with Dolomite, which gives both calcium and magnesium. Where soils are sandy and leached, they advise 17 to 22 kg of magnesium per hectare in the fertilizer. Sulfate of potash magnesia (K Mag, 0 0 22 with 11 percent magnesium) gives magnesium with the potash. Magnesium sulfate (Epsom salt) also works. Follow the label for a leaf spray. Put the soil dose in before planting or when the rains begin. Sprays show results in 10 to 14 days.
- 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, lime with Dolomite rather than plain lime, based on a soil test. A fertilizer with magnesium is no substitute for lime when the soil pH is too low.
Sulfur deficiency in tobacco
Yellowing starts in the bud and the youngest leaves, and the leaves slowly pale from the top down. Unlike nitrogen shortage, the lower leaves do not dry up early unless nitrogen is also short. Adding nitrogen does not green the plant and can lower leaf quality. You see it most at this stage: early to mid season, after heavy rain.
Why sulfur deficiency happens in tabako
It shows most after heavy rain on deep sandy soils with very little organic matter. When the fertilizer carries no sulfur. Urea gives no sulfur, while Ammonium sulfate 21 0 0 and Sulfate of potash 0 0 50 do.
How to tell it apart
Nitrogen shortage gives the same pale color, but it starts on the lower leaves, which dry up early. Often only a leaf test can tell the two apart. To be sure, send a leaf sample to a lab. Soil tests for sulfur are not very reliable, so a leaf test tells more. In a soil test, less than 10 ppm of sulfate sulfur is low.
What to apply for sulfur deficiency
Act as soon as you see it, before the last hilling up. Band 112 to 168 kg per hectare of Sulfate of potash 0 0 50 or sulfate of potash magnesia. Ammonium sulfate 21 0 0 as the sidedress also adds sulfur.
- Ammonium sulfate 21 0 0
- Sulfate of potash 0 0 50
- Kieserite
Sold here with sulfur: Atlas Ammosul 21 0 0 by Atlas Fertilizer (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, each year, give about 22 to 34 kg of sulfur per hectare through the fertilizer. Ammonium sulfate and Sulfate of potash, the usual tobacco fertilizers, both carry sulfur. Test the soil every two or three years.
Boron deficiency in tobacco
Plants are stunted early. The growing point twists, and the youngest leaves get kinks, then turn thick and brittle with a ridged feel. The bud soon dies and may drop off, and suckers grow because the top is lost. Whole leaves curl down and crinkle, older leaves turn darker green. In bad cases the midribs crack across near the stem and the stem shows brown spots. You see it most at this stage: early, from a few weeks after transplanting. Once signs start, they move fast.
Why boron deficiency happens in tabako
In general, boron runs short on sandy soils low in organic matter, on soils limed to a high pH, and in long dry spells.
How to tell it apart
Calcium shortage also kills the bud and twists new leaves. But calcium shortage curls only the leaf edges down, while boron shortage curls the whole leaf down. To be sure, send young leaves to a lab for a leaf test, and test the soil and its pH. In a soil test, less than 0.5 ppm of boron is low.
What to apply for boron deficiency
Apply Borax or Solubor to the soil or as a leaf spray, following the label or a soil test. Boron is easy to overdo. Too much boron poisons tobacco, so measure the dose with care. A usual soil dose is 5 to 10 kg of Borax per hectare (0.5 to 1 kg of boron), mixed evenly with the basal fertilizer. A spray of Borax or Solubor at 0.1 to 0.2 percent (16 to 32 grams in a 16 liter sprayer) before flowering also works. Use the soil dose or the spray, not both.
- Borax
- Solubor
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, keep organic matter up, do not lime above the pH your soil test calls for. Test the soil for boron before planting.
Calcium deficiency in tobacco
The edges of the newest leaves turn yellow, and those edge cells die. Because the dead edges cannot grow, the new leaf bends down at the tip like a shepherd's crook. The edges then tear and brown, and in bad cases the growing tip dies with a dark, spongy bud, the plant stops growing and suckers take over. You see it most at this stage: fast growth before topping, mostly during drought or waterlogging.
Why calcium deficiency happens in tabako
Acid soils low in calcium. It can show even with enough calcium in the soil, when drought or waterlogging stops the roots from taking it up. Heavy potash or ammonium fertilizer, salty soil and dry spells keep calcium from reaching fruit and young leaves.
How to tell it apart
Boron shortage also kills the bud, but it curls the whole leaf down and cracks the midribs. But calcium shortage curls the leaf edges down first. To be sure, do a soil test with pH and calcium, and a leaf test of young leaves.
What to apply for calcium deficiency
Correct acid soil with Agricultural lime or Dolomite, based on a soil test. Keep tobacco soil at pH 5.8 to 6.2. Where lime does not cover it, they give 45 to 56 kg of calcium per hectare through the fertilizer. Gypsum adds calcium without raising pH. Water evenly in dry spells. Lime 2 to 4 weeks before planting. Calcium sprays go on young fruit from fruit set.
- Agricultural lime
- Dolomite
- Gypsum
- Calcium nitrate
Sold here with calcium: Planters Products Lifelime (36.2 percent calcium), Dolomite by A6 Agrisource (24 percent calcium and 11 percent magnesium), Calcipro by Ramgo (15.5 0 0 with 18.8 percent calcium) and Philphos Gypsum (22.2 percent calcium and 17.4 percent sulfur). 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 before planting, based on a soil test, and avoid long dry spells or waterlogging. Keep potash in balance with magnesium and calcium.
Manganese deficiency in tobacco
The leaves yellow between the veins, giving a white netted look. Small white spots then form and grow larger. It shows on the upper leaves. But their fertility page notes the flecks can look much like weather fleck from ozone. You see it most at this stage: mid season, mostly on soils with high pH.
Why manganese deficiency happens in tabako
Too much lime brings it on. It shows on soils low in manganese at pH 6.2 or higher. It should be rare on acid soils.
How to tell it apart
Weather fleck from ozone gives small flecks too, but soil pH is normal. Magnesium shortage yellows between the veins on the lower leaves instead. To be sure, do a soil test with pH and manganese, and a leaf test. In a soil test, less than 1 ppm of manganese is low.
What to apply for manganese deficiency
Use Manganese sulfate as a leaf spray or banded in the soil. Give about 3.4 kg of actual manganese per hectare in a band, 11 kg broadcast, or 0.56 kg as a leaf spray. Do not broadcast it on soils above pH 6.1. Spray Manganese sulfate at 0.2 to 0.5 percent (32 to 80 grams in a 16 liter sprayer) two or three times, 10 to 14 days apart.
- Manganese sulfate
Sold here with manganese: Manganese Sulfate by Zetryl Chem (31 percent manganese), Tierramino MN by Unilox Far East Resources (7 0 0 with 12 percent manganese), Multimate by Agway (4 0 0 with 4.5 percent sulfur, 2.8 percent zinc and 1.8 percent manganese) and Nutri Tabble Meta Foliar by NS Northern Organic Fertilizer (12 percent zinc, 9 percent sulfur, 2 percent magnesium and 1.2 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 lime above the rate your soil test calls for. Keep soil pH at about 5.8 to 6.2.
A soil test is the surest check for any tobacco 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 tabako needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick tabako, 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
Tobacco nutrient deficiency questions
Why are my tabako leaves turning yellow?
What fertilizer fixes nitrogen deficiency in tobacco?
What fertilizer fixes potassium deficiency in tobacco?
What fertilizer fixes magnesium deficiency in tobacco?
How do I know which nutrient my tabako lacks?
- NC State Extension Tobacco Growers Information: Fertility, nutrients (Vann)
- NC State Extension: Potassium fertility for flue cured tobacco, nutrient demand, application rates and deficiency
- K+S Kali Academy: Tobacco, potassium, chloride and leaf quality
- NC State Tobacco Diagnostic Key: Magnesium deficiency
- NC State Tobacco Diagnostic Key: Boron deficiency
- NC State Extension, From the Field Agronomy Notes: Boron deficiency in tobacco
- U.S. Borax crop guide: Boron deficiency in drug, fumitory and masticatory crops (tobacco)
- NC State Extension, From the Field Agronomy Notes: Calcium deficiency in tobacco
- NC State Tobacco Diagnostic Key: Calcium deficiency
- NC State Tobacco Diagnostic Key: Manganese deficiency
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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