Potato nematode: pest description and control methods
In our country, nematodes were identified at the end of the forties of the last century. In seventy years, this parasite has spread throughout the country from south to north. In total, there are more than twenty thousand species of nematodes in nature; these parasites are steadily expanding their range, causing problems in agriculture in different countries. The most dangerous nematodes for potatoes.
What it is?
The cause of many ills for agriculture can be a voracious parasite - a nematode. It does not pose a danger to humans, but the potato nematode, for example, can completely destroy the crop.
The worm has microscopic dimensions, but the description of indirect signs of infection is quite simple:
- plants slow down growth;
- leaves turn yellow and dry;
Nematodes can enter the body of a plant in different ways, which are quite difficult to trace. Microscopic worms can be brought by summer residents through untreated tools, they are also carried on shoes, spores can be brought along with moisture and wind.
Varieties
Potato plants are attractive to these types of nematodes:
- golden;
- pale;
- silvery;
- stem.
Golden
Especially dangerous is the golden nematode, which has been terrorizing Europe for more than a century.
And also this parasite is also called soil nematode. It mainly affects plants:
- pepper;
- tomatoes;
- potato;
- turnip;
- beets.
- legumes;
- pumpkin;
- cucumbers.
The parasite has a body 0.2-1.4 mm in size, the worm at an early age is white, in the mature state it casts a golden color. First of all, the roots suffer, from which the nematodes suck out all the useful substances. A pregnant cyst-forming female nematode increases in size by two to three times, becomes like a ball covered with a caramel-colored shell. One female can give birth at a time to two hundred offspring (sometimes this number can reach up to five hundred).
In early spring, parasites attack the plants and eat the roots. Up to two generations of these dangerous worms can change in one season. Fighting nematodes is not easy; their larvae are well protected and hardy, they are not afraid of:
- frost;
- floods;
- high temperatures;
- radiation;
- toxins.
Golden nematodes are able to be in a state of suspended animation for ten years.
stem
The stem nematode has a length of 0.9 to 1.9 mm. Females lay up to 350 eggs. Up to 5 generations can change in one year. The potato stem nematode is one of the brightest representatives of phytohelminths. It feeds on root systems:
- tomatoes;
- beets;
- garlic;
- Luke;
- sunflower;
- legumes.
Potatoes suffer the most from the stem nematode. The development of generation occurs from three weeks to two months, much depends on the ambient temperature. Wintering takes place in the form of eggs or larvae. Anabiosis is absent.
The stem nematode is very fond of the high moisture content in the air, if the summer is rainy and there is little sunlight, then the reproduction of the parasite occurs exponentially. Huge areas of useful agricultural crops can be destroyed in a short time.
pale
Pale potato nematode is a cyst-forming parasite of the heteroderite family. In addition to potatoes, it also affects:
- eggplant;
- tomatoes.
It reproduces in a bisexual way. Likes the climate of the middle zone. Fertility up to 450 individuals, size 375-532 microns.
The male does not feed for one week, he fertilizes the female and dies. The larvae emerge from the eggs in the spring and penetrate into the roots. After a short time, they are destroyed.
The range of the pale nematode (affects potato tubers) is the same as that of the golden relative. Such "kids" are able to completely eat the crop. Infection is possible from seed seedlings or soil. Parasite eggs are not afraid of low temperatures; the female lays them directly in the tuber itself. The incubation period lasts about three weeks.
Up to 90% of the crop can die when such a scourge appears. After the appearance of the nematode, it is not possible to plant any crops on such soil. Years of reclamation and processing of such a site will be required, sometimes the terms can be delayed up to ten years.
Another harm that the nematode brings to the plant. The action of the worms is a kind of battering ram, through the punched “gap” pathogenic microorganisms, a fungus attack the weakened plant, which “eat up” the remains of the culture.
The infected land is treated with toxins (insecticides), but it is very difficult to destroy cysts by 100%. Modern means of pest control can suppress the population of parasites, reduce the damage they cause. As practical experience shows, it is impossible to completely get rid of nematode larvae.
Signs of appearance
You can detect nematodes when there are obvious signs of its appearance on the leaves and stems of plants.This happens most often after 6-7 weeks after planting. Signs of a nematode infection:
- plant growth retardation;
- yellowness of the leaves, which are located closer to the ground;
- stem twisting;
- faded flowering;
- general underdevelopment of bushes;
- the roots are painted in a dark brown color.
When the growing season lasts, it is not possible to detect nematodes, just one “fine day” they suddenly appear everywhere everywhere. An indirect symptom may be thickening of the stems, as well as the fact that the bushes become too "curly". Another clear sign is the appearance of white spots on the tubers and loosening of the tuber structure. And brown spots may also appear, which quickly increase in size.
Prevention
Measures that can be effective are the observance of all crop rotation conditions. The probability of occurrence of this parasite is high in those areas where potatoes are grown from year to year for a long period. It is better to plant potatoes after legumes (or cereals), give the soil a rest and resume planting in four years.
After harvesting, the site should be well cultivated, removing half-rotten roots from the ground. Thoroughly wash and disinfect garden tools, often even a formalin solution is used for these purposes. In no case should tubers be planted if there is even the slightest suspicion of their "illness". Treat seedlings with antiseptics, just in case, rinse the tubers in warm water. Strengthen the immunity of seedlings by processing them:
- ash;
- superphosphate.
Plants must have good nutrition, which also contributes to the increase of their resistance. You need micronutrients such as:
- zinc;
- copper;
- potassium;
- boron
It is recommended to grow potatoes that have good resistance to nematodes. All these routine measures can reduce the risk of infection by this terrible parasite by nine-tenths. Special varieties of potatoes that are not afraid of nematodes:
- "Dolphin";
- "Picasso";
- "Pomegranate";
- "Color";
- "Belorussian";
- "Prior".
If the larva gets into such tubers, then where it has penetrated, the tissues of the potato die off, the parasite dies of hunger. But it should be remembered that it is forbidden to plant the same varieties, there is a threat of developing immunity in nematodes. Potato varieties should be changed every four years.
Bushes that are attacked are immediately dug up and burned, this is the only way to protect themselves from the parasite. An infected plant should not be shaken, cysts can easily scatter throughout the area; in this case, a large area will be affected, especially if the weather is windy. Plants affected by the nematode are often placed in a pit and watered with a chlorine solution. The nematode should be fought non-stop, this is a very insidious pest, its elimination is possible only with the help of complex systemic measures. In late autumn, areas where potatoes are supposed to be grown are treated with lime. In early spring, put in each hole:
- manure (two handfuls);
- wood ash (one handful);
- bird droppings (one teaspoon).
This method allows you to protect yourself from nematodes and feed the plants.
Bird droppings effectively allow you to destroy the larvae of the parasite. Make a solution in a consistency of 1: 20 and water the potatoes with this composition. On average, up to one bucket of this solution can go per square meter.
But you can also use urea or mineral fertilizers, they also prevent the reproduction of this parasite.Nematodes "love" annelids. If you treat the site with organic fertilizers in early spring, then you can attract the appearance of worms in large quantities. There are special preparations containing annelids ("Nemabakt", "Protection"). Plants can be planted around the perimeter that repel nematodes by releasing irritating substances:
- marigold;
- nasturtium;
- calendula;
- legumes.
If the plot area is infected, then it is sown with winter rye. This usually happens after the first week of September, then the plants will have time to develop before the cold weather. With the appearance of the first snowflakes, it is cut off, laid on the soil and finely crumbled with a bayonet shovel. The resulting mass is sprayed with the composition "Baikal EM" (the solution is made one to a hundred). After it gets warmer in the spring, and the snow melts, the mass is mixed with the soil, dug up.
Chemicals are recommended to be used only in case of severe damage, when there is no other chance to get rid of the pest. Substances are powerful toxins, therefore, safety precautions must be observed, they must be handled in accordance with safety regulations.
Nematode-resistant varieties are very popular in our country. There are more than seventy positions in the register of the Russian Federation. If taken as a percentage, then this is more than 30% of the total number of crops used.
The greatest result is observed in varieties such as "Impala" and "Rocco" (77% and 78%). Penetrating into the tuber of such a potato, the nematode larva does not find enough food in it, the parasite does not develop, and it dies.
Methods for treating potatoes
The chemical compound "Bazudin" helps to get rid of nematodes quite well, this is a fairly effective remedy that also allows you to solve the problem with a wireworm that kills plant roots and potato tubers.
It should be borne in mind that toxins themselves can only be a help, the fight against this dangerous parasite should be carried out by all methods according to the developed strategy. Just “pour and forget” with chemistry will not work, it will not solve the problem.
Nematodes must be controlled by supervisory authorities, in case of their appearance, it is necessary to report to the official organization - phytocontrol. Experts will be able to give practical advice on how to deal with this scourge.
It is important to carry out preventive measures, which are an effective tool in the fight against this harmful parasite.
For information on how to protect potatoes from nematodes, see the following video.