Powdery mildew on an apple tree
A gardener needs to regularly look after apple trees, because if prevention is not constantly carried out, fungi and pests will attack the trees. One of the most common such ailments is powdery mildew on an apple tree.
About powdery sundew
Trees and shrubs often suffer from the disease. The disease progresses with excessive humidity and warm temperatures + 18-25 ̊С. If the apple tree matures in such conditions, then it is less resistant to diseases. With the heat in the summer, the sundew begins to gradually turn black and transform into a fungus. The disease no longer develops. Layering the fungus dies, the virus continues to develop in the buds of the apple tree at hot temperatures.
Causative agent of the disease
The instigator of an infectious focus is a fungus that completely infects the plant, including also foliage, young buds and bark. The most key factor in the manifestation of the disease is the appearance of a whitish coating on young leaves and shoots. Over time, the flooring turns brown and covers with dark spots. The affected areas lose their original shape, twist and wither. Shoots no longer grow, curl up and dry out. The disease worsens the general condition of the apple tree. Fertility drops sharply, foliage falls ahead of time. In frost, the sundew develops poorly.
Attention: The fungus disappears at -20 ̊С. After large frosts, the signs of the disease go away.
The disease has 2 ways of development:
- First stage. Whitish bloom on apple trees Are conidial spores. The first stage of the disease can be seen in March-April when the buds open. The apple tree at this moment clings to the fungus, which hibernated in the ovaries. Conidia are formed. The primary stage lasts about a month.
- Marsupial stage. Develops in early June. Dark spots form on foliage and shoots.
The main disease covers the entire apple tree, leaves, branches, fruits, flowers are affected. Initially, the leaves are hit first, they are covered with a white bloom. Those places that are affected do not grow, discolor and fall off. The plaque becomes dark, the shoots grow more slowly. About half of the young branches freeze out. A whitish coating forms on the hands, which dries instantly. The inflorescences dry out and lose their shape. The fruits are also susceptible to damage.
Disease Resistant Varietal Varieties
When planting apple trees, it is better to acquire varieties resistant to powdery sundew. The best are:
Important: This measure will help save about 80% of the fruits.
Why does powdery mildew occur on an apple tree
The main reason for the occurrence is considered to be high humidity. But a lack of moisture can also cause sundew, the plant's immunity, as a result, will weaken. During winter, the fungus lives in infected buds or foliage and branches. In windy conditions, condia will spread to healthy plants. The sundew can be seen during the flowering period. On average, the period of latent development of the disease lasts about 10 days.
How to fight infection
When infected with powdery mildew, the fruitfulness of trees drops significantly. The foliage falls off ahead of time, the loss of fruits is about 60-70%.
To defeat the sundew, you must first remove diseased shoots in the spring and winter. The procedure is carried out at the time of bud break and after the apple tree has faded.
Attention: After pruning, the infected branches must be burned, since the fungus is very tenacious. They can spread over many hundreds of meters without problem.
Also, for powdery mildew, spraying with special preparations can be carried out. The procedure is carried out during the period of budding and flowering, but you can spray it after the apple tree has flowered. Several operations need to be done during the season. Processing is carried out 1 time every 7 days. If disease-resistant varieties are planted in the garden, then the plant can be sprayed as needed. The apple tree must be treated with chemicals before the leaves appear.
Alternative treatment methods
Very often, the disease is fought with folk methods, for example, the following:
- Cleaning of affected branches;
- Digging soil in the near-shaft zone;
- Feeding the plant with fertilizers, which include phosphorus and potassium;
- Spraying apple trees with decoctions of poisonous plants.
Soda. A popular remedy among the people. You can make the following broth: add 100 g of laundry soap to 10 liters of water. Pour in 2 tablespoons of baking soda, mix. The plant needs to be processed 3 times every 10 days.
This is one of the most effective methods of fighting the disease. It is necessary to add fertilizers to the area near the trunk with a diameter of 2 meters. Organic, potash and nitrogenous fertilizer materials can be used.
Sundew control methods
To save the plant, perform the following actions:
- Chemical treatment;
Important: To avoid problems with the apple tree, you first need to get a good tree.
Preventive measures do not always save you from infection.
When and why to carry out processing
Very often, experienced gardeners use chemicals to combat the disease. It is recommended to purchase the following products: Topsin, Topaz, Colloidal sulfur, copper sulfate.
If the plant is severely affected, then drugs that include flutriafol, penconazole and tebuconazole can be used. For the first time, the plant is treated during the division of the bud, the second time after the apple tree blooms, and the last time after 2 weeks.
Also, in dry weather, you can carry out the treatment with Hom or copper oxychloride.
Tebuconazole. It actively penetrates the plant, is able to fence off the disease for a month.
Urea. Granular product with nitrogen content. To feed an apple tree, you need to dilute 200 g of the product in 10 liters of water.
Fitosporin. Eco-product. Processing is carried out once every 14 days. If it's rainy outside the window, then the plant can be processed after three hours before the rain starts or at the end.
Impact. The product is slightly toxic. Do not use during the flowering period. The remedy saves from fungus for a month. You can use it in March or November.
Cumulus. The tool actively fights against fungal diseases, the tool is granular. In hot weather from 28 degrees, the remedy does not work.
To avoid the occurrence of powdery mildew, you need to properly lay the garden.
For prevention purposes, the following measures should be taken:
- Trim from time to time so that the crown is not thickened;
- Humidification of trees;
- Cleaning up affected shoots;
- Cleaning of fallen leaves;
- Digging of the near-stem zone;
- Selection of apple varieties;
- Chemical treatment late autumn.
In order for you to have a good and healthy garden, it must be regularly and thoroughly looked after using the recommendations above. Then such an attack as powdery mildew on an apple tree will bypass you.