What Is Blight In Potatoes? 7 Uncomplicated Tips For Dealing With Blight In Potatoes


Blight is a fungal disease which is caused by the spores of phytophthora infestans. These spores moves with the help of wind and infect the plant. You do not even have an indication of blight until the plant gets spoiled.

Blight is particularly observed in warm and humid climatic conditions It mainly effects the outdoor plants.

Signs Of Blight In Potatoes

  • The main symptom of blight is brown rotten leafs which are wrinkled and dried. Not every dried leaf is a symptom of blight. But check for white fungal outline on the leaf blotch.

There is no way to cure the blight. All you can do is to reduce its intensity.

  • It starts with dark brown patches on the leaves later infects the stem and then plant.
  • Transported spores settle down under the leaves and starts turning the leaves into yellow color.
  • In next phase it makes that yellow leaf rotten, eventually spread and destroys the whole plant.
  • Wind transports spores from one plant to other plant. So, it is necessary to have a space between plants.
  • They can penetrate into the soil, reaches the tubers and infect them.
  • These spores causes reddish brown spots under the surface of the skin and spreads towards the center of potato.
  • Spores can endure in the soil or in compost heap.
  • Blight infected parts of the plant must be removed and destroyed. Else the spores remains in the ground.

So its better to practice crop rotation because it reduces the risk of infection.

How To Control Potato Blight


Chemical sprays must be used for blight infected plants. It will not kill the spores, but delay the death of plant.

Certified Seed Potato

Its better to start with certified seed potatoes because they are blight free.

The Blight Resistant Potato Varieties Are

  • Sarpo Mira
  • Kifli
  • Blue Danube
  • Orla
  • Shone
  • Sarpo Axona

Spacing Of Potato

Spacing must be provided between plants as it provides less blight friendly environment.


Make sure that you water at base of the plants but not on leaves. It boosts the transmission of spores which are present on the leaves.

Watering must be done in morning sessions. Because spilled out water on the leaves dries up due to temperature of the sun.


If you see any sign of blight, remove and destroy it by burning properly.

Don’t use blight infected leaves in composting because the spores are alive and spread through out the compost.

Avoid Companion Planting With Tomatoes

Avoid the planting of tomato plants beside the potato plants. Because tomatoes are easily prone to blight.


Don’t plant potatoes in shade because it boosts the spore growth.

Diseases That Show Symptoms Similar To Blight

  • Sun damage
  • Bortrytis
  • Wind burn
  • Magnesium deficiency
  • Blossom-end rot
  • Frost damage

Magnesium Deficiency

Magnesium deficiency confuses us with blight. If you observe any symptoms check the rotten part of the plant for white spores.

If you didn’t find any thing then give your plant a weak solution of epsom salt and water.


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