Is it Necessary to Tolerate Scab in the Garden

Scab-a disease that does not include rot. It is a predisposing factor that creates favorable conditions for pathogens of dry and wet rot.

Just seems that a scab is a disease almost is not harmful to the crop. In the quiet years is really so, because the tubers are stored well in the cellar. Another thing-years with excess moisture and a suitable temperature regime: then the scab can bring very significant harm.

Black scab

Particularly raging if the spring is rainy and cold. The gardener may lose a quarter of the expected yield. There are several forms in which it manifests itself. Possible decay buds and shoots, dieback of roots and stolons, tuber necrosis…

Signs of black scab of potatoes

If the skin of the tuber stuck little lumps of earth, but they cannot be shaken off or brushed off with a gloved hand, they can not be erased, but you can knock over with a fingernail or scrape off along with a portion of skin on which they sit, is a Black scab.

If the weather is warm, the sprouts from diseased tubers may seem from the soil, even grow into a Bush, but will be visible encircling the rim, twisted along the veins of the upper leaves, sometimes with anthocyanin color. In the axils of shoots may appear small green air tubers. The bushes will be small. If the weather becomes warm, with high humidity, then the lower parts of the shoots will appear white plaque, similar to the film.

Is it Necessary to Tolerate Scab in the Garden
The photos of the collage show the manifestations of black scab on the tables, tubers, upper leaves

The time of tying the tubers (in hot weather — the time of flowering) — the period of appearance of the mesh on the skin, with the growth of the tubers, the skin in these places bursts.

What harm does a black scab

There is almost no harm to the tuber, because the formations are superficial. The fungus becomes active in spring, when planting in cold wet ground, in the same cold and wet weather. The mycelium gets to the sprouts, they formed a depressed dark spots, which gradually grow, forming around the germ ring. The plant is difficult to pull out of the soil.

Affected sprouts die without even appearing from the soil. For the gardener it can look like a simple bald spot in a row. If the tubers with black specks when planting was a lot, then part of the bushes just will not appear. Therefore, do not plant potatoes in cold soil, and even deep to bury the tubers. Apparently, it is not for nothing that our ancestors believed that the best time for planting potatoes is determined by the temperature of the soil — bare feet should be comfortable. This mushroom affects beets, pumpkins, tomatoes.

Is it possible to reduce the damage

In autumn and spring, etch seed potatoes, plant only healthy sprouted tubers.

Common scab

Usually gardeners and gardeners believe that this potato disease does not do much harm. Perhaps the most unpleasant manifestation of it is the ugly skin of tubers. Well, it’s not scary, because four beds are grown for your table, not for sale. However, this is not quite right.

The damage can be very impressive, judge for yourself: in different regions, scab ordinary can affect more than half of all tubers, germination can decrease by 15%, lost up to a third of the crop, and the tubers themselves become tasteless, because the starch (it depends on the friability) and the protein in them less. The causative agents of scab need to “eat”, and starch and protein — very high quality food.

Signs of common scab of potato

Accomplices of common scab, pathogens of dry and wet rot, penetrate the affected tubers through the “wounds”. Different wet spots, ulcers that peel-it’s not a scab.

What harm does an ordinary scab bring

Common scab — underground resident, it is parasitic only on the stolons, and tubers. Pathogens-radiant mushrooms actinomycetes, penetrate only into young tubers during their formation, when tiny tears of skin tissues are possible, when lentils are actively working, because the nodules are actively growing. At first, the development is invisible to the gardener, if he digs a hole, it is unlikely that he will see, because sometimes only by the end of the second month, the brown spots on the skin become visible. The settlement of tubers by pathogens can be stretched for up to thirty days.

Common scab forms

Scab — a disease of the surface. It can be in four forms that differ in appearance:

  • convex scab: first, the skin of the tubers appear in the recess in the form of a cone, then they are lifted, take the form of small warts or scabs up to 2 mm;
  • flat scab: the skin hardens, changes color from light brown to dark, on the skin formed ulcers in the scabs;

Is it Necessary to Tolerate Scab in the Garden
This scab so disfigures the surface of the tuber, opens passages for pathogens of fungal diseases

  • netted scab: across the solid rough peel scab from the grooves going in different directions;
  • pit (deep) scab: ulcers are formed with a depth of 5 mm, their diameter can be very large (in comparison with the size of the tuber), the skin around them is broken. The inside of the ulcer is loose and soft.

Is it possible to reduce the damage

Common scab like alkaline soil, so do not overdo it with the deoxidation. If you choose a plot for potatoes, then three or four years before growing it is not necessary to make lime for deoxidizing, it is better to do it for predecessors. With pathogens of common scab, soil bacteria fight well. But the soil should be wet, not dry, when the potatoes tie the tubers, otherwise the protection will not work. Ordinary scab like warm soil, with a low content of humus (humus is able to restrain its onslaught). It develops only in the field, and calms down in storage.

The seed material is almost not stored in the cellar from the tuber to the tubers is not transmitted. More susceptible to scab common:

  • tubers with thin skin;
  • varieties with red skin;
  • early varieties of potatoes.

Powdery scab

You can lose more than half of the possible crop. Against the background of scab (through sores on the surface), the tubers can develop blackleg. For the development of the disease requires increased soil moisture, only under this condition the pathogens are able to penetrate into the cells. A scab is a parasite on all the underground organs from being affected plants may die.

Signs of powdery scab potato

A month after planting, tuber small brown spots, and brown streaks. In place of spots appear convex pustules, similar in structure to the jelly, their diameter is not more than 4 mm, they grow to a diameter of 1 cm, and then darken and dry up.

Is it Necessary to Tolerate Scab in the Garden
Damage of potato tubers with powdery scab

If the affected stolons, stems, roots, can be seen white growths — it’s like cancer.

Is it possible to reduce the damage

To treat the tubers for planting. Plant in agronomic terms, in warm land, preferably not heavy and not acidic. If the cows were fed sick tubers, the manure will spores of the fungus, this is another source of infection.

Silver scab

There are no shoots, because the eyes of the tubers are dying. Or they are changed: weak, similar to a thread, they are less, than happens usually at healthy tubers, and length is shorter. These potato bushes are stunted by their neighbors. Tubers are ugly or do not grow the size that guarantees the description of the variety, because the stolons are affected.

Is it Necessary to Tolerate Scab in the Garden
This is how the silver scab looks on the tuber with white skin

Signs of a silver scab of potato

All underground organs of the plant are sick, especially tubers, which are infected during the entire period of cultivation. Autumn disease is a little noticeable: at this time, to see the characteristic silver glitter scab — spots are light brown, try, try to understand that there is hidden on the yellow peel under the soil residues. You can determine visually during storage-about a month and a half after the bookmark. All the” beauty ” of the tubers are acquired by the spring: then there is a metallic silvery Shine, especially noticeable if the potatoes are simply wet with water.

Is it possible to reduce the damage

Mycelium lives only in the cells of the skin, which changes its color from light brown to dark brown. Because you need a double etching: in the autumn, before laying seed tubers for storage, and in the spring, before planting. Cutting the tops before harvesting allows the tubers to create a dense peel, which makes them resistant to the disease. Grow rye as a precursor of potatoes, do not spare humus or other organic matter for fertilizer, it increases the number of microorganisms in the soil and increases its acidity.

Lumpy scab

The pathogen harms the eyes of seed potatoes, reduces the content of starch, protein and vitamin C. Weakened tubers are easily damaged by black and silver scab, rot. The disease can be determined after three or four months of storage of tubers. Because of damage to the eyes, germination is reduced, and some sprouts that have risen are already affected by the disease.

Signs of lumpy scab potatoes

Infection occurs in the soil during the formation of tubers. But it can only appear during storage, about two or even four months after cleaning. On the surface of the tubers near the eyes and lenticels are formed closed skin bumps with a diameter of about 5 mm. Around them pressed in, the ring formed by cells. Depending on the variety of potatoes, tubercles can be of different shapes, single or multiple, merging into one structure.

Is it Necessary to Tolerate Scab in the Garden
It looks like lumpy scab on potato tubers

Later, they turn into pustules, the edges of which are pressed into the flesh of the tuber, and the Central part is raised above the surface. Outside pustules dark brown, and if the tuber to wet with water, inside their color will change to gray-purple, because there-rot.

Is it possible to reduce the damage

Observe crop rotation, dry seed tubers before laying on storage. Ventilate the cellar to avoid being too wet.

And you fight scab of potatoes? Or do you allow her to freely manage your garden?

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