Causes of leaf curling in potatoes
In addition to the well-known phytophthora, nightshade crops can be subject to many other diseases. Leaf curling in potatoes is a fairly common problem. To understand how to cure plants, you need to determine the reasons for this phenomenon.
Causes of leaf curling in potatoes
Twisting reasons
Why do potato leaves curl? There can be several reasons for this phenomenon.
- The use of herbicides.
- Improper care.
- Diseases: viral, bacterial.
To understand why potato leaves curl, you need to look for accompanying symptoms. If this is a disease, then curliness, will be accompanied by the formation of spots of various shapes of dark color, brittle shoots, stunted growth and other symptoms.
Herbicides
Herbicides are chemicals used to remove unwanted vegetation in an area. They can be directional and general. Directional drugs destroy certain types of plants, and in general they affect all crops.
When herbicides of general action hit the soil or the bushes themselves, the leaves of the potato curl. Even if a herbicide has not been applied on your site, it can be brought by a stream of wind from neighboring fields. It is recommended to use herbicides in the autumn when preparing the soil for planting, but not during the period of crop growth.
Improper care
Often, potatoes are curly due to non-observance of the rules of agricultural technology. Often, this is too abundant watering or lack of moisture. If the bush is lethargic, this does not mean that it needs to be flooded.
With an excess of moisture, the metabolism in the tops is disturbed. The plant cannot absorb this amount of water, so moisture accumulates in the air sinuses, underground. As a result, small roots begin to rot, the deciduous part curls.
Viral diseases
Curly foliage can be caused by mosaics. The virus destroys up to 70% of plants. The edges of the leaves of the upper tier become wavy. The disease does not affect the lower layer of foliage. The infection is transmitted mechanically, often insects are carriers.
If the leaves of the potato begin to curl vertically, along the middle vein, it is a symptom of the curling virus. The structure of the greenery becomes tough, its inner part is colored purple. The growth of the bushes slows down significantly, the tops change their color from a rich green to a paler, almost white. The disease progresses in arid conditions. The infection persists in tubers, most often during planting.
Stolbur disease at the very beginning is manifested by chlorosis of the deciduous part of the upper tier. Then the potato leaves are rolled to the core. The development of the deciduous part slows down sharply. Bushes become small-leaved. Subsequently, chlorosis begins to manifest itself on the leaves of the lower tier, as a result, the bush withers, and processes similar to threads are formed on the tubers.
Bacterial diseases
Disease can ruin crops
Most often, potatoes are affected by the black leg. The twisting of potato leaves begins from the top, after which blackness appears at the base of the stem and the rhizome rots. The disease destroys 50% of the plants.
Curly potato leaves can be a symptom of black scab. The plant begins to slow down its growth at the initial stage of growth. The spores of the fungus persist in the soil and on the seed. Curling of leaves on young shoots is the first symptom. Then the stem and root system rots, as a result of which part of the seedlings perishes.
The fungus remains in the soil and progresses on all remaining specimens. With the defeat of black scab, ulcers with a diameter of 2 cm appear on the root crops. The crop cannot be stored, the roots quickly begin to rot.
The scab can be of several varieties.
- White leg - on the stem, a white bloom in the form of a cannon appears at the base. It progresses in warm, humid climates.
- Root spotting - manifests itself in rainy, cold weather. Round brown spots form on the tubers. This symptom can be easily confused with wireworm damage.
Treatment
Treatment will depend entirely on the cause of the metabolic disorder. If the potato leaves are curled due to the use of herbicides, then nothing can be done. It all depends on the amount of the drug that got into the soil and on the plants themselves. If there are industrial fields nearby and herbicides were sprayed from a helicopter, then, most likely, the yield will decrease by at least 50%, and most of the plants may die altogether.
If the twisting is the result of improper care, the situation can always be corrected. With waterlogged soil, it is recommended to deep cultivate the row spacings. If the lower leaves have already begun to rot, they must be removed so that the rot does not creep up. In arid climatic conditions, to retain moisture in the soil, mulching is carried out with grass or foliage. For the treatment and treatment of plants, a solution of copper sulfate is often used.
Preventive measures
To prevent potatoes from being attacked by pests and all kinds of viruses, all seed material must be disinfected before planting. The main method of fighting viruses and bacteria is observance of the rules of crop rotation. You cannot plant potatoes for several years in a row in one place. Throughout the growing season, spraying with fungicides and antibacterial drugs is carried out. The chemical preparations Baktofit, TMTD, Polycarbocyte, Fitosporin, Prestige, Maxim have proven themselves well.
Chemicals have a complex effect against all types of diseases. Processing is carried out 3 times:
- before boarding;
- during the emergence of sprouts 20 cm;
- at the beginning of the emergence of buds.
Before planting, you can use a solution of manganese or boric alcohol. All work with chemicals should be carried out according to the instructions. The main thing is to have time to carry out the processing before flowering. No chemicals are used during flowering. After infection with one of the diseases described above, potatoes in this area can be planted again only after 6 years, not earlier.
Conclusion
Curled leaves on potatoes are a very common occurrence. The reasons can be very different, but the main one is non-compliance with the rules of agricultural technology. Many gardeners neglect the crop rotation system and do not pay proper attention to the pre-treatment of tubers before planting. Many infections and fungal spores can persist in the soil for several years, remain on tubers and be carried on the paws of insect pests.
Potato leaves begin to curl when metabolic processes are disrupted. This may be due to a lack of vitamins, soil acid, drying out or waterlogging of the soil. It is far from always possible to save the harvest.If affected by many ailments, it is advisable to immediately remove all affected bushes, burn them. On an infected site, you should not plant nightshade crops for 6 years.
The impetus for the development of bacterial and viral ailments is too hot and humid weather. Fungal spores and virus cells begin to multiply rapidly under such conditions. In the process of reproduction, pathological cells absorb nutrients from the foliage, externally this manifests itself as twisting.