Cucumber Nutrient Deficiency: Signs, Causes and the Fertilizer That Fixes It
Cucumber nutrient deficiency is one of the first things to check when the leaves of your pipino (cucumber) turn yellow, purple or burnt at the edges. On Philippine farms the usual ones are nitrogen, potassium, magnesium, phosphorus, calcium, boron 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, magnesium and phosphorus move inside the plant, so a shortage shows on the old, lower leaves first. But calcium, boron 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 cucumber nutrient deficiency you have, and a soil test confirms it. Each one below has its signs, its causes and its fix.
Cucumber 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 | Old leaves bleach yellow, vines are thin, and fruits come pale and misshapen. | Urea 46 0 0, Ammonium sulfate 21 0 0 |
| Potassium | old, lower leaves, leaf edges and tips | Old leaf edges yellow and scorch to dry paper, and fruits stay thin at the stem end. | Muriate of potash 0 0 60, Sulfate of potash 0 0 50 |
| Magnesium | old, lower leaves, between the veins | Older leaves yellow between the big veins, leaving a narrow green band along each vein. | Magnesium sulfate (Epsom salt), Dolomite |
| Phosphorus | old, lower leaves, the roots | Stunted vines with small, dull grey green leaves and weak roots. | Ammonium phosphate 16 20 0, Complete 14 14 14 |
Shows first on the young leaves
| Nutrient | Where it starts | What you see | Fix with |
|---|---|---|---|
| Calcium | young leaves and the tip, fruit, grain or tubers | Youngest leaves scorch and cup downward, the tip dies, and fruits fail at the blossom end. | Agricultural lime, Dolomite |
| Boron | young leaves and the tip, fruit, grain or tubers | Young fruits drop, and older fruits show yellow streaks that turn corky near the blossom end. | Borax, Solubor (sodium borate) |
| Manganese | young leaves and the tip, between the veins | Middle and upper leaves turn pale yellow while the veins stay green. | Manganese sulfate |
Before you buy fertilizer for a cucumber nutrient deficiency
So use the table to pick the likeliest cucumber 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 cucumber
Older leaves bleach, then yellow and die, and the yellowing climbs the vine. Growth is slow and stems are thin. Fruits are pale, small, thick or misshapen, and yield falls. You see it most at this stage: rapid vine growth and fruit set.
Why nitrogen deficiency happens in pipino
Sandy soils, heavy rain or irrigation, low organic matter, and too long between side dressings during harvest.
How to tell it apart
Magnesium shortage yellows between the veins of old leaves and leaves the veins green. Downy mildew makes angular yellow spots limited by the veins, not an even yellowing. To be sure, soil test and leaf tissue test. For the leaf test, pick the youngest fully grown leaf with its stalk at early flowering.
What to apply for nitrogen deficiency
Side dress urea or ammonium sulfate based on the soil test, in split doses. For a quick fix, give a urea leaf spray at 10 grams per liter of water (160 grams in a 16 liter sprayer) every 15 days. Put part of the season's nitrogen in before planting. Give the rest in one or two side dressings before fruit forms, or through drip lines. 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
- Calcium nitrate
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 and split nitrogen through the season.
Potassium deficiency in cucumber
The edges of older leaves turn yellow and scorch. The browning works inward between the veins until the whole leaf is as dry and brittle as paper. Leaves curl, dead spots form along the midrib, stems weaken and plants wilt easily. Fewer female flowers form, and fruits can be brown or spotted and fail to fill out at the stem end. You see it most at this stage: fruiting and harvest.
Why potassium deficiency happens in pipino
Sandy or acid soils, heavy rain or irrigation, and long harvests without potash side dressing.
How to tell it apart
Magnesium shortage yellows between the veins with a green band along the veins. Potassium burns the edges first. 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. Keep soil 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
- Potassium nitrate 13 0 46
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 and in side dressings through harvest. Keep organic matter up with compost, manure or crop residues.
Magnesium deficiency in cucumber
Older leaves turn yellow between the major veins while a narrow green border stays along the veins. The yellowing moves up the vine, and in severe cases the yellow tissue turns tan, papery and falls out, leaving holes. Yields drop. You see it most at this stage: fruit enlargement, during fast growth.
Why magnesium deficiency happens in pipino
Sandy soils with low holding capacity, low pH, dry years, and heavy potash, lime or ammonium fertilizer that compete with magnesium.
How to tell it apart
Manganese toxicity on very acid soil also gives yellow or bronze spots on old leaves. A soil pH test tells them apart. To be sure, soil test for magnesium, potassium and pH, and a leaf tissue test.
What to apply for magnesium deficiency
Keep the pH near 6.5 and feed Epsom salt, which is magnesium sulfate, through the drip lines. It notes leaf sprays usually do not fix a serious shortage. Try magnesium sulfate in a band near the plants at about 80 kg per hectare. Do not apply it with potash. For quick help, spray Magnesium sulfate at 1 to 2 percent (160 to 320 grams in a 16 liter sprayer) two or three times, 10 to 14 days apart.
- Magnesium sulfate (Epsom salt)
- Dolomite
- Magnesium oxide
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 before planting and avoid heavy potassium, calcium or ammonium fertilizer. Test the soil every two or three years.
Phosphorus deficiency in cucumber
Plants are stunted with weak roots. Leaves are small, dark and grey green, and leaves and veins can turn purplish. The oldest leaf may turn bright yellow while the one above stays dark green, and brown scorched patches form between the veins. You see it most at this stage: seedling and early vine growth.
Why phosphorus deficiency happens in pipino
Acid or iron rich soils, low organic matter, cold or waterlogged soil, and no phosphorus at planting.
How to tell it apart
Root knot nematodes also stunt vines. Pull a plant and look for galls on the roots. To be sure, soil test for available phosphorus and pH.
What to apply for phosphorus deficiency
Apply 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. Uptake is best 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
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 such as 16 20 0 or 14 14 14 in the hill at planting.
Calcium deficiency in cucumber
The youngest leaves are scorched and distorted and cup downward, sometimes with yellow stripes along the midrib. Flowers may drop and the growing point can die. Fruits are small, tasteless and may fail to develop at the blossom end. You see it most at this stage: fast vine growth and early fruiting, in hot dry spells.
Why calcium deficiency happens in pipino
Uneven watering or dry soil, acid sandy soils, and heavy ammonium or potash. High phosphorus and low boron add to it.
How to tell it apart
Boron shortage also deforms new growth but brings corky streaks on fruit. To be sure, soil test for calcium and pH.
What to apply for calcium deficiency
Water evenly and mulch. On acid soil, try lime at about 250 kg per hectare when pH is 5.5 to 6, or about 840 kg per hectare in two doses when pH is 3.5 to 4.5. Gypsum on soil that is not acid. 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: 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 and keep the soil evenly moist. Test the soil every two or three years. Keep potash in balance with magnesium and calcium.
Boron deficiency in cucumber
New leaves are distorted and the oldest leaves get a broad yellow edge. Buds die so the plant grows bushy, and young fruits abort. Mature fruits show yellow streaks that turn corky (scurfing), often near the blossom end, and may crack or stay small. You see it most at this stage: flowering and fruit set.
Why boron deficiency happens in pipino
Sandy soils where boron leaches, overlimed soils, low organic matter and drought.
How to tell it apart
Poor pollination also causes young fruit to abort, but the leaves stay normal. 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). Cucumber has a medium boron need, about 2.2 kg of boron per hectare before planting. Do not mix borax with calcium or ammonium fertilizers.
- 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, add boron to the basal fertilizer on sandy soils, but never repeat doses without a test. Test the soil every two or three years. Keep organic matter up with compost, manure or crop residues.
Manganese deficiency in cucumber
On middle to upper leaves, the veins stay green while the rest of the blade turns pale green to yellow. Small dead spots and a fine net of green veins appear, and leaves are smaller with crimped edges. You see it most at this stage: vine growth and fruiting.
Why manganese deficiency happens in pipino
High pH or overlimed soil, sandy or organic soils, and cold wet spells.
How to tell it apart
Iron shortage hits the newest leaves with a sharper net pattern. Magnesium shortage starts on the oldest leaves. To be sure, soil pH and a leaf tissue test. Leaf tests for manganese mislead if fungicides containing manganese were sprayed. 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. 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.
A soil test is the surest check for any cucumber 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 pipino needs. That saves money, because extra fertilizer is money lost.
Open the Nutrient Deficiency Finder, pick pipino, 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
Cucumber nutrient deficiency questions
Why are my pipino leaves turning yellow?
What fertilizer fixes nitrogen deficiency in cucumber?
What fertilizer fixes potassium deficiency in cucumber?
What fertilizer fixes magnesium deficiency in cucumber?
How do I know which nutrient my pipino 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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