Description, signs, and treatment of potato nematodes, and how to combat the disease

How to combat the potato nematode in nightshade crops? This devastating parasitic disease destroys up to 80% of the crop. The female parasites form cysts that can withstand any weather conditions and are resistant to chemicals. The worm can remain in one location for up to 10 years. Agronomic, chemical, and traditional methods are used to combat it.

Description of the parasite

These are small worms, 0.3–1.3 mm in size. They feed on the sap of plants belonging to the Solanaceae genus. A unique feature of nematodes is that sexually mature individuals are capable of developing into a cyst. The cyst contains approximately 200 eggs, which then develop into larvae and new individuals. The cyst can withstand any adverse weather conditions: drought, flooding, and frost.

You can notice the damage by seeing worms on the tubers and roots. At the beginning of development the lower leaves of the potato are turning yellowThe tops dry out, the plant develops poorly, and the tubers are small and loose. The parasite appears on the tubers as small, golden or white blisters. It firmly attaches to the roots. Because the potato nematode enters the cyst stage at the end of the season, control is difficult. While it may be possible to eliminate it for one season, the infestation will recur the following year.

Important! Potato nematode infestations can result in up to 80% yield losses. Control measures are essential.

Types of potato nematode

Currently, approximately 10,000 species of parasites are known. The most common species that affect potatoes are:

• golden;
• stem;
• leaf;
• gallic.

Golden

The parasite penetrates the roots and feeds on their sap. The plant begins to dry out from the lower leaves, the tops darken, and the bush wilts. White and golden blisters are visible on the tubers. The golden blisters are fertilized females about to enter the cyst stage.

Stem

Small worms, approximately 1 mm in size, attack potato stems and tubers. Dark spots appear on the potato skin, the fruit becomes loose, and black holes appear when cut. The parasite thrives in high soil moisture.

Sheet

The worms attack stems, leaves, and roots. They appear as small white balls. The plant begins to dry out and stops growing, the roots become small, and the plant lacks nutrients for normal development.

Gallic

This nematode forms large galls, up to 3 cm in size, on the roots. These galls prevent nutrients and water from reaching the potato roots. The tubers become lumpy and abnormally shaped. It attacks both stems and tubers.

Signs of pest presence

The first signs of parasitic infestation appear 45–50 days into the growing season. Infected bushes are distinguished by the following characteristics:

• slow growth of green mass of the bush;
• yellowing of lower leaves;
• drying out of tops before the harvest time;
• curling of leaves;
• uneven stem shape;
• small fruits;
• the roots are stained brown;
• lack of flowering;
• the appearance of small white or yellow balls on the tubers;
• loose structure of the root vegetable;
• black spots on tubers.

Methods of struggle

Nematode control involves agronomic, chemical, and traditional methods. A combination of all methods ensures a high kill rate.

Nematode is a quarantine disease, so it is recommended to report the presence of the parasite to the phytocontrol service.

Agrotechnical

When planting potatoes, add manure, chicken manure, and ash to each hole. This enriches the soil with minerals, which negatively impact nematode development. Adding any mineral fertilizer will have the same effect. For potatoes, select fertilizers containing nitrogen, phosphorus, potassium, copper, cobalt, and manganese. These measures create unfavorable conditions for worm development.

Important! To combat nematodes, it is essential to practice crop rotation.

Chemical

Chemicals are toxic and are therefore used only in advanced stages. Bazudin is used to combat parasites. It is prepared and sprayed according to the instructions, observing safety precautions. Chemical methods must be combined with agronomic and biological ones to completely eliminate nematodes.

Traditional methods

Before planting tubers, an infusion of potato sprouts is sprayed on the bed. Larvae begin to emerge from the cysts in search of food and die due to lack of it. Marigolds, calendula, beans, and sweet clover are sown between the potato rows. These crops release substances that repel pests.

Applying organic fertilizer between rows attracts annelids, which destroy the small parasites. Wood ash is rich in beneficial minerals and is added to the soil before planting to repel pests. Folk remedies are the safest treatments; they don't damage neighboring plants or potatoes and don't accumulate in the soil.

Preventive recommendations

To prevent nematode development, it is necessary to follow agricultural practices for growing potatoes. These include:

• selection of potato varieties resistant to nematodes;
• the right place for planting the crop, without excess moisture and with good drainage;
• compliance with crop rotation;
• choosing healthy seeds;
• disinfect seed material before planting with a solution of manganese or Epin;
• process garden material;
• carries out soil digging in autumn and spring, removing weeds, plant roots and stones;
• carry out fertilizing in a timely manner;
• water potatoes regularly;
• carry out hilling, loosening and weeding.

Important! Use of nematode-resistant potato varieties should be limited to 4 years, as the parasite develops a tolerance.

Danger and harm to humans

Potato nematodes do not affect the human body and do not cause any harm. Affected tubers are edible unless severely damaged. Other nematode species, whose eggs are found in soil, enter the human body, attach to the intestinal wall, and become parasitic. Infection is possible through unwashed hands and vegetables. The disease slowly affects all internal organs and systems; the parasite can be eliminated with anthelmintic medications.

Potato varieties resistant to nematode

The most popular nematode-resistant varieties are:

• dolphin;
• Belorussian;
• Zhukovsky;
• karatop;
• Lukyanovsky;
• frigate;
• virgin forest;
• latona;
• fresco;
• prior

These varieties are the most resistant to nematodes. Growing these potato varieties can eliminate the parasite. Since they cannot feed on the tubers of these varieties, the worms will slowly leave the plot and die. This variety is planted for four years in a row, then replaced with another.