Diseases and parasites lead to a partial or complete loss of crop. Alternariosis, or dry spotting of potatoes, is a common disease that affects the plant.
In order to get a good crop and preserve potatoes, you need to know about the causes and ways to combat this disease.
Causes and harm
Alternariosis affects leaf plates, due to which the physiological process in the tuber-forming tissues is disturbed. As a result of the disease, not only the aerial parts of the potato suffer, but also the tubers die. Fungal infection spreads rapidly, and therefore can affect neighboring areas.
The causative agent of the fungus tolerates low temperatures well and can be transported not only with the wind, but also through the ground. To preserve the potato crop, it is necessary to recognize the disease in a timely manner and take the necessary measures: apply fertilizers, regulate watering and dig the soil well.
Symptoms and signs
Unlike other fungal diseases, alternariosis is easy to
- Brown spots appear on the leaves. Over time, in the affected areas, the stems begin to dry, twist and die.
- The appearance of spots indicates that the infection occurred 2-3 days ago. On day 3-5, the lesion area increases and platinum sheet becomes thin and brittle. Due to the drying of the tops, the nutrition of the tubers is disturbed, as a result of which the underground part suffers.
- Black spots with distinct parallel wrinkles appear on the surface of the tuber peel. The pulp of the tuber hardens and darkens. Potato spotting is widespread in the central and southern regions. Active sporulation is observed in early spring, when the length of potato tops grows to 15-20 cm. In hot weather, spores die, but this does not guarantee infection of plants later. Mass manifestation is observed during the appearance of buds in the lower and middle tiers.
Prevention and control methods
The best way to avoid infection is to choose a quality planting material. The most resistant varieties to spotting potatoes are: Nevsky, Dolphin, Spark, Bryansk Delicacy, Fairy Tale.
The second measure to help prevent the spread of the disease is to eliminate the primary infection. It is necessary to timely process the planting site, remove weeds and infected plant debris. A good preventive measure is to plant green manure.
When and how to process
The most effective method of combating the disease is chemical treatment. To eradicate alternariosis, up to 4-6 treatments in case of mass infection and 2-3 in moderate distribution may be required. A deficiency of potassium and nitrogen in the soil can provoke the spread of infection.
Suitable for prophylaxis:
- Copper sulfate.
- Bordeaux fluid, etc.
Regular treatments, as well as precautions will help to avoid infection, maintain and increase yield. All chemicals must be diluted and used only according to the instructions.