Potato nematode is a disease characterized by a clearly visible tuber lesion (see photo). The cause of the disease is a tiny worm that has a filiform shape. Actually, the name of the disease “golden potato nematode” comes from the name of these organisms (“nima” means “thread”, and “oides” means “similar” or “threadlike”). In nature, these tiny worms can be found in the surface layers of the earth (usually up to 10 cm in depth), and in the icy water of the Antarctic, and in a hot spring. Especially a lot of them are still in the soil (several million per square meter).
Lifestyle
Potato nematode pierces the wall of the plant cell with its mouth-spear and injects its saliva inside, which, in turn, processes the cell into material that is absorbed by the worm and at the same time facilitates the movement of the parasite along the tuber.
Most nematodes lay eggs either in the soil or directly on the roots of the victim plant. Potato nematode bears offspring in itself, becoming a kind of protective chamber. Each such tiny cyst can contain up to three hundred larvae. Life expectancy (or rather survival) is quite high - 10 years (and more).
Harm done
Larvae emerging from the cyst immediately begin to invade the root of the plant. The substance that injects the potato nematode destroys the tuber cells and thereby slows its growth. The stems are drooping, the leaves are fading. The plant eats a miserable, painful existence. Potato nematode spreads very quickly. Moreover, pathogens of other diseases penetrate into the affected tubers with greater ease. Yes, and the nematodes themselves carry viruses, preparing, in addition, the ground for other pathogens. For example, tuberous nematodes produce enzymes that make the plant susceptible to late blight.
Nematode - quarantine object
"Sick" potatoes were imported from South America and the mountainous regions of the Andes. It was from there that the spread of the nematode went around the world. Today the worm is found in 42 countries. And this is contrary to the fact that the nematode is a quarantine object. To overcome the distance of thousands of kilometers, as you know, the parasitic worm itself can not. They are carried by the person himself. How? Offensively simple: with planting materials, on wheels of cars, on irrigation systems, on processing tools, and even on your own shoes.
Unfortunately, there are more and more sites of infection with the parasite. It is possible that in the absence of effective methods of controlling the disease, potatoes (nematodes) will be recorded everywhere.
Protection and Prevention
Given such a high harmfulness, it is recommended that all gardeners and farmers who have found signs of vegetable damage by this parasite report this immediately to the plant quarantine inspection (there are representatives in all areas).
Now we can already talk about the breeding of varieties that are not very susceptible to the nematode. Among them are Latona, Anosta, Picasso and Impala (Holland).
New drugs have also appeared. Nematicide basamide granulate has already proven itself. It is used before sowing (planting) mainly in closed ground under tomatoes and cucumbers, by uniform dispersion and sowing into the soil of 40 g of the drug per square meter. Potato protection with this drug has not yet been studied.
In some countries, more radical measures are being taken - from treating production sites with heterophosomes (80 kg / ha) and thiazone (270 kg / ha) to digging the infected tops into the soil, followed by chlorination (pouring with bleach).