Brown Spots on Cauliflower: Cause, Symptoms and How to Prevent

Brown Spots on Cauliflower: Cause, Symptoms and How to Prevent

It is well known that cauliflower is a food that contains many healthy nutrients. However, this is also a crop that is susceptible to disease, namely disease of brown spots on cauliflower. Brown spot disease is very common and harmful to many crops such as cauliflower, rice, and dragon fruit. They are specially developed in hot, humid and rainy climates.

Among the diseases that cause crop failures and trouble farmers is brown spot disease on crops. So how does this disease manifest, how it must be prevented and treated? Let’s update the information in the article below to actively cultivate and take care of it effectively.

Brown Spots on Cauliflower

The Cause of Brown Spot Disease on Cauliflower Sentences

Brown spot is a disease caused by fungi. The scientific name of this fungus is Pseudomonas syringae. pv. Maculicola. The disease often has features such as round brown or oval dark spots initially on the leaves, stems or flowers of cauliflower. During the incubation period, it will cause stems, leaves or flowers to darken and rot, causing the cauliflower to stop growing or die. The disease will develop quickly if it experiences prolonged wet and rainy weather.

Brown spots on cauliflower is bad for health
Brown spots on cauliflower is bad for health

What are the Symptoms of Brown Spots on Cauliflower?

The disease occurs mainly on white cauliflower, but broccoli, cabbage and radish can also be affected. The early symptoms of the disease are small and watery spots. These spots then become dark brown or purple, surrounded by a yellow border.

The individual spots are 2mm- 3 mm (1/8 in) in size, the spots are usually not shaped when combined, creating a wrinkled, ragged appearance on the leaves. With severely affected cauliflowers, the leaves can become discolored and weakened. The Pseudomonas syringae. pv. Maculicola bacteria cause small, gray to brown spots on cauliflower, which can affect both the surface and underlying tissues. Spotting symptoms can also occur on the stalks and cauliflower flowers.

What are the Conditions for Developing Brown Spots on Cauliflower?

The nutrient-poor soil conditions such as alkaline soil, semi-mountainous sandy soils along the foothills further facilitate the development of brown spots on cauliflower. Meanwhile, areas with long-term dryness or inundation are also good areas for brown spots on cauliflower to grow. Plants grown in soil that do not have nutrients are less resistant to pests and diseases.

Low humidity and high temperature cause disease to spread quickly, spreading throughout the crop area. Brown spots on cauliflower can also be spread through slugs, insects, wind or water currents. In general, if fungal spores appear, they can grow rapidly under any conditions.

  • This bacterium can persist in soil and in plant residues on soil surfaces for at least one year.
  • They can live on weeds. Spotting spreads from one plant to another through rain, watering or working tools that are not clean.
  • Insects can also spread this disease. Bacterial leaf and flower spot disease is most severe during cool and wet weather.
You should not eat this cauliflower with brown spots
You should not eat this cauliflower with brown spots

How to Prevent Brown Spots on Cauliflower?

Prevention is better than cure is the criterion that we should implement before sowing. There are some specific farming methods to prevent brown spots on cauliflower such as:

  • Cleaning weeds to make the garden clear, avoiding the environment for pathogens to grow.
  • Planted land must be renovated and provided with adequate nutrients for plants to have favorable conditions for development.
  • Do not water cauliflower in the evening, as humidity will allow germs to spread.
  • Diseased cauliflower must be collected and destroyed with powdered lime, not thrown around in the garden.
  • Apply fertilizer at the right time and at the right amount.
  • Select high-quality varieties with good germination ability and high disease resistance.
  • Use seeds without Pseudomonas syringae pv. maculicola and sowing seeds on beds that have been cleared of grass as well as old residues from previous crops.
  • If disease occurred on the planting beds before, the soil needs to be disinfected before planting.
  • Rotation of crops in previous crops is different from families without the same bacterial pathogens for at least one year, and then cruciferous crops are grown.
This is a fresh and clean cauliflower
This is a fresh and clean cauliflower

Frequently asked questions

1. In what regions often brown spots on cauliflower disease occur?

The disease of brown spots on cauliflower is a common crop disease all over the world, especially in hot, humid and rainy countries.

2. Why does it appear as a brown spot on cauliflower?

There are 2 reasons why brown spots occur on cauliflower:

  • 1 is that this cauliflower has been infected as mentioned above.
  • 2 is the cauliflower that becomes moldy when not being well preserved.

3. Should I eat cauliflower with brown spots?

If you find the brown mold and mildew spots that cause the cauliflower to discolor, remove them. Absolutely not eat because it will be harmful to health. Eating them can lead you to be poisoned. Besides, you should also not eat broccoli coming with the tiny yellow flowers, because they are starting to decompose at that time. Not only cauliflower but any vegetables, you should also choose fresh foods to eat.

4. How long can the cauliflower be preserved to avoid mold?

Cauliflower contains many vitamins and nutrients, such as Vitamins A and C, fiber and protein. After buying a fresh cauliflower, you should only store it for 3 days because the longer it keeps, the less vitamins in the cauliflower will be. In addition, the long-term preservation or improper storage of cauliflower also causes the cauliflower to get mold.

Cauliflower should be preserved within 3 days from harvesting
Cauliflower should be preserved within 3 days from harvesting

5. How do I identify brown spots on cauliflower?

  • During storage, to see if the cauliflower has been damaged, you must examine it. Here are some steps to help you realize that cauliflower is no longer in use for processing:
  • Examine the tiny flowers on the cauliflower, if the flowers appear yellow, they are beginning to show signs of decomposition. Fresh cauliflower will be fresh green or white.
  • Look carefully at this cauliflower for signs of mold. Mold often appears on cauliflower discolored areas. If you notice mold, throw it away immediately. If it is still used, it will not be good for your health and for the whole family.
  • Touch the cauliflower to see if it is still firm. If they are soft, they can no longer be used for processing.
  • If the cauliflower smells strange or bad, remove it immediately. It certainly can’t be used anymore.


Cauliflower is a nutritious food loved by many people, especially young children. The above knowledge helps you understand what is the cleanest food you should consume in order to have the healthiest possible life.

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