Gray Wall of Tomato Plant: Symptoms, Prevention & Management

Our experienced writers spend hours deep researching, considering both scientific and experimental info to bring the insights you can trust.  

Quick Answer: Gray Wall of Tomato Plant

Gray Wall disease of the tomato plant occurs on unripe fruits. The presence of dark brown to black necrosis in the outer fruit wall indicates gray wall disease. The tomato affected with this disease shows a grey color and stunted growth. High humidity and rise-fall in temperatures favor the development of the disease. A balanced fertilizer helps in handling the disease.

This is the detailed reference guide on the Gray Wall disease in the tomato plants with symptoms, prevention tips, and management tactics.

Let us begin!

What is Tomato Gray Wall Disease?

Blotchy ripening or Gray wall on the tomato is a physiological condition developed due to environmental factors. This disease does not affect the stems or leaves of the tomato plant. The symptoms are only found in the unripe tomatoes.

The factors that may lead to the gray wall disease in tomatoes are- 

  • Excess nitrogen.
  • Low Boron
  • Deficiency of calcium & potassium.
  • Reduced light period.
  • Fluctuating duration of clouds and sunlight.
  • Insufficient levels of soluble salts in the soil 
  • Lower temperatures
  • Heavy soils

How Gray Wall Harm Tomato Plants?

The gray wall disease of the tomato is very complicated. It does not show any signs of infection on the leaves, stems, and roots of the plants. 

The tomatoes impacted with gray wall ripen prematurely and evenly with both red and yellow areas.

The fruit do not ripen properly and “veins” of the interior of fruit develop on the inside walls of the fruit.

The fruits affected are not suitable for commercial processing. They can be even unfit for eating. 

The difference that exists between Gray Wall or Blotchy Ripening or any other tomato disease is that its causative agent is unknown. It makes the identification, penetration, and dissemination, and prevention of the gray wall harder. 

The gray wall of the tomato plant is a physiological disorder that can be caused by up and down in nutrient element levels or fluctuating environmental conditions. 

This disorder is affected by the Tobacco Mosaic virus present in the soil and soil compaction. Short days and high humidity also influence the growth of the disease.

Hot weather, fog, clouds, and shade encourage premature ripening in tomatoes.

How to Confirm that Gray Wall is Troubling your Tomato Plants?

The symptoms that characterize tomato gray wall disease can appear internally and externally to the fruit.

Internally to the tomato fruit, dark necrotic areas are usually in the vascular tissue of the pericarp tissue. The inside pulp of the fruit show grayish, yellowish, brownish, or greenish patches.

Externally, tomato skin shows a grayish and sunken appearance. Tomatoes look splotchy, mottled, or unevenly ripened. The splotches might even collapse towards the inside of the fruit.

Figure: Gray Wall On Tomato Fruit – External & Internal

The tomato is ripened with both red and yellow areas. Ripe fruit has brown or green spots on the interior of the fruit walls.

The gray wall of the tomato disease has sturdy stems, green nourishing foliage and, healthy roots.

Ways to Control Gray Wall Disease on Tomato Plant

It is very important to control the symptoms before it gets too late and all your tomatoes are gone.

1. Use a Suitable Fertilizer

Fertilizers are probably the best way to control and prevent gray wall disease.

Fertilizers for gray wall disease should not have an excess of nitrogen in it. But, it should contain abundant potassium.

Nitrogen promotes leaf maturation. Excessive nitrogen will enhance the growth of the leaf resulting in the shadowing of fruits. This will cause uneven ripening of fruits.  

Foliar spray of potassium sulfate or potassium phosphate will increase the levels of potassium in the soil.

Do not spray or apply fertilizer in the afternoon as it can result in leaf burn. 

2. Go for Resistant Varieties

Studies suggest that tomato gray wall disease can be a result of the tomato mosaic virus. So, one should buy tomato varieties resistant to the tomato mosaic virus.

Though resistant seeds do not guarantee you the prevention of disease, but they decrease the risk to a great extent.

Constant care and basic precautionary steps are required for resistant seeds also.

Ways to Prevent Gray Wall Disease in Tomato Plant

Gray wall disease does not show any early signs and therefore, its prevention becomes even more important.

Here are some of the key tips –

  • Test the pH and organic nutrient material of soil every year.
  • Enrich your soil with organic materials. Provide lots of potassium to the soil.
  • During hot temperatures and rainy weather, clip extra leaves so that enough sunlight can reach the fruits of the tomato plant. Do not expose your fruits to so much sunlight that, they might lead to sunscald.

Ensure Proper Drainage

Provide your tomato plants with enough drainage. You can achieve this by two methods-


Construct narrow trenches alongside your tomato soil bed.

This will just wet the soil of the plant and will ensure proper drainage. It will not result in any wetness of foliage.

Gentle watering

Water your plants very gently on the roots. Do not perform overhead watering or sprinkle irrigation.

Monitor & Improve Soil

Improve your soil structure by- 

  1. Keep tabs on your soil structure.
  2. Avoid pruning or tilling of soil when it is wet.
  3. Do not plant seeds in wet soil.
  4. Do not harvest your tomatoes in wet soil.
  5. Do not perform the movement in your garden when the plants are wet.
  6. Enrich the soil with organic matter.
  7. Feed your plants with good sunlight, enough water, and nutrients.

Soil Compaction

Check the soil compaction of the tomato plant.

Soil compaction occurs when soil particles are so close that they reduce pore space between them. 

Do not use heavy garden tools, or perform tilling. These mistakes can result in soil compaction.


Mulch your plants with organic material or plastic polythene sheets to provide enough space between the soil and the plant.

It will supply organic matter to your soil.


How tomato gray wall is different from Tomato Mosaic Virus?

Tomatoes affected by gray wall show symptoms on unripe fruit only. 

Tomato mosaic virus develops mottling and spotting on both fruit and leaves.

Are tomatoes infected with gray wall disease safe to eat?

Yes, the tomatoes are edible. They show discolored sections on the inner side but those parts of the tomato could be trimmed away.

Can gray wall disease spread in open field?

Yes, the disease can develop in open area. The gray wall disease can also occur on the tomato plants that are under care.

Does gray wall affect green tomato fruits?

Yes, gray wall disease can start its early infection from young and green tomatoes. However, the symptoms will be developed on ripened tomatoes. 

Which season tomatoes are mostly affected by gray wall disease of the tomato plant?

It mainly affects early unheated crops or late autumn protected crops. But, it can affect any tomato plant during any season. 


I hope this guide helps you in protecting your tomato fruits from Gray wall disease.

Do share your experience of tackling Gray Wall in your tomato plants.

Share this guide with your family and friends who love planting tomatoes!