The listed preventive and control measures will help prevent the development of scab on apple and pear and get the harvest in full. The content of the article:
- How does scab appear
- Scab prevention
- Treatment features
- Comprehensive treatment
Scab of pears and apple trees is a fairly common disease that leads to spoilage of a large part of the crop. If preventive measures are taken in time, then this harmful fungus may not appear at all.
How does apple and pear scab appear?
It is interesting that although the name of this stone fruit disease is the same, the pathogens, microorganisms, are different. Therefore, if the apple tree is sick with scab, and a pear is growing nearby, then the apple fungus will not spread to it. The pear is threatened by scab caused by microorganisms that prefer to have a harmful effect only on this tree.
If you want to make sure that the fruit was hit by the scab, the photo will help you with this. To recognize it early on, look at the leaves. If yellowish oily spots appeared on them, and then they began to become covered with a velvety coating of greenish-brown color, then it is a scab. If the disease manifests itself in the fall, the spots will be small - 2-3 mm, and in the spring they are larger - up to 1-1, 3 cm in diameter.
If you do not take urgent action, the disease will affect flowers, fruits, and even branches on the pear. That is why scab on a pear can appear already in spring, since harmful fungi winter not only on fallen leaves, but also on branches. On fruits, the disease manifests itself in the form of rounded, almost black or dark gray spots. The site of infection becomes dense. Its corking delays the growth of the fetus, so the affected pears and apples grow lopsided.
Cold and rainy weather contributes to the onset of the disease. The process itself and the degree of infection depends on the humidity and air temperature. To a greater extent, this is influenced by humidity. Therefore, even in dry and hot summers, scab can appear if abundant dew falls at night.
Prevention of apple and pear scab
To prevent scab, it is necessary to destroy the infected leaves. After autumn leaf fall, they can be buried in the ground of the trunk circle, burned, and composted. If you didn't have time to do this in the pre-winter, then do not forget to remove the leaves in the spring. And in a pear, it is necessary to cut off the affected branches.
Trunk circles need to be freed from weeds, mulched with humus or peat.
The crowns of trees should be blown by the wind in wet weather, well illuminated by the sun. Therefore, you should annually prune the crown, removing dry, diseased branches and those that thicken the tree.
Features of the treatment of apple and pear scab
One of the measures that helps in the fight against scab is tillage of the soil along the near-trunk circle with solutions of mineral fertilizers of high concentration in the spring before the buds bloom on the trees.
To do this, 165 g of urea or 250 g of potassium chloride or 250 g of ammonium nitrate are dissolved in 2.5 liters of water. This amount of solution is enough for 10 m2 area. Only the soil is cultivated along the trunk circle. To prevent burns of the tree, make sure that the product does not get on any part of it.
For the prevention and control of apple and pear scab, you need to do several sprays. The first is done before bud break or during bud extension. To do this, dilute 40 g of lime, 30 g of copper sulfate in 1 liter of water.
If you did not manage to process it within this period, then before flowering, spray with a Bordeaux mixture, diluting 20 g of lime, 20 g of copper sulfate in 2 liters of water. This amount of funds is enough for a young tree, and for an adult fruiting one, 4–5 liters of solution will be needed.
The second treatment must be carried out immediately after the end of flowering, diluting 2 ml of the "Skor" preparation or 40 g of the "Abiga-Peak" preparation in 10 liters of water. It can be sprayed with Bordeaux mixture at a concentration of 1% or with other preparations of a similar effect.
The third treatment is carried out 2-3 weeks after the second, using the same preparations as for the second spraying.
Better than other fungicides in the treated areas of the tree, the Bordeaux mixture is retained. It protects plants for up to a month. But during the period of fruit development, such preparations, which contain copper, can cause burns on the fruit, especially if there is high humidity.
Recently, long-acting drugs have been created. Horus protects trees for up to 30 days, moreover, it is not washed off by rain. Its effectiveness is especially evident at low temperatures - + 3 + 10 ° С. You need to process it 2 times per season - during the budding period and at the end of flowering.
The action of the drug "Strobi" is even longer - up to 35 days. In addition to treating pear and apple scab, it also helps to get rid of powdery mildew. During the growing season, up to three treatments are carried out with an interval of 2 weeks. This tool can be used along with other similar fungicides.
Comprehensive treatment of apple and pear scab
It helps you achieve the best results. Before autumn leaf fall, after harvesting, trees should be sprayed with a solution of any of the fertilizers presented below: ammonium sulfate, ammonium nitrate. These drugs are used at a concentration of 10%. The concentration of the following is 3-10%, it is potassium sulfate and potassium chloride. And at a concentration of 5-15% potassium salt or potassium nitrate is diluted.
It is necessary to process when the air temperature has not dropped below + 4 ° C. Then such spraying will contribute not only to the destruction of scab, but also other dangerous fungi and various pests, and will increase productivity. In spring and summer, treatments are performed against scab, which were described above.
Planting varieties of pears and apple trees that are resistant to it will help to avoid the disease. Remember that early apple varieties are more affected by scab.
Early varieties of apple trees include:
- Grushovka Moscow;
- Melba,
- Pink filling;
- Lobo;
- Mekintosh;
- Borovinka;
- Mantet.
Apple varieties that better resist scab:
- Welsey;
- Cinnamon new;
- Pepin saffron, etc.
Pear varieties that are more resistant to this disease:
- Chizhevskaya;
- Lada;
- Space;
- Severyanka.
If preventive measures are used in time against apple and pear scab, at the first signs of its manifestation, the correct fight is carried out, then the disease will certainly recede.
How to deal with apple and pear scab - watch the video:
During rainy summers, during periods of bountiful harvests, many nutrients are washed out and carried away from the topsoil. Trees in such conditions are more susceptible to diseases, they tolerate frost worse. Constant application of organic and mineral fertilizers will help to avoid this.
