Why do potatoes turn black inside during storage?

Content

1 Why are there dark spots on potatoes (grey rot)
2 Conclusion

Potatoes are a traditional vegetable for Russians. It is grown in almost every garden, and with the arrival of autumn it is put into bins for long-term winter storage. But unfortunately, often potato tubers turn black during storage. And even seemingly healthy vegetables may have black spots when cut. Why potatoes turn black during storage remains a mystery for many farmers that must be solved. Otherwise, the problem will arise year after year, destroying kilograms and tons of harvested crops.

Why are there dark spots on potatoes (grey rot)

In the cross-section of some tubers you can see blackening of the pulp. An example of such a change is shown in the photo above. This defect is a sign of gray rot of tubers. It can occur due to a number of reasons. As a rule, they are associated with a violation of the storage or transportation regime of vegetables. Experts identify 6 main reasons why potatoes turn black inside during storage:

Unbalanced soil composition

Many gardeners, in an effort to get a good harvest of vegetables, add large amounts of organic matter to the soil. This can be manure, herbal infusion or green manure.Such fertilizers contain a large amount of nitrogen, which accelerates plant growth and allows you to grow a large mass of tubers. However, it is the large amount of nitrogen that is the main reason why potato tubers turn black during storage.

This cause can be eliminated through proper application of fertilizers:

Fresh organic matter cannot be used for potatoes. It should be well rotted. This applies not only to manure, but also to green manure.
Adding manure to the soil for growing potatoes is allowed no more than once every 2 years.

Focusing on the use of nitrogen, many gardeners forget about such an important trace element as potassium. But it is potassium that allows the tubers to ripen in a timely manner and be safely stored during the winter. So, to prevent blackening of tubers, it is necessary to regularly add potassium fertilizers to the soil.

Important! The best keeping quality is demonstrated by mature medium-sized potato tubers.

Weather features

Potatoes prefer to grow in conditions with moderate temperature and humidity. Fluctuations in these indicators negatively affect the quality of tubers:

high temperature leads to overheating of tubers;
low temperatures slow down the process of nutrient absorption from the soil, resulting in the formation of small vegetables;
lack of moisture dries out the tubers;
Excess moisture does not allow potatoes to breathe oxygen to the required extent, as a result of which various fungal and bacterial diseases and rot develop.

Each of these unfavorable conditions and their complex can lead to the fact that potatoes during storage begin to turn black inside and lose their consumer qualities.

Late cleaning

Potatoes must be harvested from the field on time. Every experienced farmer knows this rule. Harvesting unripe crops and harvesting potatoes with the onset of frost can lead to dire consequences during storage:

Harvesting must be carried out in accordance with the characteristics of the variety. Harvesting unripe tubers too early will most likely lead to blackening of the potatoes during storage;
potatoes need to be collected from the fields before the first frost. Temperature even -1⁰C can cause the crop to freeze, causing it to rot during storage;
In warm sunny weather, potatoes cannot be stored in the soil for a long time after mowing the tops. Without access to moisture, it may overheat;
bags of potatoes cannot be stored in conditions with elevated air temperatures. Optimal mode for packaged vegetables +2-+4⁰WITH.

Timely harvesting of potatoes will reduce the likelihood of black spots appearing inside the fruit during storage by 25%.

Mechanical damage

During harvesting and transportation, potato tubers are often hit, which leads to mechanical damage and bruises. The pulp in deformed areas of the fruit may change color during storage. It is also important to remember that damaged areas of the skin are “gates” for various viruses, fungi, and bacteria, which can also cause putrefactive diseases of root crops.

Important! Potatoes should be stored in small containers in several layers.

Great pressure on the lower layers of the potato can cause black spots to appear inside the fruit.

Storage violation

You can store potatoes in a cellar or basement at a temperature of +1-+4⁰WITH.Long-term storage of tubers at a temperature of 0...-1⁰C leads to sweetness in taste and the formation of dark spots inside the pulp. Storage temperature too high (more than +5⁰) leads to rapid germination of tubers and the appearance of gray rot.

It is necessary to monitor the temperature in the storage regularly, however, special attention should be paid to this indicator in the fall and spring, when there is a change of seasons. You can regulate the temperature by opening (closing) air vents, ventilation, and placing bottles of cold (hot) water around the perimeter of the room.

You can learn more about all the features of storing potatoes from the video:

Infectious diseases

A disease such as black leg can affect not only the tops, but also potato tubers. Moreover, the first symptoms of infection may appear only during crop storage. A sign of the disease is rot, which quickly spreads from the stolon to the core of the tuber, covering the entire fruit. At the same time, rotting fruits emit an unpleasant characteristic odor. This black rot inside potatoes is different from the usual gray spot. Its peculiarity is its rapid spread within one tuber and infection near nearby vegetables.

It is worth noting that most often potatoes turn black if they contain a large amount of starch. Thus, slightly blackened flesh is the norm for some potato varieties.

Conclusion

To prevent potatoes from turning black during storage, it is necessary to strictly follow the rules of growing the crop and ensure an optimal microclimate in the cellar. For preventive purposes, it is necessary to apply potassium fertilizers to the soil at a late stage of plant growth.You can smooth out the negative impact of weather conditions during cultivation if you do timely loosening of the soil, weeding, and hilling of plants. With maximum effort and attention, you will certainly be able to not only grow a good potato harvest, but also preserve it without loss of quality until late spring.