The experts of the "August" company told which plant diseases caused the greatest damage to Russian agriculture this year. Wet and cool weather in a number of regions provoked the rapid development of bacterioses of potatoes, which can deprive farmers of their crops. Wheat ophiobosis is rapidly spreading across the fields - this year a fungal disease was recorded not only in the south, but also in the Central Black Earth Region. An excess of moisture in the Kursk region and neighboring regions allowed powdery mildew to harm the ears of cereals. At the same time, the main problem of farmers in the Southern Federal District - drought - limited the spread of the most dangerous grain disease - fusarium, which under normal conditions can make grain poisonous due to mycotoxins. Nevertheless, the sales volume of fungicides from the 10 largest producers of pesticides in Russia in the first half of 2020 compared to the same period of 2019 increased from 17 billion to 21 billion rubles (excluding VAT): domestic farmers are spending more and more funds to maintain high yields ...
In 2020, agricultural producers from the Moscow, Nizhny Novgorod, Tula, Bryansk regions again faced an outbreak of potato bacteriosis, of which there are up to 7 species. Phytopathologists believe that the main reason for the development of diseases is the rather low quality of seed material in Russia: farmers often buy infected potatoes from each other, increasing its area. And those farmers who pay increased attention to the quality of products today check 50-70 samples of seed material before purchasing, but visual analysis helps to cut off only rotting specimens.
“Today it is impossible to detect latent infection with bacteriosis using the methods provided for by GOST, which seed potatoes must comply with,” says Dmitry Belov, head of the product development department of the August company. - The active phase of the disease can begin with the development of the stem - from the maternal or even from a new tuber. Commonly encountered is the blackleg, caused by bacteria from the genera Pectobacterium and Dickeya, which is also common on private farms. Sometimes diseases appear at the germination stage, but seedlings may not appear either - we observed this phenomenon on several hectares in the Moscow region three years ago. The problem is common, but this year bacterioses manifest themselves especially strongly due to weather conditions - an excess of moisture and a cool spring in the main regions of potato cultivation. Potatoes affected by bacteriosis can simply "leak out" during storage - sometimes this happens with whole warehouses. "
In the Southern Federal District this season, there was an outbreak of ophiobosis in wheat. This is a fungal disease with a very wide time window of crop damage: it can manifest itself from the third leaf phase and the tillering phase (the formation of shoots in cereals) to the booting phase, leading to the cessation of plant nutrition and, in particular, the forming ear. The disease is difficult to identify: at the first stages it is confused with rhizoctonia root rot, which has been affecting crops in the Southern Federal District in the past few years, which harms the root system and somewhat worsens plant nutrition, but the consequences are limited to this. Ophiobolism, in most cases, causes significant losses, and the damage from it can be up to 30% of the crop. The disease spreads rapidly in the fields - about 10% of the area is infected annually. This problem is especially typical for the Stavropol Territory, it is aggravated in the Krasnodar Territory, and in 2019-2020. isolated cases began to be registered in the Central Black Earth Region.
The spread of the disease, the specialists of the "August" company explain, is primarily promoted by disturbances in crop rotation, when grain crops are grown year after year on the same areas. There are no effective chemical means of protection against ophiobolez, however, the company recommends curbing its development with disinfectants and using fungicides against other pathogens in early spring - the immunity of plants free from other diseases copes better with ophiobolez.
Kursk, Orel, Bryansk, Kaliningrad and Voronezh regions, as well as the Republic of Bashkortostan this year experienced problems with powdery mildew, which is traditionally considered one of the most common diseases of cereals. It is found almost everywhere on winter cereals and develops in conditions of dense crops, low temperatures, and an adequate supply of moisture and fertilizers. With an increase in temperature and a decrease in the amount of moisture, usually in May, the disease "goes away" by itself - especially in the south of Russia. But this year, for example, in the Kursk region, the amount of moisture did not decrease, the disease began to approach the ears and the farmers had to start fungicidal treatments. The same reasons in the named regions contributed to the development of soybeans peronosporosis - this disease can spoil up to 20% of the crop.
Too frequent sowing of sunflower in the same area provokes the appearance of diseases such as rust, phomopsis, downy mildew, as well as a variety of rot - sclerotinosis, botrytis. Traditionally, rust infestations are typical for the Samara, Saratov, Voronezh and Volgograd regions, and in 2020 the trend of their spread has not changed.
However, an unusual phenomenon this season was non-infectious diseases of sunflower, namely temperature burns: parts of the plants died for no apparent reason, and analyzes did not show the presence of infectious agents. This was observed almost everywhere - from Stavropol to Volgograd.
And one more disease, noticeable outbreaks of which were noted in 2020, is pea rust, which damaged crops from the Central Black Earth Region to Altai.
“Rust initially appears as orange-brown spots on the leaves of the crop, and during the harvest season, spore clouds rise behind the harvesters in the infected pea fields. This is also a fungal disease, the outbreak of which was caused by wet weather in a number of areas. In addition, it manifested itself even in drought conditions in those regions where the "stock" of infection is high, as it happened, in particular, in Altai, "says Dmitry Belov.
In general, the expert notes that the main problem for most farmers in 2020 was not plant diseases, but drought. By the way, it is because of her that this year the crops did not suffer from such a dangerous disease as fusarium, which can not only reduce the weight of grain, but also make it dangerous to health due to mycotoxins. The defining moment for the development of Fusarium is moisture during wheat flowering - in the form of rain or dew. But in conditions when there was no precipitation at all, there were no conditions for infection. Previously, this disease caused damage to crops in the Kuban, in the Stavropol region, in the group of regions of the Central Black Earth Region, in the Altai - exactly where drought reigned this season.
On the other hand, experts of the August company state that in regions where there was enough moisture (this, in particular, Moscow, Smolensk, Bryansk regions), lodging of winter crops was observed. In itself, this is not a disease: cereals lodge when a strong ear is formed under good nutrition, but from an excess of moisture, the stem cells are in a weak state and it cannot withstand the wind. To prevent this, farmers use growth regulators to shorten and strengthen the stem due to the closer arrangement of the lower internodes to each other. But if measures have not been taken, then when the crops are lodged, the grain "flows" or begins to germinate directly in the ear, and the proximity of the grains to the ground as a source of infection provokes disease.
Against the background of an increase in the detected disease incidence of plants, agents for their control - fungicides - are rapidly conquering the domestic market. Thus, according to the 10 largest producers of pesticides in Russia, sales of fungicides in the first half of 2020 compared to the same period a year earlier increased by almost a quarter - from 17 billion to 21 billion rubles (excluding VAT). For comparison: the total sales of pesticides in the first half of the year increased by 18% - from 65 billion to 77 billion rubles (excluding VAT).
“The market for fungicides - drugs against plant diseases - is constantly expanding, - says Dmitry Belov. - In Europe, in monetary terms, it is larger than the market for weed control agents - herbicides, while in Russia it is their sales that still significantly prevail in the segment as a whole. In European countries with high crop yields, up to 4 fungicidal treatments are carried out per season. In Russia, last year this coefficient was equal to 1,5, perhaps this year it will approach 2. Today, domestic farmers everywhere improve the mineral nutrition of crops and are guided by the introduction of high-yielding varieties as opposed to varieties more resistant to diseases, but limited in yield. This allows us to predict that the fungicide market will continue to grow, and in terms of both an increase in the cultivated area and the frequency of treatments. "
Material provided by the press service of the company "August"