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Cultivation of crops requires proper care for the future harvest. Potato diseases can cause serious damage if the necessary measures are not taken in time. What diseases do farmers face and how to deal with them?
How to deal with phytophthora on potatoes? Causes of the disease
The most popular disease is late blight. Its prevalence does not depend on the region of the country. The defeat of the disease reduces potato yield by 50-70%.
In the photo, the late blight of potatoes - the causative agent affects the tubers to a greater extent, but the ailment also appears on the tops. By its nature, the causative agent is a mushroom-like organism, resistant to temperatures from 1 to 30 degrees. Spores get into the ground, after which they hit the tubers. Infection can occur during harvesting - spores from the ground surface are transferred to the tubers. Infection occurs through any mechanical damage. The best conditions for the development of the dispute are moisture.
Why do the leaves turn yellow? One of the reasons is the phytophthora. Visual manifestations are the appearance of brown spots on leaves and stems. On the reverse side of the sheet may form a plaque, similar to cobwebs. On the tubers - spots-necrosis brownish-brown color. This disease is almost impossible to cure if the focus has already developed, therefore the main measures of the struggle are prevention.
How to deal with phytophthora on potatoes? A number of measures for the prevention and treatment of this disease have been developed:
- Before boarding:
- The main thing is to remove the affected tubers from the seed material, which serve as the main source of disease for the whole future crop. The material for planting must fully comply with all standards.
- It is important to choose the right place for growing the crop.
Pay attention: the place for planting should not be in the lowland, it is good to dry out after precipitation! Stagnant moisture contributes to the development of phytophthora:
- Think about the planting sites of other crops - potatoes can be infected from tomatoes that are also susceptible to this disease.
- If there are other people's vegetable gardens nearby, it is worth paying attention to the fact that there are no beds with tomatoes.
- It is recommended to germinate tubers before planting.
- Special treatment is necessary with special preparations. Phytophthora "does not like" copper, so it is best developed in soils that are poor in this chemical element.
- Combating phytophthora during the growing season:
- It is recommended to treat the soil against possible infection and weeds. Do not wait for the appearance of symptoms - use a fungicide.
- Planting high ridges reduces the likelihood of infection on the potato bush.
Preventive treatments do not make sense, if the foci of the disease have already formed.
Processing of potatoes from phytophthors should be carried out with the help of chemicals 1-2 times per season. 2 weeks before harvesting, it is necessary to remove the tops chemically - this will protect the tubers from contamination during harvesting.
- During and after harvest:
- It is recommended that the harvest be harvested no later than 14 days after the death of the tops.
If during the withering period the rains are raining, moisture can promote the development of phytophthora - harvesting should be faster, but not during the rain.
- If the crop is wet for various reasons - ensure a good aeration to make the tubers dry completely.
- Before you put the harvest in the vault, go through it - you need to identify and remove the infected tubers.
Black scab: methods of disease prevention
One of the most common diseases is black scab or rhizoctonia. This pathology has a surprisingly wide range of distribution. The causative agent is a fungus, which causes loss of moisture tubers. Signs of the presence of the disease appear at the stage of flowering potatoes. Development of pathology best occurs at a temperature of + 16 +18 degrees, humidity - 70%. In contrast to phytophthora, the level of harmfulness of the scab depends on several factors:
- the amount of fungus in the soil;
- quality of seed;
- type of planting - the density of the arrangement of potato bushes;
- conditions of potato growth;
- type of soil - the infection develops best on loams;
- the most important thing is that the optimal level of acidity of the soil coincides with the ideal index for the development of potato tubers.
The scab affects all parts of the bush and tubers:
- On the tubers the scab is manifested in the form of spots, mesh necrosis, which develops in hot weather. Deepening and pits are formed in conditions of excessive moisture.
- Sprouts can form rot - the effect of "rotten wood".
- The stem of a plant affected by the disease can be impressively lower than the rest.
- In wet and warm weather, a "white stem" of the stem is formed.
In some cases, damage to seedlings is possible, because of which the bush dies before reaching the surface of the soil. The level of harm of the disease: 10 to 40% of the crop perishes, on an industrial scale - the scab considerably worsens the appearance of the produce.
Potato diseases and combating them require decisive measures - first of all, preventive. It is worth considering not only how and how to treat the soil, but also where to plant potatoes.
- It is best to plant potatoes on the spot where before they grew: flax, rye, canola, corn, grasses-perennials.
It is not recommended to plant after cabbage, beet, pumpkin, tomato, clover. These cultures contribute to the development of black scab. Planning crop rotation is the main agrotechnical measure of disease control. Modern development allowed to develop varieties that show resistance to the disease.
- It is recommended to use chemical agents - to treat with a fungicide. Chemical warfare is considered the most profitable and effective method. It is possible to process both seed material and soil.
There are many types of scab, but the methods of fighting it are similar.
L-potato virus: fighting methods
Why do potatoes twist the leaves? The cause of this phenomenon can serve as a leaf twisting virus, which can destroy from 20 to 70% of the potato harvest. A disease of aphids that transmits pathogens is transmitted. The development of the disease contributes to wet weather. Symptoms are:
- The plant grows light, and the top leaves of the bush twist.
- The leaves become brittle and rustle strongly.
- The reverse part of the sheet becomes white-silvery.
Fighting the disease requires complete removal of the infected potato from the seed and harvested crop, as the infection persists in the tubers. The main preventive measures are the cultivation of soil and potato bushes with means from aphids, which carries the infection.
Ring rot: symptoms and methods of struggle
A common disease that affects all parts of the plant. The most common signs of the presence of the disease are wilting the leaves and decaying the inside of the tuber. Visual signs can be seen at the stage of vegetation of the plant. The development of the disease deprives the stalk of the possibility of obtaining moisture, because of which wilting is observed.
To infect a healthy plant or tubers is easy. The causative agent easily hibernates in the infected potatoes, and the seed can be infected while cutting the tuber with a knife. The affected potato is difficult to visually distinguish from healthy, especially if the pathology is underdeveloped - it is enough to cut the tuber to see the yellowing of the ring and the formation of extensive rot.
Methods of struggle:
- Fulfillment of all the rules of crop rotation.
- It is necessary to remove the tops in time.
- Before planting, it is necessary to dry the seed material - for 2 weeks at a temperature of at least +15 degrees.
- After drying, it is necessary to identify the affected material.
Various diseases of potatoes (photo), the description and treatment of which is described above, require timely prevention.