Why potatoes blackened inside

Blackened potatoes inside – this is not a normal external pitchfork, normally this should not be. Most often, such spots appear due to the fact that mistakes were made during cultivation, as well as during the storage of potatoes, however, it also happens that gray spotting is a consequence of the development of a disease. Let’s take a closer look at why potatoes turn black and how to deal with this condition.

  • Too much nitrogen in the soil, or same potassium deficiency. Also, undiluted organic matter added to the ground can cause darkening of the pulp, potatoes do not like the introduction of concentrated products;
  • During cultivation, mistakes were made in irrigation, this can be either overflow or underfilling;
  • The crop was harvested either too early, or, conversely, late. In the first case, the tubers simply do not have time to ripen, in the second – they are too long in the warm earth and rip.

Blackening during storage

Quite often the potatoes turn black inside during storage, we will find out why this happens:

  • The potato becomes covered with dark spots when it is in a warm place or in a room with insufficient ventilation for a long time.Usually, the first manifestations appear after 1-2 months of improper storage;
  • The normal temperature for storing potatoes is considered to be a range from 2 to 4 degrees with a plus mark, if the temperature is lower, the vegetable freezes, if higher, dark spots may appear .

In addition, it is worth mentioning that blackening of the pulp can occur due to the fact that you planted a variety in which there is too much starch. The fact is that it is these varieties that suffer from this problem, most often this manifests itself during cooking of the vegetable.

Blackening due to cultural diseases

As mentioned earlier , the cause of the appearance of dark spots can be one or another disease, we will find out why the potato can turn black inside, what diseases contribute to it:

Black leg

This is an infectious disease, which is transmitted from an infected tuber to a healthy one. Moreover, the further spread of the disease can occur already in bags, when the potato crop is already harvested and the fields are empty. Externally, such a state can be distinguished from gray spotting, because from the inside the tuber will already blacken from stalon. Black spots initially cover the middle of the potato, later move to the vascular branches, appearing on the peel. Also a distinctive characteristic of the disease is a characteristic unpleasant putrefactive odor. It is important to detect the problem at the growing stage in time to prevent the spread of the disease.


Next, we will talk about a disease such as melanosis. Outwardly, the tuber and peel of the affected culture will usually look unchanged, however, at this point, blackness continues to increase under the peel. It is worth saying that the affected vegetables remain suitable for food, which can not be said about the previous disease – the black leg. In order for the spots not to increase in size and the cooked dish looked more attractive or appetizing, you need to add vinegar and citric acid to the water during cooking, while peeling is not necessary.

Causes of the appearance of melanotic spots can be different, for example, mechanical damage to a vegetable.

Most often, melanosis affects potato varieties with a high starch content in the pulp, it becomes darker most often. In addition, the development of the disease is accompanied by errors in the selection of the harvest date. It’s worth it to be competent in this aspect and to do everything so that you don’t injure the tubers during harvesting.

Причиной болезни может стать повышенная влажность

The cause of the disease can be high humidity

An excellent prevention of melanosis is to bag the beets in potatoes, it helps to keep the potato pulp intact. The fact is that beetroot will help overcome the problem of excessive moisture in the storage area of ​​tubers.

late blight

Another cause of the appearance of such spots on the pulp may be late blight. This disease has a place to be in any region, including the entire territory of Russia. A distinctive feature of the disease is that it affects not only the tuber, but the leaves of the plant. This fact significantly complicates the fight against the pest. If preventive measures are not taken in time, there is a chance that the fungus will be able to infect all plants and crops growing in the garden or field.

Signs of late blight

  • Brownish spots form on the leaves and dots
  • The leaves rot and then dry out
  • The final stage is their decay

Causes of late blight

Infection with late blight as follows and for such reasons:

  • The remains of the weed and other vegetation were not promptly harvested
  • The seedlings were worn out initially infected with a fungus
  • Mistakes were made in the technology of growing potatoes.

It should be said that the magnitude of the defeat of late blight is impressive, the disease spreads very quickly. The peak incidence occurs during the flowering period of the bush, although in most cases the infection period may shift in one direction or another, depending on weather conditions. The most favorable time for the multiplication and spread of the fungus is wet and damp weather, rainy autumn or thaw in spring.In addition, the spread of infection will be facilitated by excessive watering of potato bushes, thus, pathogenic microflora will move along with moisture through the soil. It is worth mentioning that, despite the fact that late blight is a danger to the future harvest, the disease significantly increases the chances of infection with other ailments, for example, a variety of fungal diseases or wet rot.

Prevention of late blight

In order to preserve and protect your crop from late blight, you need to know all preventive measures, because they are quite simple, unlike getting rid of a disease that involves getting rid of infected bushes. We will try to list the main preventive measures that every farmer should know:

  • You should not cover the harvested potatoes with tops. If there are infected leaves, there is a risk that the disease will soon switch to tubers
  • Harvest depending on the type of potato. So, earlier varieties should be dug earlier, without waiting for the density of the peel, later ones later.
  • Follow the watering standards, do not forget to add fertilizers to the soil in time.

Potato is sick
potato diseases and control measures
Potato disease

Methods of struggle

What to do if, despite all preventive measures, they are sufficient care tops of potatoes still was black? In this case you should throw all the forces out to fight the disease as quickly as possible until the problem has become more global. If you find a slight blackening of the leaves on the potato bush, take the following measures:

  • Spray the leaves of the potato with Bordeaux mixture or copper oxide with chlorine, usually a seven-day treatment is enough to solve the problems of blackening the potato once and for all.At the same time, each leaf is processed, and it is necessary to do this from two sides
  • If you find the disease at an advanced stage, that is, the potato bush has turned pretty black, there is not a single green leaf left on it, it makes no sense to save it
  • After all of the above actions have been carried out, it is necessary to mow and further destroy all the tops that were affected by the disease, and they do this strictly 7 days before the harvest.
  • After Once the crop is harvested, it is important to ensure normal storage conditions. Culture tions, ie to comply with the requirements concerning ventilation, temperature and lighting. It is important to re-check the crop after 2-3 weeks of storage of the crop to exclude black tubers.

Now you know why the potatoes turn black inside during storage. In conclusion, we say that blackening of potatoes is quite common, it is enough to follow all the requirements for growing and storing the crop, choose varieties of potatoes with a normal starch content, thereby reducing the risk of problems for a minimum.

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Anna Evans

Author ✓ Farmer

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