What is a nematode and how to deal with it?

Crop production is an occupation that requires the farmer to pay constant attention to his own plantings in order to protect them in time from the invasion of unwanted guests. Nematoda is one of those enemies that you need to react to especially quickly, otherwise the consequences can be severe.

These pests are also called roundworms in another way, which describes their appearance well. At the same time, nematodes are not one biological species, but a large group of related species capable of infecting not only plants in the garden or greenhouse, but also animals.

For this reason, such parasites are doubly dangerous, but acquaintance with them should begin with an approximate description of the most common varieties.

• Stem... The name implies the main danger of such nematodes - they like to penetrate into the stem, blocking the transfer of sap and affecting all parts of the plant above the ground, poisoning them with the toxins produced. The pest is dangerous for vegetable and flower crops, often found on cucumbers and garlic, tomatoes and phlox. Thickening in the form of a spindle on the stems, their deformation with the appearance of cracks, brown corrugation on the leaves, loose tissue in the bulbs - all these are signs of the activity of the described enemy.
• Sheet... If the previous species chooses stems as a habitat, then this one, accordingly, lives in foliage. The effects of infection are best seen, again, in the leaves, which turn pale and yellow, thin, dry and eventually die. At the dacha, the consequences of the penetration of intruders are most noticeable for ornamental crops, but strawberries are also at risk.
• Root (gallic). Such worms live in the soil. A soil pest affects the root system, forming specific growths on its surface - galls, which interfere with the normal absorption of moisture from the soil. Lacking water and nutrients, garlic, beet and cucumber bushes begin to dry and wither for no reason.

The most obvious sign that a plant has developed a fierce foe is when you directly see nematodes. The pest looks like a very long, thin, whitish worm. The problem of its detection is that most often it lives in the roots, and can even penetrate into the structure of the plant, while it is practically not found on the leaves.

Accordingly, it is usually possible to suspect that an invisible enemy is hitting the garden bed only by the characteristic symptoms:

• the planted crop shows an unusually low germination rate;
• growth and development slows down significantly;
• on the leaves and other parts of the plant, visible deformations appear in the form of dark brown dead spots surrounded by a beige halo;
• flowering and fruiting show a marked decrease;
• adult plants begin to hurt often and for a long time, and young plants are able to die from any negative factor that is not expressed enough to kill greens alone.

Nematodes are an enemy that is considered very serious and difficult to remove, but at the same time theoretically allows you to save even those bushes that are already completely affected. This possibility is provided by the mechanical method. We will fight the enemy in the following way - all the affected plants must be carefully dug up and the rhizomes removed from them, dividing them into several parts. The method is practical only if the cultivated crop allows reproduction by division - then the divided bush can be continued to grow in the form of cuttings obtained. The worm could hardly affect the entire plant as a whole, especially if the farmer noticed the warning signs in time, because some of the cuttings obtained should be healthy.

The more cuttings made from a bush, the more likely it is that the percentage of healthy bushes will be high. At the same time, in order not to contribute to the spread of the infection, each stalk must be cultivated under quarantine conditions. This means that they cannot be grown in the same pot or in close proximity to each other.

You can also get rid of pests with the help of an increased temperature, after all, there are practically no biological species on earth that can withstand uncomfortable heat for a long time. In a sense, humans are lucky with nematodes - they are "burned" at a temperature that is still incapable of harming a cultivated plant. It is assumed that heat treatment will be safer for plants that are not currently in the stage of active growth, therefore, it is usually carried out during a dormant period. As a forced measure, it is allowed to use the technique when transplanting plants (which is already stressful).

The bottom line is to treat the affected areas of the plant with warm water: +50 degrees will be enough, such a temperature threshold should not be exceeded in order to avoid the possible appearance of burns already on the culture itself. The thermal method is most convenient for fighting rootworm nematode - the roots are simply dipped in warm water. It is enough to hold them in such a liquid for 5-15 minutes, after which a cooling session is required, when the roots are already dipped into cool water.

The simplicity of the technique would surely attract a lot of followers, but there is a problem: it is not potent enough to fight serious infection. Summer residents resort to heat treatment usually as a kind of prophylaxis - if the nematode has just penetrated into the plant, without having time to noticeably manifest itself and multiply, such an effect may be enough to defeat it. The method is good for quickly processing a large number of plants, but it is not suitable for saving a sick specimen.

All known types of nematodes are considered terrible and dangerous enemies of the summer resident, not only because of their gluttony and omnivorousness, but also because it is quite difficult to destroy them on the site - many "traditional" pest control drugs do not really work on them. However, humanity has not yet died out of hunger, which means that farmers have still found effective methods of combating the infection, allowing them to prevail over it.

If the easiest way to fight you consider the need to treat the bed with "chemistry", pay attention for specific drugsspecifically aimed at combating nematodes. They are called nematicides. The peculiarity of such substances is the ability to effectively kill worms without disturbing either the chemical composition of the soil or the balance of bacteria and fungi. Good examples of such drugs are "Aktofit" and "Fitoverm"... In both cases, it is a powder that must be scattered over the soil surface a few days before planting the seedlings and "drowned" in the soil using a cultivator. The preparations show good results in cleaning the soil from the most common root gall nematodes, but, alas, they will not help in any way in the case of plants that are already infected.

It is still possible to save a plant that has entered the growing season and shows clear signs of nematode infection, but this will require an order of magnitude more "heavy artillery". Knowledgeable summer residents are advised to use systemic drugs, such as Aldoxicarb, Alanicarb, Marshal and Karbofuran... Another thing is that all these substances are highly toxic not only for nematodes, but also for humans or pets, therefore, they can be used in everyday life with great care.

According to the instructions, they are resorted to mainly in open areas, while the use in greenhouses or even more so in a residential building is highly undesirable. Farms operating on an industrial scale must ventilate greenhouses before using such "chemicals", and also provide forced ventilation.

The enemy of my enemy is my friend, and this rule works not only in relations between people, but also in the fight against pests in the beds. In nature, there are practically no living organisms that do not have natural enemies, which means that the human task is to help ensure that such enemies of nematodes, harmless to agricultural crops, are present in the garden and have good conditions for reproduction. A number of organisms are capable of parasitizing the larvae of worms, preventing them from developing normally. This includes certain types of carnivorous (not "vegetarian") nematodes, as well as ticks and fungi. Such organisms can be purchased in the form of a biological preparation in stores for summer residents.

You do not need to spend money on the drug, stimulating the natural appearance of the necessary organisms in the soil. The simplest ways are to add organic fertilizers or even ordinary sugar dissolved in water to the soil.... Thanks to such additives, the number of saprophytes in the soil will grow many times over, and the necessary species will come after them. Here, however, it is important to understand that the presence of living creatures parasitizing on nematode larvae is only a deterrent for their reproduction and further spread, but it will not work to heal already diseased plants in this way.

Biological methods of control can include breeding not only predators, but also plants that can demonstrate phytoncidal properties, that is, scare off pests. Calendula and marigolds are some of the most popular phytoncides whose presence in the garden means that pests (and nematodes among them) will bypass the garden bed. However, the landing of such assistants is not needed somewhere in the corner and not around the perimeter of the garden - for full protection, they must grow between every two adjacent rows of the main crop.

All the described measures taken together are usually still unable to give a result of the level when the nematodes completely disappear from the site. The task is more realistic: if the enemy cannot be completely destroyed, it is necessary at least to keep its numbers under control. Naturally, it is more reasonable to spend energy not on fighting a strengthened enemy, but on counteracting the fact that it becomes too much.

The following are considered effective measures:

• regular and timely removal of weeds, which can also become a haven for breeding nematodes and additionally weaken cultivated plants;
• obligatory laying of manure in the soil;
• diligent spilling of the soil mixture and its subsequent drying, which repeatedly alternate with each other;
• planting on "alien" beds of legumes, as well as watercress - these plants are considered capable of resisting the spread of the most dangerous rootworm nematode, controlling its population on the site.