Golden potato nematode

Globodera potato and its causative agent Globodera rostochiensis

In recent years, the population increasingly appeals to us with complaints about poor plant growth and development, as well as unsatisfactory storage harvest of potato tubers... One of the reasons for this is the infection of potatoes with globoderosis. Every year, in the spring and autumn, the specialists of our department carry out control quarantine phytosanitary examinations of household plots, examining the contamination of the soil with dangerous quarantine pests and weeds. This is necessary in order to prevent their emergence and widespread distribution in private households.

Globoderosis (potato nematode infection) is caused by golden and pale nematodes. Both types of nematodes are quarantine objects. On the territory of Russia and Belarus, only the golden potato nematode is registered. At present, this parasite is widespread mainly in household plots, where potatoes have been cultivated permanently for many years. Globaderosis is a type of roundworm. They hibernate in the soil, in the spring the larvae are born, penetrating into the roots of potato seedlings, and later into young tubers. In addition to potatoes, the nematode damages tomatoand also feeds on weeds from the nightshade family.

Infected plants have fewer stems that become long and thin, stunted, and their lower leaves turn yellow and wither. Tubers are not formed or only one or two tubers are formed. The roots of plants are highly branched, they are brown in color, cysts in the form of golden brown balls are visible on them. From the point of view of phytosanitary standards, potatoes grown in areas infected with golden potato nematode are absolutely safe for people and can be used for food purposes.

The potato nematode brings the greatest harm on personal plots with permanent cultivation of this crop in the same place. It greatly reduces the yield of tubers. The source of infection is contaminated soil and tubers, tools (shovel, plow, etc.), with which the infected areas are processed.

How to deal with a nematode? First of all, you should never plant material of unknown origin in a clean, uninfected area (including not only potato tubers, but also tubers of other crops, bulbs, rhizomes, seedlings, cuttings, etc.). It is necessary to purchase seed only in specialized stores that sell products with the appropriate documents guaranteeing the absence of nematodes and other dangerous quarantine objects.

Foci of nematode spread in the first place quenched by crop rotation... To prevent the spread of the nematode, you need to plant the potatoes in their original place no earlier than 3-4 years later. The methods of control also include the cultivation of special nematode-resistant varieties of nightshade, but they can also be grown in the same area for no more than 3-4 years in a row.

Of the resistant varieties, the most common in our region are: Skarb, Sante, Vineta, Arhidea, Zhukovsky early, Zhivitsa. From the garden you need to very carefully remove, and then burn diseased plants and their remains. It is desirable that there is no wild fellow potato - black nightshade - on and around the site. An autumn method of dealing with a nematode is to sow rye, mustard, rapeseed as a follow-up or green manure culture... All these methods together will give the best results in the fight against nematodes. In addition, they are all harmless to the environment, plants and humans.

Valentina Belokoneva,
Deputy Head of the Supervision Department
in the field of plant quarantine and supervision
for the quality and safety of grain
and products of its processing
Rosselkhoznadzor Administration for Kostroma
and Ivanovo regions

The potato nematode is a tiny parasitic worm with a length of 1 mm. It is impossible to notice it without digging a bush, since helminths are located on the roots. Females firmly attach to the underground part of the plant and by autumn form cysts with a protective shell of golden color. The eggs are favorably preserved in peculiar cocoons until spring, and then larvae hatch from them and begin to parasitize on the roots. One cyst contains more than one thousand fertilized eggs.

  1. The pale potato nematode is a widespread species throughout the world. It affects the bush from the roots to the tips of the upper leaves. The diseased plant dries up quickly.
  2. Golden potato nematode, which got its name from the color of the cyst shell. It affects potatoes and tomatoes, feeding on the juice and nutrients of the plant. The bushes turn yellow and die.
  3. Stem nematode. Found when harvesting. The tubers have brownish spots with a metallic sheen, under which rot is hidden.

Regardless of the type of nematode pathogen, the result of infection can be disastrous. A serious fight against the disease should be started in any case. Eating vegetables from the affected bushes does not threaten anything. If a golden potato nematode has settled on the site, the danger to humans lies only in the loss of the crop.

Potato nematode: photo and control measures.

The potato nematode is a quarantine pest, but has been found in 42 countries despite numerous bans. To overcome huge distances without the help of a person is beyond her power. There are a lot of ways of spreading nematodes, from contaminated soil to irrigation water.

The golden nematode develops only on the root system of plants of the Solanaceae family, including potatoes. Living in the roots of potatoes, they strongly oppress the plant or lead to its death. The greatest harm from the nematode is felt in areas of reduced crop rotation; yield losses can reach 80%.

It is impossible to determine whether a site is infected with a potato nematode without analysis. Therefore, the first signs of the presence of a nematode appear directly on the plant. If 45-50 days after planting potatoes, the plants have long and thin stems, yellowed lower leaves, a branched root system of brown color without tubers and golden balls (cysts) are visible on it, then this means a nematode is wielding your site.

Along with declining yields, nematodes contribute to the spread of disease. Stem nematode affects all parts of plants, giving preference to early varieties. Causes a thickening of the stems with a simultaneous shortening of internodes, the formation of small pale green leaves with wavy edges. During storage of the affected tubers, gray spots form on their surface. In the future, the peel is torn at the sites of the lesion. The pulp of the tuber is a rotten brown mass.

The full development cycle of the nematode takes place in the potato root system. When favorable conditions occur, larvae emerge from the cysts. They perfectly feel the root secretions and therefore quickly find the owner. Larvae can be in cysts for up to ten years, without loss of viability. Penetrating into the root system, the larvae lose their mobility and begin to feed on the contents of the cells. Females form eggs and store them in their bodies. The number of eggs depends on the supply of the female with food and fluctuates in the aisles of several hundred. After laying eggs, the females die off, their body hardens and turns brown (cysts). At the end of the growing season, the cysts fall away from the root system and remain in the soil, where they hibernate.

One developmental cycle lasts 2 months. Nematodes are very small worms (0.5 to 2 mm). The mouth area has an organ for piercing the cell wall (spear), through which nematodes extract the contents. As the cells are destroyed, the worm moves through the plant. The female has a more rounded shape, the male is elongated. If you dig up an infected plant in the summer, free the root system from the soil, then you can see female nematodes on it, still white.

Potato nematode control methods are aimed at preventing soil contamination. The whole system includes the following set of activities:

Growing resistant potato varieties, reduces nematode contamination of the soil by up to 90%. On such varieties, the female does not develop and does not give offspring. It is not recommended to cultivate them more than four times in a row in order to avoid the appearance of aggressive forms of the pest.

How to deal with a pest

A potato nematode is defined by the following expression: "It does not burn in fire, does not drown in water." It is very difficult to fight a pest; for this, a whole range of measures is carried out, including agrotechnical techniques and treatment with chemicals. At the same time, no means guarantee absolute effectiveness. Farmers of the EU countries have extensive experience in the fight against nematode, given that it appeared there earlier than in the Russian Federation.

Reference. If your site is in the quarantine zone, if you follow a number of rules, you will be able to grow excellent potatoes. It is important to remember: a product from such a zone is used in cooking, but is not sold in other regions.

The final victory over the potato nematode will take more than one decade of continuous work, but the pest population can be reduced in 1-2 years.

If there are no more than 3-5 cysts per 100 cm3 of soil, there will be no harm to the potatoes. A significant decrease in yield is observed when 10-16 cysts are found per 100 cm3 of land.

Agrotechnical methods

To combat the pest, simple but effective agrotechnical and preventive methods are used:

  1. Crop rotation. Potatoes have not been planted in the same area for several years in a row. Even if a crop is planted in one place no more than once every 3-4 years, a serious increase in the nematode population will occur no earlier than in 40-45 years.
  2. Pest-resistant varieties are planted only 3 years in a row, the next year they choose ordinary planting material. There is another option - to grow only crops with a high degree of protection, but change varieties every 4 years.
  3. In the fall, potato tops and weeds from the infected area are harvested and burned, taking precautions. The working tool is disinfected with a 4% formalin solution.
  4. In autumn and spring, the soil is fertilized with urea. Nitrogen is harmful to potato nematodes. With an insignificant spread of the pest on the site, they dig a hole, throw tops and weeds into it, cover everything with urea (5-6 kg / 1 m3 of green mass), and sprinkle it on top with soil from a "clean" area.
  5. Healthy material is chosen for planting. The tubers are washed and treated with a solution of potassium permanganate (0.5 g / 10 l).
  6. When disembarking, 1 tbsp is added to the holes. l. bird droppings. A solution is prepared from fresh droppings in a ratio of 1:10 and the area is watered.
  7. Rye, beans, peas, marigolds, clover, and mustard are planted next to the beds. The roots of these plants secrete substances that are detrimental to the nematode. If rye is sown on the field in the second decade, up to 90% of the larvae are destroyed, and rotted straw serves as fertilizer in the spring. Nodules containing nitrogen are formed on the roots of legumes. The seeds are added directly to the holes or planted between the rows of potatoes.
  8. Ringed (earthworms) are natural enemies of the nematode. Increasing soil fertility creates favorable conditions for their reproduction.

Golden potato nematode: prevention and control of the pest

Often from gardeners you can hear complaints that no matter how many times they plant potatoes, there is no sense - either the harvest is very small, or there is simply no harvest, and the reason for this is supposedly bad soil.

The composition of the soil affects the quantity and quality of the crop, but the reason may be far from only this. In most cases, in all the "troubles" of gardeners, the culprit is the potato nematode, which infects the roots of plants, as a result of which you can be left without a crop at all.

Golden potato nematode (Globodera rostochiensis) Is a microscopic worm that is one of the most dangerous quarantine pests. She lives on the roots of plants of the nightshade family (on vegetables - potatoes, tomatoes, peppers, etc. and weeds - black nightshade, henbane, etc.). But the potato is the only plant on which this pest can multiply.

The speed at which the nematode multiplies and spreads is very high. But the most dangerous is that the nematode makes plants vulnerable to other diseases, they are prone to the appearance of fungal infections, the signs of which are well known to all gardeners.

The pest usually inflicts especially great harm on personal plots and in collective gardens, where potatoes have been a permanent crop for many years and where practically no pest control is carried out, as well as in fields with a shortened crop rotation, where potatoes are grown permanently or return to their original place after 1–2 years.

The exceptional insidiousness of this underground pest lies in the fact that in the first years after "infection" in the conditions of an amateur garden it is almost impossible to detect it. That is why nematodes are very dangerous, since we do not see our enemy and cannot detect him at the initial stage of soil contamination.

The presence of a nematode in an infected area is really difficult to detect at first. It seems that the plantings are healthy, but that individual potato bushes are oppressed - you don't attach much importance to this. You never know what could be the reason.

The lower leaves of these bushes quickly die off, the rest turn yellow. Flowering is poor, or the formation of tubers is absent altogether, inhibited - they are either too small or absent at all. These bushes can die long before autumn. Namely, these plants signal an impending great disaster.

In the first years after the appearance of the nematode, the affected bushes, if you are careful, are easy to notice in the form of individual small bald patches. But later the spots merge, and almost the entire area is affected. And if you continue to plant potatoes after potatoes on this site, then the nematode will soon leave the sluggish owner without a crop at all, since losses with severe soil contamination can amount to up to half of the crop and much more.

You can find a nematode from mid-July on the roots of potatoes. These are microscopic pests the size of a poppy seed, almost invisible to the naked eye. The body of the female is spherical, slightly smaller, and the male is worm-shaped.

By autumn, females turn into cysts (covered with membranes), the size of a poppy seed of golden brown color, in which eggs and larvae can survive for a long time under unfavorable conditions.

The nematode larvae that appeared in the spring, moving in the soil, find the roots of the potato, penetrate them and develop here until the adult stage, feeding on plant sap and causing their deformation. Moreover, not all larvae emerge from the cysts at the same time, their gradual hatching occurs within 3–6 years.

How does soil contamination with a nematode occur? It occurs by mechanical transfer of the pest, namely:

  • when planting infected tubers
  • when storing infected tubers with healthy ones in conditions of high humidity
  • when using an untreated tool that has come into contact with contaminated soil.
  • when planting tubers in soil where infected potatoes were previously grown.

The first signs of damage to plants by the nematode appear 40–50 days after planting the tubers. Usually such plants have few stems and a poorly developed root system, they form small tubers. These plants begin to stagnate quickly, their upper leaves turn yellow, and the lower ones wither completely. When the temperature rises and the humidity of the air and soil decreases, the plants dry up and die without giving a crop.

If in the summer after flowering in an infected area, remove the plant from the soil and gently shake it off, then on the roots you can see small rounded female nematodes, which at this time have a milky white color.

The source of the nematode spread is infected potato tubers and the soil infected from them near the potato bushes, since during harvesting the cysts fall off the roots and remain in the soil. It is cysts that serve as the main source of infection for all new areas, since they can be transferred on seed potatoes, with tools and even on garden shoes "infected" with nematodes.

The reason for the spread of the nematode in the soil is the incorrect alternation of crops on the site, and most likely its complete absence. The pest is present in almost every garden plot and in every amateur greenhouse, where the same crops are planted from year to year.

Therefore, if crop rotation is not observed on the site, the soil is depleted, and the plants develop slowly, then it's time to plant marigolds in the beds. Nematodes cannot feed on their roots and die. For the same purposes, it is very useful to plant beans, calendula and fragrant sweet clover around the potato field.

It has long been noted that after sowing winter rye, the infected area is also significantly cleared of the nematode. Perhaps rye affects the nematode with the help of root secretions or in another way, only the outbreak of the pest in the area fades away.

Prevention of a dangerous pest is extremely important. The list of such measures is quite extensive.

  • Mandatory observance at the site of the fruit change with the return of plantings of potatoes, tomatoes and other nightshade crops to the same site no earlier than in 3-4 years.
  • In such crop rotations, the best crops that cleanse the soil are legumes (especially fodder lupine), perennial grasses, corn, and only then potatoes of nematode-resistant varieties.
  • Deep autumn digging of the soil is strictly obligatory.
  • The use of organic fertilizers significantly reduces the number of cysts in the soil. In fertilized and mulched soil, the death of cysts occurs from fungi pathogenic for the nematode and predatory arthropods.
  • There are plants whose root secretions are capable of provoking the release of larvae from cysts in the absence of a "host". Plants from the cabbage and aster family are most effective. You can name such plants as tagetes, tansy, white mustard and others.
  • It is necessary to purchase potato seed material only from farms that guarantee its purity from potato nematodes.
  • You can use the crop of potatoes from areas infected with nematodes only for food purposes and for fodder for livestock, but not for seeds.
  • From a site infected with a nematode, inventory, potato tubers, and the topsoil cannot be transferred to other areas.
  • When planting potatoes of unknown origin, it is imperative to rinse the tubers in warm water before planting.
  • It is necessary to grow potato varieties that are relatively resistant to nematode - Alvara, Agria, Anosta, Aspia, Vital, Desnitsa, Diamant, Karatop, Zhukovsky early, Cardinal, Crystal, Ladozhsky, Latona, Liga, Lukyanovsky, Picasso, Prigozhiy-2, Prior, Rikesa, Ryabinushka, Ukoma, Felox, Fregata, Fresco, Hert, etc. Larvae cannot develop in the roots of these varieties.
  • Sick and healthy potato bushes growing nearby must be dug up and buried with a lump of earth in a deep hole dug in advance at the far end of the site, after having thrown them with bleach. Fill the place from under the dug bushes with abundant (I repeat - very abundant) with urea.

And if the presence of a nematode on your site has already reached the size of a natural disaster, then you need to apply a special drug "Bazudin" according to the instructions, which simultaneously effectively acts on another underground "pirate" - wireworm. The effect will be much stronger if your neighbors are engaged in this work at the same time.

You can also get rid of the potato nematode with the help of the Nemabakt predatory nematode, which is usually sold in the Zashchita soil. When planting potatoes, you need to add a little of this soil under each tuber.

Folk remedies for nematodes

The main and, perhaps, the only effective folk remedy for combating the nematode "cheap and cheerful" is spilling the soil with boiling water on the eve of planting.
High temperatures are detrimental to tiny nematodes, and after such a procedure, their number on the site really decreases significantly. You just need to remember that for a real effect, the earth must be saturated with hot water with a temperature of at least 50-55 ° C to a depth of at least 15-20 cm.After that, it can also be covered with polyethylene to cool down more slowly.

Alas, the measure is not fully effective. Although a significant number of nematodes live in the surface layers of the substrate and, as a rule, die during such thermal disinfection, some pests can migrate into deeper layers of the soil and escape.

In addition to the soil, the affected plants themselves can be treated with hot water - this mainly concerns the bulbs and roots affected by the root nematode. They are washed from the ground and then soaked in hot (45-50 ° C) water for 10-30 minutes. Formalin at a concentration of 0.06% can be added to this water as a useful additive.

What does the affected plant look like?

It is very difficult to guess about the existence of parasites due to their small size. Nematodes can only be seen if you look closely. Most often they are found at the moment when the plant can no longer be saved. Harm is caused not only by adults, but also by larvae.

Signs of culture damage by nematodes:

• slowdown in growth and development (internodes are shortened, leaf petioles are thickened)
• weak flowering
• drying of leaves
• curvature and deformation of the stem
• drying out of the kidneys
• excessive branching of the root system
• rotting of small roots, formation of galls and ulcers
• extensive death of the root system.
If the larvae live in the ground, then the seeds may not germinate, seedlings appear later.

Important. Nematodes pierce plant tissues, resulting in a favorable environment for the reproduction of fungi and viruses.

Watch the video: Exploring Nematodes Deepak Haarith. Part 1

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