Nematode on the site - who is it and how to deal with it?
It used to be that if a nematode started up on a site, then you can safely drop it, sell it, build a house on it or lay a road along this site. People did not know how to get rid of the nematode, and waited for years of her death from hunger before planting a site that had previously been infected with a nematode. It is simpler to introduce a nematode and there is no need to describe all kinds of methods: for example, it is enough to buy a rose with a clod of earth, and the nematode is already on your site, period. But how to deal with it? We will talk about this in the article.
- Nematode biology
- What is the danger of a nematode?
- Read more about the root nematode
- Stem and leaf nematodes
- Beetroot nematode
- Potato Nematodes
- Nematode control measures at the site
- What is fumigation?
- Draw conclusions about the nematode
Nematodes are, according to some classifications, peculiar roundworms, and according to others - gastrointestinal worms. The species of these creatures described more than three tens of thousands, however, most likely, they are much more. The overwhelming species of nematodes are parasites of various plants, they can also live peacefully in the organisms of fish, humans and animals. Nematodes are far from harmless creatures, they cause a wide variety of diseases in humans, animals and plants.
The length of the nematode body can vary greatly (from 80 microns to several meters, if we keep in mind certain types of parasites). Nematodes have a specific fusiform shape, narrowed at the ends. The body is round in diameter.
Here we will talk about nematodes parasitizing on plants, and in the light of modern science, we will try to fight them so quickly that in the next season after infection we can plant or plant something on the site.
Let's start with the species of nematodes that annoy plants. It is usually very difficult to understand that your site is infected with a nematode; there are few signs of the manifestation of its activity. For example, you see that seedlings are slowed down in development or there is almost no growth and development of seedlings, or flowering is weak, or the death of plants at a young age is suspiciously significant, or the crop massively dies.
All this can be either a sign of a nematode, or a sign of other diseases or pests. The reason for the unhealthy plants may be a simple lack of any one or group of elements in the soil. Therefore, if the same picture is observed for the next year, we advise you to take a soil sample by digging a shovel into a bag and take it to the laboratory, they will tell you if this is a nematode or something else, otherwise you will treat the plants from one , then from another, not getting the proper effect and just massively multiplying the worst enemy.
What is the danger of a nematode?
In the process of its active life, it penetrates into the roots or vegetative mass, violates the integrity of the plant, causes rot, infection of the roots and vegetative mass with viruses, fungal infections, bacteria.
It is possible to understand that the nematode attacked the roots, if the plant that started to lose weight was pulled out of the soil completely and thoroughly examined its root system. When infected with a nematode, you can see a large number of branches on the roots, as if the plant tried to find ways to bypass, getting rid of the pest.
At the same time, the smallest roots will most likely look rotten. In addition, on the roots, if these are not legumes, you can see galls, these are literally clusters of nematodes, cysts with eggs, as well as sharpening and bloating, various kinds of ulcers - all this is mortally dangerous for the root, and for the whole plant as a whole.
Read more about the root nematode
So, the root nematode is, in fact, a filamentous worm, belonging to a very large group of parasitic worms and a class of nematodes that form galls on the roots of plants, somewhat similar to those of legumes (only gallbum bacteria in these galls, and females stuffed with eggs).
The males of the root nematode are in the form of a worm up to two millimeters in length, the females are more bloated (galls) or similar to egg capsules, half as long as.
The earthen nematode is surprisingly multi-species: it is reliably known that it can affect the root system of more than two thousand plant species. Of course, this group includes cultivated vegetable plants, various valuable industrial crops, as well as ornamental plants, herbs, shrubs and even trees.
It passes its full development to a real active organism depending on the temperature in the soil within 20-50 days (when it is warmer, the development passes, as a rule, faster). It is noteworthy that a female nematode in her life can lay a monstrous number of eggs - up to two thousand, and according to the latest information - and more.
In each egg, the nematode larva first molts, then comes to the surface and, thanks to tapering at the ends, immediately penetrates the root of a nearby plant, beginning to intensively feed on the juice of this culture. She can become either an immovable female, which subsequently lays the same huge number of eggs, or a male, who can move freely, looking for a female for her fertilization.
Nematodes grow most actively and develop at moderate soil moisture (about 70-75%) and a temperature of +22 to + 28 ° С. As for the acid-base balance, they prefer a slightly slightly acidic soil, but not alkaline.
Stem and leaf nematodes
In addition to soil nematodes, there are leaf and stem nematodes. Most often, they lead to a fusiform thickening of the stems, while the leaves are either underdeveloped to normal size and shape, or a strong deformation of leaf blades occurs in a variety of plants.
Usually, more accurate evidence of the presence of a nematode on the leaves is dry necrotic spots of various shapes that do not have any pattern in location. Most often, leaf nematodes are infected: garden strawberries, chrysanthemum and nephrolepsis. The stem nematode is not averse to feasting on vegetable crops, for example, garlic, onions, parsley, parsnip, radishes, tomatoes and cucumbers.
Consider the types of nematodes for the most important crops, and the first in this list will be table beets
It is interesting that before the presence of a nematode on beets was not officially recognized and for some reason the disease was called beet fatigue: supposedly, when growing in the same place, even the application of fertilizers did not help to get good results. But then everyone found out that a nematode also happens on beets, and it is very rampant.
To understand that the beets are infected with a nematode, in fact, is quite simple, for a start you can see a clearly noticeable browning of its leaves, and if you pull out such a plant, you can see a root crop rotted by half (or slightly less), which can only be thrown away, because it cannot be recycled. Often, root crops can be whole, but they lose much weight several times, and are not stored at all, they can only be used for processing. From a plantation infected with a nematode, you can collect no more than half of beet root crops devoid of their maximum mass
Another vegetable that most often affects the nematode is potatoes. It is extremely easy to infect your plot with this misfortune, it’s enough just to buy seed in an unverified place and you can put an end to it for many years (or start using harsh chemistry). The fact is that even if you cut the purchased tuber, you may not notice the larva hiding in the potato at all, and only after it is placed in the soil does it emerge in the form of a worm.
Potato nematode is a roundworm reaching about a millimeter in length, which can parasitize both on the roots and on the potato tubers. Worms usually move to the tuber from the roots if the soil is poor in nutrition and the roots are very thin.
The process of vital activity of a potato nematode is very interesting. After the worms exit the tuber, the females attach to the end of the root and wait for the male, and the male in search of the female can move along the roots of the potato, causing damage to the plant, and when it finds a female, it dies after fertilization. After that, the female actually dies too, she turns into a cocoon-cyst, in which up to thousands of individuals of different sexes are in the form of eggs, they naturally remain in the soil after digging potatoes.
The next spring, when the potatoes are planted in this place, the cysts burst, the larvae come out and everything repeats again.
It is clear that the nematode strongly inhibits the development of potato plants, the crop falls significantly, and if the soil is poor, then the nematode simply does not absorb food from the roots of the plants, and in the holes you can find no more than a couple of small tubers.
Externally, you can see that the plants are far behind in growth from their counterparts, in warm weather they seem to curl, because the nematode does not absorb moisture from the soil, and if you pull the plant out of the soil, you can also find a huge number of thin roots unusual for potatoes.
In general, it is possible to describe various kinds of nematodes on various plants for a long time; better, let's move on to the story about measures to combat this infection.
Nematode control measures at the site
If the nematode somehow got to your site, then you just have to listen to the professionals, although many advise just to wait two or three years, keeping the plants under black steam, digging the site under the winter with a lump of land, without breaking the clods, and then you, maybe exterminate the nematode.
But if you want to get rid of it as soon as possible, then first try using crop rotation. That is, in the area where the beet nematode was noticed, do not plant beets anymore, and if you notice potato, then - potatoes. Perhaps, in this way, it will be possible to get rid of a certain type of nematode in its area.
After a crop rotation, which is unlikely to help, a heavier technique works, it is fumigation, which at the moment is the most effective means of combating the pest, but it is also harmful.
What is fumigation?
This is the treatment of soil that is definitely infected with a nematode (for which samples and analyzes are taken in advance) with various highly active poisons and even their pairs, sometimes in a red-hot form. In principle, the pesticides themselves can even be bought on the market now, these are Nefamos, Dimetoat or Vidat.
These drugs can both treat plants infected with nematodes and shed the soil with them. These drugs are quite dangerous and we would not recommend just pouring chemistry, but it is better to entrust this matter to professionals who can reliably process the site and destroy not only adult nematode worms that die almost immediately, but also much more tenacious larvae, which sometimes require several treatments.
The following year, it is better to carry out a control planting at this site, taking, say, a third of the site with a variety of crops and check if the nematode remains in the soil.
Draw conclusions about the nematode
Nematode is a dangerous pest, you need to be careful when buying seed, plants in closed ground, and just seedlings with parts of the ground. It may be especially annoying for owners of small plots who have to wait years for at least something to be planted on them, or add liters of chemistry to fight harmful infection without a guarantee that somewhere there was still no cyst with a couple of thousand eggs.
Remember that the nematode is both an external and an internal quarantine object. You cannot sell products infected with a nematode; you cannot transplant plants to other sites from sites infected with a nematode. If the potato is grown on a site infected with a nematode, then it can only be put into processing, and best of all, feed for farm animals.
If you have ever dealt with a nematode, describe your experience in the comments to the article, perhaps it will be very useful to some of the readers.