Despite the fact that potatoes are an unpretentious plant, it is one of the most affected by diseases and pests of crops. All the summer residents know about the Colorado beetle, which can be seen with the naked eye. However, large losses of potato yield can be caused by a microscopic pest - a potato nematode. This is a round worm, the size of which does not exceed 1 mm.
All potato nematodes are highly prolific and exist, feeding on the host plant. In Russia there are several species of this pest..
Table of contents
- Types of potato nematode in Russia
- Golden and pale
- Stem nematode of potato
- Northern Gallic
- Signs of defeat
- Symptoms of infection with golden
- Symptoms of infection with cauline
- Prevention and control measures
- Folk ways
Types of potato nematode in Russia
Golden and pale
These two species refer to potato cyst-forming nematodes and cause diseaseglobodeosis. Malignant pests, they are objects of internal and external quarantine in the Russian Federation.
The pest lives in the ground, spreads through the soil, tare and tools, tubers with the remains of the earth, thawed waters, etc. Preserved in soilup 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 continuesabout 40-60 days. Pest wintersin the form of larvae and eggs in strong cysts.
In the spring, when the young potato rises, larvae develop from the eggs and penetrate into the roots of the plant. The maximum range of their movement in the soil is 1 meter. In the roots they lose their mobility and develop until they turn into males and females. The optimum temperature for life is 15-20 degrees.
The males come out into the soil completely, and the females gradually grow, thicken and tear the roots, remaining partially inside the plant. After fertilization, males die, and females start laying eggs inside their own bodies. Fecundity of one individual -from 200 to 1000.
When the eggs ripen, the female body dies, its outer shell becomes hard and turns brown. So there is a cyst - a dead female with eggs inside. When harvesting potatoes, cysts are crumbling, falling into the soil and hibernating there.
The golden nematode is called because during the life cycleher female changes color: first it is white, then creamy and, finally, golden yellow. In females of pale nematodes, the white-cream color remains dominant.
Stem nematode of potato
A female can lay eggs at a temperature offrom 5 to 37 degrees. The life cycle is20-45 days. Pests in the egg stage hibernate, well tolerating the freezing of the soil.
Especially great harm is caused to early varieties. Infection occurs more often from the mother tuber than through the soil. From the ground, the nematode penetrates into the tuber, while it forms. Particularly severe pest damage in rainy years.
The pest is parasitic on different plants, including potatoes, whichcauses tuberculation tubers. On the roots of the infected plant, build-ups (galls) appear, as a result of which the internal conducting vessels are clogged and the plant begins to lack nutrients. In cold winters perishes in the soil.
There is a danger that in the coming years other species of Gallic Nematode may appear in Russia - the Colombian (Meloidogyne chitwoodi) and the Meloidogyne fallax nematode. These pests are already found in European countries..
Signs of defeat
Symptoms of infection with golden
The defeat always begins as a focal.
- young plants lag behind in growth;
- stems are formed frail, leaves are small;
- observedpremature yellowing of leavesdown up;
- roots are soaked, with severe damage, additional roots can be formed, since the plant suffers from a severe shortage of food.
Seven weeks after planting, the roots of the pest can be seen on the roots, first white, then bright yellow and eventually red-brown.
Tubers alwayssmall and few. Symptoms are especially pronounced if the potatoes grow on poor, low-fertilized soils.
Symptoms of infection with cauline
Usually there are no external manifestations of the pest. In case of severe injuryleaves pale, become wavy along the edges. The internodes shorten, the stems become thicker and bushy..
On the tubers under the skin appearsmall white spots with a hole in the center. The flesh gradually becomes soft in the affected area. During storage, dark spots with a lead tint are formed on the tubers. Over time, they increase and crack, from which the tuber quickly dries up.
Prevention and control measures
The main method of pest control -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, alternate potatoes with the cultivation of other crops, that is, observe4-5 summer rotation.
The best predecessors will be plants that are not affected by this pest:
- cereals (including corn);
- legume-cereal mixtures;
- siderates (lupine, mustard, rapeseed);
- pure steam.
The essence of the method: in autumn, after harvesting and thorough cleaning of the field from plant residues to the site,manure(160-240 t / ha), dig through and snatch a thick layer of mulch. For example, you can use chopped straw, hay or sloping grass. With a layer of mulch the field is left for the winter.
At the beginning of summer, all the potatoes that have risen are removed from the site, which they missed during the autumn harvest. Shelter is not removed. During the dry seasonwater the field 1-2 times. After the next wintering, the remains of the mulching layer are removed, the potato variety resistant to the nematode is planted on the field and grown for at least two consecutive years.
Effectiveness of the method: under favorable weather conditions (warm winter, plenty of precipitation in summer), pest extermination can reach 98%. Nematode larvae will die from natural enemies: bacteria, ticks, predatory fungi.
You can not always plant only nematode-resistant varieties of potatoes. This can lead to the fact that the pest will become more hardy. Every 3-4 years, plant a normal variety.
Strongly acting chemical preparations can be ineffective, since in the soil the cysts are protected by a solid shell, and after the introduction of larvae into the plant, the use of pesticides can harm the future crop.
Some chemical ways of fighting:
- A month before planting in those places where the infected plants grew last year, they makeureaand watered with infusion of potato sprouts: larvae wake up, exit into the soil and perish.
- When potatoes are planted in a hole,ash, bird droppings, overgrown manure. All this is sprinkled with earth and a tuber is planted.
- After planting the soil is wateredliquid chicken droppings, diluted with water: 0. The rate of irrigation is 4-10 liters per 1m2. Such a solution is disastrous for pest larvae.
To folk ways to fight a pest, you can include the following tricks:
- Manure fertilization with manure. In fertile soil, microorganisms are well developed - natural enemies of the pest.
- Sowing rye after harvesting potatoes. According to observations of gardeners, rye is better than other cereals, helping to reduce the number of nematodes in the area.
- Use of plant defenders. Experienced summer people plant next to the potatoes, small marigolds, marigolds and rudbeckies, the smell and root offspring of which do not like parasites.
Such plants needremove from the site and burn. After working with the infected plant, it is necessary to rinse well, but it is better to disinfect containers, tools and shoes that come into contact with the ground.
In general, proper observance of crop rotation, careful care of potatoes, timely introduction of soil fertilizers in the soil helps prevent the spread of the parasite on the site. After all, the best way to combat any plant diseases is prevention..