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Potato cancer is one of the most dangerous diseases, affecting mainly potato tubers, and has recently spread widely not only in many countries of Europe, but also on other continents.
Description of the disease
Potato cancer, or Synchytrium endobioticum, belongs to the class of chytridiomycetes (Chytridiomycetes), classified as quarantine objects, as a result of which it is better studied than other diseases from this subgroup. The disease is currently registered in almost all regions of potato cultivation, with the exception of the extreme northern and southern regions.
Today, about 18 pathogens of the harmful fungus are known, but most of them are not found outside the borders of Central Europe. The most widespread distribution, including in our country, has received patotype I (pathotype I). The fungus produces a thick-walled structure - sporangium, whose diameter is 25-75 microns and contains about 200-300 spores.
Synchytrium endobioticum belongs to the category of obligate parasites, which are able to infect a number of plants belonging to the nightshade family. The most favorable conditions for the development of this fungus are high temperature indicators at the level of + 18 ... +20 ° C, as well as a sufficient amount of moisture. Sporangia remain viable for 20-30 years.
Potato Diseases: Control Methods
External signs of damage
As a rule, the main foci of the disease are located on personal plots, and the pathogen affects mainly potato tubers and stolons. The lower part of the stems and leaves located on the lower part of the potato bushes are much less likely to be affected. The root system of the plant is not affected.
The fungus provokes the appearance on the potato roots of tuberous growths or characteristic tumors with an uneven, wavy surface that look like a sponge or young cauliflower. As a rule, the appearance of growths begins with the eyes on the tubers. Gradually, there is an increase in growths in size, browning, color change to black and destruction.
Throughout the growing season, the disease can spread fairly quickly through single-flagged zoospores. During the summer period, the formation of zoospores can be repeated. In autumn, resting cysts, covered with a lignified membrane, are formed in root crops. Having wintered in root crops, cysts germinate in the presence of favorable conditions.
In addition to the usual form, leafy, scab-like and corrugated forms can form on root crops. The scab form of cancer is characterized by the development of ulcerations and crusts on the surface of root crops. The corrugated form is characterized by the formation of highly wrinkled root crops.
To infect a plant and actively germinate cysts, high soil moisture on the potato field (at least 60%) and optimal soil temperature values (+ 18 ... +23 ° C) are required. The source of infection is infected root crops or cysts located in the ground.
Thus, the main causes of potato cancer can be attributed to the presence of a pathogen in the soil, a very narrow crop rotation, the cultivation of potato varieties unstable to the disease, the use of seed material of unknown origin and favorable weather conditions.
In addition to potatoes, tomatoes and other nightshade ones are often infected, but unlike potatoes, the lesion also affects their root system. The pathogenicity of the disease is very high, regardless of which pathotype has spread, and the yield in the affected areas is low. In addition, tubers with cancerous growths are not stored for a long time, due to very rapid decay.
Contaminated soil can be transferred with any root crops, on the root system of seedlings of fruit crops or seedlings, as well as on agricultural implements and equipment. The causative agent of the cancer can also spread with a stream of melt water or manure from farms where the affected root crops served as a forage base for cattle without being treated.
Methods of struggle
Currently, it is possible to effectively fight potato cancer and conduct quality treatment only with proper observance of a set of therapeutic and preventive measures.
|Methods of prevention and treatment||Technology|
|Quarantine Activities||Monitoring of transported seed and ware potatoes, as well as annual inspection of vegetable crops in border areas.|
|Chemical events||Aimed at eliminating new foci of the disease. Disinfecting the soil with a 2-2.5 percent solution of nitrafen (at the rate of 20 liters per square meter) or 96 percent chloropicrin (at the rate of 150 cubic cm per square meter).|
|Cultivation of crustacean resistant varieties||Cultivation of varieties "Voke", "Giant", "Imandra", "Temp", "Frem", "Chernigovsky-2", "Peace", "Pavlinka", "Dawn", "Impala", "not susceptible to new cancer types Nemeshaevsky pink "," Enchantress "," Victoria "," Veronika "," Murmansk "," Povirovets "," Chernihivchanka "|
|Agrotechnical events||A competent crop rotation using row crops, the use of organic fertilizers on potato fields, as well as the destruction of weed plants from the nightshade family.|
Vegetable growers who have experienced a defeat of vegetable crops with potato cancer should remember that it is strictly forbidden to use chemicals on your own to disinfect household plots and gardens. This procedure is carried out exclusively by specialists in quarantine and plant protection.