Scabies and methods of protection against it

Scabies is an infectious disease that poses a great threat to many cultures. The causative agents of this disease are pathogenic microscopic fungi, bacteria and actinomycetes. In a plant affected by scab, deformation of the surface of leaf plates, tubers, stems and fruits is observed, which has a very negative effect on yield. The most widespread distribution of this disease is observed in temperate climates. There is scab, due to which shrubs and trees suffer, and there are also types of such a disease, the lesions of which are prone to beetroot and potato root crops.

Features of the disease

Experts noted that crops are affected by various scab pathogens. For example, scab on an apple tree will never spread to a potato or pear. However, all types of this disease have common symptoms. When examining a sick plant, the following symptoms of the disease can be detected: the skin begins to peel, pustules, spots, warts and ulcers form on fruits, tubers, shoots, leaf plates, stems and flowers. If the plant is severely affected by scab, then there is drying and falling of the leaves, a violation of the water balance of the crop, and this has a very bad effect on the fruiting of both the current and future seasons. There is also shedding of diseased flowers and buds, and the fruits become ugly due to this disease. In addition, during storage, such fruits begin to rot, as it is very easy for rot pathogens to penetrate into them through cracks formed on the surface of the skin due to scab.

Cultures are affected by such an infectious disease only under certain conditions. For example, increased soil moisture. This disease cannot develop without moisture. The fungus is activated when the snow cover rises in the spring, while the air temperature should be about 12 degrees. Scabies starts to develop during the summer if it rains often or there are frequent fogs and dews. And the development of the disease is facilitated by excessively thickened planting. In those garden areas where many trees of the same species grow, the rapid spread of the disease is noted, especially if the surface of the soil between the rows is overgrown with weeds, which, like a bridge, transmit spores from one plant to another.

Also, the rapid spread of scab through the garden is observed even with genetic uniformity, for example, when trees of the same species grow close to each other. If a plum or pear is planted next to an apple tree affected by scab, all of them are unlikely to be "infected" by the apple tree. And if 2-3 more apple trees grow near the diseased apple tree, then all these plants will be affected by scab after some time. Also, some plants are more often affected by scab due to the susceptibility of the variety. Thus, experts found out that some varieties are less likely to get scabies, and others more often (due to their high susceptibility). To date, breeders have managed to obtain varieties with high resistance to scab.

Fight against scabies

How to treat scabies

Chemical agents deal with scabies most quickly and effectively. And in some cases, chemical fungicides are the only hope for saving a sick plant.
To get rid of scab, you need several treatments, and it is very important to choose the right timing for spraying plants. And in order to do this, it is necessary to know what time falls on the beginning and end of the spread of ascospores of the fungus.

Plants are sprayed for this disease for the first time in the green cone phase, again in the pink cone phase, and the last, most important treatment is carried out after the petals fall. In the summer, crops from this disease are treated with a break of 15-20 days. If the season turned out to be rainy, due to which the level of humidity regularly rises, then the plants will have to be sprayed against scab at least 5-6 times.

Prevention

Many gardeners have learned from their experience that it is much easier to prevent the development of scab by regularly carrying out preventive measures than to deal with the disease later.
There are certain agrotechnical methods that are very effective in the fight against scab. Example:

• It is necessary to timely clean the surface of the soil under trees and shrubs from fallen leaves, as well as dig up the soil in the trunk circles.
• In order to timely notice the beginning of the development of the disease, frequent and regular inspections of trees should be carried out during the growing season. Fruits and leaves that look suspicious are immediately cut off and destroyed.
• Do not forget to thin the crown of shrubs and trees every year, because when they are thickened, the development of scab occurs very quickly.
• It is recommended to feed the plants with leaves, using fertilizers based on phosphorus, potassium carbonate and silicon.
• When November ends in autumn, bushes, trees, and even the surface of the soil under them are sprayed with a solution of urea (7%), ammonium nitrate (10%) or nitroamofoska (10%). Also, MicoCell (25 g/10 l of water) or Sporomax T (20-30 g/10 l of water) are used to destroy fallen leaves and combat soil pathogens. When spraying plants with these preparations, the air temperature should not be lower than 4 degrees.

Thanks to this treatment, not only will most pathogenic microbes and pests be destroyed, but also the bushes and trees will receive additional nutrition.
For home plots, in order to reduce the negative effects of chemical fungicides, to prevent the development of scab and other diseases, the use of biological preparations Sporomax B, Sporomax T. The combination of Sporomax B (10-20 g/10 l of water) + Microstim PS ( 75-100 ml/10 l of water). It carries out such spraying from the beginning of bud break and throughout the growing season.

Scabies on trees

Apple scab

Apple trees are most often affected by scab. Initially, leaf scab develops: olive-colored spots are formed on the front surface of the affected leaf plates, which are covered by a velvety plaque containing fungal spores. With the development of the disease, the leaves begin to fall. Later, damage to the fruits is observed: spots of brown color with a border of a lighter shade are formed on their surface, on which a velvety coating appears. This plaque disappears over time, and the cortical tissue can be found under it. Then there is an increase and cracking of such cork spots, and often they are connected to each other. The shape of the affected fruits becomes irregular and ugly, and they themselves are very poorly stored.

To cure a sick apple tree, agrotechnical measures should be combined with spraying trees with special chemical fungicides. Diseased stems detected on the plant must be cut out, and it is also ensured that the stem circle is always clean, for this, timely remove and destroy fallen fruits, leaves, and remove weeds. Mandatory digging of the trunk circle is carried out in autumn. Thinning and sanitary pruning of trees is carried out at the beginning of spring.

In order to prevent scab, apple trees are sprayed shortly before the movement of juice begins, for this purpose a solution of Nitrafen emulsion (20 grams per 1 liter of water) or DNOK (10 grams per 1 liter of water) is used. The first spraying of an apple tree with a medicinal purpose is carried out in the phase of a green cone with a solution of Bordeaux mixture (1%), and the second time the tree is treated in the phase of a pink bud, for this use Skor's solution (2 milligrams per bucket of water). If you did not have time to spray the plant on the dormant buds with Nitrafen or DNOK in a timely manner, then it is recommended to carry out "blue" spraying with Bordeaux mixture solution (3-4%) in the phase of the green cone, and if desired, the treatment in the phase of the pink bud in this case may not be carried out. Then the apple trees are sprayed from scab regularly with a break of 15-20 days, for this purpose such agents as Tsineb or Captan in the form of an emulsion (5 g per 1 liter of water), Hom (4 g per 1 liter of water) and colloidal sulfur are alternately used suspension (10 g per 1 l of water) or Microstim PS (75 ml/10 l of water). When at least 30 days remain before harvesting, it is necessary to stop all spraying with chemical pesticides. In years when there is a mass damage to apple trees by scab, after harvesting the plants are sprayed 1 more time, using Tsineba solution (0.5%) or Bordeaux mixture (1%).

Pear scab

Symptoms of pear scab are almost the same as those of apple tree (see above). However, in pears, spots on the leaves are formed on the lower surface, and in addition to fruits and leaf plates, young shoots are also affected by this disease. The causative agent of scab overwinters on tree branches, as well as on fallen leaves under the plant.

15-20 days after the opening of the buds, the first symptoms of scab appear. If the tree was affected by the disease early (in the spring or in the first summer weeks), then the spots that appeared on the leaves and fruits will be large. And if the tree became infected with scab later, then the spots will be smaller. The later appearance of scab is observed in the case when there is wet weather before harvesting. In this case, the spots that appeared are very small and are almost invisible, but they will definitely appear during storage. These fruits are called "storage pear". Many very small bubbles appear on the bark of diseased stems, while their surface becomes rough and begins to peel.

The most susceptible to scab are such pear varieties as: Forest Beauty, Mlievsky Bergamot, Sapezhanka, and Winter Bere Ligel. Relatively resistant to this disease are the following varieties: Bere Hardy, Bere Ardanpon, Bere Bosch, Mliivska Ossinya, Lyubimytsia Klappa, Vrodlyva, Vyzhnytsia, Etude, Trembita, Zolotovoritska, Stryiski, etc.

In order to cure trees affected by scab, it is necessary to clean the surface of the soil under them from fallen leaves and fruits in a timely manner. Mandatory pruning is carried out in the spring to thin out the crown and remove all diseased and withered branches, which are destroyed by fire.

In autumn, the area is cleared of fallen leaves and fruits, which are also burned. In order to destroy pathogens that winter in the soil near the trunk circle and in the bark of the plant, in deep autumn and at the beginning of the spring period, the ground under the pear is dug up, and the tree and the soil under it are sprayed with a solution of Nitrafen (3%) or DNOK (1%). To process one hundred,

2 buckets of solution are needed. In the spring, the first treatment, called "blue" spraying, of pears with scab is carried out in the green cone phase, for this purpose a solution of Bordeaux mixture (3%) is used. Then the plant is sprayed in the phase of the pink bud and after flowering, for this they take a solution of the drug Skor (2 grams per bucket of water). When 1.5-2 weeks have passed from the moment the leaves become rough and again after 20 days, pears are sprayed with a solution of one of the following agents: Khom, Kaptan, Skor, Tsineb, colloidal sulfur and other drugs with a similar effect.

Peach and apricot

Stone crops are affected by scab less often than seed crops, but this disease is still dangerous for them. With high humidity against the background of moderate air temperature, the probability of damage to apricot and peach by scab increases. When the air temperature rises to 30 degrees, the disease begins to develop much more slowly.

The first symptoms of scab on apricot and peach fruits are specks with an indistinct outline of greenish-brown color. Over time, there is a darkening and growth of spots, a velvet coating of black or olive color is formed on their surface, and their borders become clearer. If the plant is very badly affected, then the spots connect with each other and form a crust. Fruit growth slows down, ulcers and cracks form on their surface, through which pathogens of fruit rot can penetrate. Most often, the affected fruits fly around. In sick stems, there is a delay in development, but in the lower surface of the affected leaves, many vague spots of green or brown color are formed. Apricot varieties such as: Red-cheeked, Shalah and the entire "pineapple" group are most susceptible to scab.

To spray trees on dormant buds, for the purpose of prevention, a solution of Bordeaux mixture (3-4%) or another agent containing copper is used. The plant is sprayed directly from the scab in the first decade of June, using Skor, Horus or Kaptan (strictly follow the instructions on the package). After 15 days, repeated spraying is carried out. Later treatments will not give the expected effect, but after all the leaves fall from the apricot in autumn, it can be sprayed with a solution of Bordeaux mixture (1%). Fungicides containing copper are the most effective against scab on apricots. And in order to protect the plant from this disease, one should not forget about the rules of agricultural technology of this crop.

Damage to plum scab occurs under the same conditions that in the case of other stone crops, the symptoms of the disease are also revealed. In this regard, it is necessary to treat a plum in the same way as an apricot:

• the plant is treated for the first time in the spring on dormant buds ("blue spraying);
• in the first decade of June, treatment with a solution of Horus or Skor is carried out, after 15 days, repeated spraying is required;
• when all the leaves fall from the plant in autumn, it is treated with Bordeaux mixture (1%) or Sporomax T (20-30 g/10 l of water).

Cherry

Like other stone crops, cherry is relatively rarely affected by scab. But if the plant is affected by this disease, it is not the scab itself that will harm it the most, but the causative agents of various rots, which easily penetrate into the cracks formed due to the disease in the fruits. In this regard, in order not to lose the harvest and protect cherries from disease, preventive treatments should not be neglected, which begin to be carried out in early spring with the same means and according to the same principle as in the case of apricot.

Fruit trees

Citrus crops can also be affected by scab. Apricots, quinces and cherries can also get scabies, and you can deal with the disease in the same ways and in the same time frame as in the case of pears, apples and apricots. Do not forget about preventive measures, which are practically the same for all garden trees.

Treatment of shrubs from scab

Gooseberry

Gooseberries are also susceptible to scab. However, gardeners often confuse the symptoms of this disease on such a shrub with signs of powdery mildew, but these are different diseases. That is why, before starting to treat the bush, try to compare all the signs of the disease to be absolutely sure that it is scabies.

So that the plant does not get scabies, do not forget to regularly carry out preventive spring treatment on buds that are not yet swollen. For this procedure, a solution of urea (7%) is used, and note that after spraying, both branches and buds, as well as the surface of the soil under the plant, should be well moistened with the agent. When November ends in the fall, the ground near the gooseberry is cleaned of dead leaves and the trunk circle is dug up and sprayed again with a urea solution.

If the bush was still affected by scab, then it is sprayed on the swollen buds with a mixture of such products as Horus, Strobi, Tiovit Jet, etc. or Bordeaux mixture solution (2-3%). After 30 days, repeated spraying with the same drugs is carried out.

Currant

In comparison with gooseberry currant is affected by scab much less often. However, experts do not advise taking risks and recommend taking all necessary preventive measures. Since gooseberry and currant are related crops, the same methods and drugs are used to fight scab. But even in this case, before starting processing, you should make sure that the plant is definitely sick with scab, and not powdery mildew.

Scabies on potatoes

Potatoes can also be affected by scab, as can fruit trees. In this case, the surface of the tubers is most often affected, due to which they become ugly, and the seed quality and taste of such potatoes deteriorate greatly. Therefore, affected root crops cannot be stored for a long time. If the potato is very badly affected, it cannot be used for food.

It is not recommended to use the areas on which bushes affected by scab grew for growing potatoes for 4 or 5 years (at least). This culture can be affected by the following types of scab: common, bumpy (oosporosis), black (rhizoctoniosis), silver and powdery mildew.

Learn more about each type:

• Common scab. On the surface of the tubers, small, not very deep, irregularly shaped ulcers are formed. Over time, the specks increase, they connect with each other, and a corky formation appears on their surface. If you dig up a diseased potato, you will see a cobweb on its surface, but it will disappear as soon as the tubers dry out.
• Powdery scab. It occurs if the causative agents of the disease get into the roots, tubers and stolons due to mechanical damage or holes. On the surface of the roots, the formation of galls is observed, which are irregularly shaped white growths that become darker as the disease progresses. And many warty pustules appear on the tuber, which over time become ulcers with a brown, oozing mass. During storage, diseased potatoes are often affected by dry rot or late blight.
• Silver scab. You can understand that potatoes are sick during the process of collecting tubers or during storage. Hardly visible matte spots of various sizes and shapes of a brown shade are formed on diseased tubers. The disease begins to actively develop closer to spring. At this time, the affected tissue on the tuber takes on a metallic sheen and looks slightly depressed inward. If the potato is very sick, it loses a lot of moisture, due to which the skin becomes wrinkled.
• Tuberous scab (oosporosis). Damage to the tubers occurs in the ground, during their active growth, but you can understand that they are sick only in the storage. Round pustules appear on the potatoes, which are colored in the same shade as the skin. These pustules are convex, depressed or flat. Over time, they increase in size and form areas that are outwardly similar to late blight lesions, but in this case there is no rot under the skin.
• Black scab (rhizoctoniosis). This type of scab affecting potatoes is the most dangerous. Because of it, the gardener can lose up to 20 percent of the crop. Due to this disease, the tubers die, the apical leaf plates twist, mold appears on the basal parts of the bush. And because of it, the stems of the bush can rot and die.

In order to prevent potatoes from being affected by this disease, it is necessary to plant only completely healthy, high-quality planting material. Immediately before planting, do not forget to treat the tubers with a solution of Sporomax™ B and Sporomax™ T. Adding manganese, boron and copper to the soil can help reduce the probability of plant damage by scab. It is also very important not to forget the rules of crop rotation in order to prevent such a dangerous disease. Yes, it is recommended to alternately grow potatoes and plants belonging to the leguminous family on the site. And in that case, if you cannot plant potatoes in a new area every year, then be sure to refuse to apply fresh manure to the soil.

Alkaline soil on the site is recommended to be acidified with a solution of ammonium sulfate (2 tablespoons per bucket of water). The soil on the site is poured with such a solution during the flowering period of the bushes, and 1 liter of the mixture is used per plant. When there are about 15 days left before harvesting, it is recommended to mow the tops, thanks to which the skin on the tubers will become stronger. During the formation of buds, spray the bushes with a solution of Zircon, this will not only stop the development of scab, but also help increase the yield. After 15-20 days, the plants are treated with Sporomax™ B and Sporomax™ T (1 sachet per 5 liters of water), thanks to which the degree of tuber damage by scab will decrease.

Experts advise to choose for cultivation those varieties that are most resistant to scab, for example: Aspia, Skoroplidny, Alpha, Lady Rosetta, Mentor, Nikolay, Prevalent, Patrones, Element, Polyana, Yavir, Vesta, Dara, Rakurs, Tiras, Riv' Era, Lyubimets, Reserve, Jerelo, Visnyk, Varmas, Ramenskyi, Vilnia, Vyatka, Zhukovsky early, Bezhytskyi, etc.
To cure a plant affected by scab, fungicides are useddrugs belonging to the 3-4 class of danger, because they are not able to form stable compounds, penetrate through the skin or accumulate inside the fruit. Which means to choose in this or that case depends on various factors and the personal preference of the summer resident. However, the disease is most often combated with such drugs as: Horus, Skor, Rayok, Strobi, Abiga-Peak, Phytoflavin, Bordeaux liquid and copper sulfate.