Types of potato nematodes in Russia

Despite the fact that the potato is an unpretentious plant, it is one of the most affected by diseases and pests of crops. All summer residents know about the Colorado potato beetle, which can be seen with the naked eye. However, large losses in potato yield can be caused by a microscopic pest - potato nematode. This is a round worm, the size of which does not exceed 1 mm.

All potato nematodes are highly fertile and subsist on the host plant. In Russia, there are several types of this pest.

Golden and pale

These two species are potato cyst nematodes and cause disease globoderosis... Malicious pests, they are objects of internal and external quarantine in the Russian Federation.

The pest lives in the ground, spreads through the soil, containers and tools, tubers with earth residues, melt water, etc. It is stored in the soil up to 10 years.

The golden potato nematode is found all over the world, including in Russia, especially in its central part and Siberia. Pale nematode is common in Europe, Latin America, Canada, cases of appearance in Russia are not registered.

The life cycle of both types of parasite is the same and continues. about 40-60 days... The pest hibernates in the form of larvae and eggs in strong cysts.

In the spring, when young potatoes emerge, the eggs develop into larvae and penetrate the roots of the plant. The maximum range of their movement in the soil is 1 meter. In the roots, they lose mobility and develop until they turn into males and females. The optimum temperature for life is 15-20 degrees.

The males enter the soil completely, and the females gradually grow, thicken and tear the roots, remaining partially inside the plant. After fertilization, males die, and females begin to lay eggs inside their own bodies. Fertility of one individual - from 200 to 1000.

When the eggs are ripe, the female's body dies off, its outer shell becomes hard and turns brown. This is how a cyst appears - a dead female with eggs inside. When harvesting potatoes, the cysts crumble, fall into the soil and winter there.

Golden nematode is called because during its life cycle her female changes color: first it is white, then cream and finally golden yellow. In females of the pale nematode, the white-cream color remains dominant.

Potato stem nematode

The female can lay eggs at a temperature from 5 to 37 degrees... The life cycle takes 20-45 days... Pests hibernate in the egg stage, while tolerating soil freezing well.

Early varieties are especially harmful. Infection occurs more often from the mother tuber than through the soil. From the ground, the nematode penetrates the tuber while it is forming. The pest infestation is especially strong in rainy years.

North Gaul

The pest parasitizes various plants, including potatoes, which causes tuberous tuber... Growths (galls) appear on the roots of an infected plant, as a result of which the internal vascular vessels become clogged and the plant begins to experience a lack of nutrients. In cold winters, it dies in the soil.

There is a danger that in the coming years other species of root-knot nematode - Colombian (Meloidogyne chitwoodi) and nematode Meloidogyne fallax - may appear in Russia. These pests are already found in European countries.

Signs of defeat

Symptoms of aureus infection

The defeat always begins as focal.

Signs:

• young plants are stunted;
• the stems are frail, the leaves are small;
• observed premature yellowing of foliage upwards;
• roots are crushed, in case of severe damage, additional roots may form, since the plant is experiencing an acute lack of nutrition.

7 weeks after planting, pest cysts can be seen on the roots, first white, then bright yellow and eventually red-brown.

Tubers always small and few... Symptoms are especially pronounced if potatoes grow on poor, poorly fertilized soils.

Stalk infestation symptoms

Usually there are no external manifestations of the pest. In case of severe defeat leaves turn pale, become wavy at the edges... The internodes are shortened, the stems become thicker and bushy.

On tubers under the skin appear small white spots with a hole in the center... The pulp gradually becomes soft in the affected area. During storage, dark leaden spots form on the tubers. Over time, they grow and crack, from which the tuber dries quickly.

Prevention and control measures

Agrotechnological

The main method of pest control is use of nematode-resistant varieties and avoidance of monoculture.

Since the parasite lives in the soil, the annual planting of potatoes in one place contributes to the rapid spread of the pest. To prevent this from happening, you should alternate potatoes with the cultivation of other crops, that is, observe 4-5 year crop rotation.

The best predecessors will be plants that are not affected by this pest:

• cereals (including corn);
• legumes;
• legume-cereal mixtures;
• siderates (lupine, mustard, rapeseed);
• pure steam.

The essence of the method: in the fall, after harvesting and thoroughly cleaning the field from plant residues, they bring manure (160-240 t / ha), dug up and snatch with a thick layer of mulch. For example, you can use chopped straw, hay, or grass cuttings. With a layer of mulch, the field is left for the winter.

At the beginning of summer, all sprouted potatoes that were missed during the autumn harvest are removed from the site. The shelter is not removed. During dry season water the field 1-2 times... After the next wintering, the remnants of the mulch layer are removed, a nematode-resistant potato variety is planted in the field, and grown for at least two years in a row.

The effectiveness of the method: under favorable weather conditions (warm winter, a lot of precipitation in summer), the destruction of the pest can reach 98%. Nematode larvae will die from natural enemies: bacteria, ticks, predatory fungi.

It is impossible to constantly plant only nematode-resistant potato varieties. This can lead to the pest becoming more hardy. A common variety is planted every 3-4 years.

Chemical

Strong chemical preparations can be ineffective, since the cysts in the soil are protected by a hard shell, and after the larvae are introduced into the plant, the use of pesticides can harm the future harvest.

Some chemical treatments:

• A month before planting, in those places where the infected plants grew last year, they bring urea and watered with an infusion of potato sprouts: the larvae wake up, go into the soil and die.
• When planting potatoes, add ash, poultry manure powder, rotted manure... All this is sprinkled with earth and the tuber is planted.
• After planting, the soil is watered liquid chicken droppingsdiluted with water 1:20. Watering rate 4-10 liters per 1m2. Such a solution is detrimental to the larvae of the pest.

Folk ways

Popular ways to deal with a pest include the following tricks:

• Fertilizing the soil with manure... In fertile soil, microorganisms are well developed - the natural enemies of the pest.
• Sowing rye after harvesting potatoes... According to the observations of gardeners, rye is better than other cereals, it helps to reduce the number of nematodes on the site.
• Use of protective plants... Experienced summer residents plant small marigolds, calendula and rudbeckia next to potatoes, the smell and root secretions of which the parasites do not like.

Such plants need remove from the site and burn... After working with an infected plant, you need to rinse well, and it is better to disinfect containers, tools and shoes that have come into contact with the ground.

In general, the correct observance of crop rotation, careful care of potatoes, timely application of fertilizers to the soil help prevent the spread of the parasite on the site. After all, the best way to combat any plant disease is prevention.