ORIGIN OF FUNGI APPLICATION IN PLANT PROTECTION

Fungi are a large and diverse group of organisms closely related to agriculture. Some of them are the causative agents of dangerous diseases of agricultural crops, while others are themselves grown by humans for human consumption. The types of fungi that are natural pathogens for a number of insect pests, as well as pathogens of plant diseases of a fungal nature are of a particular interest. Most fungi of this group are usually present in the soil and, from time to time, under favorable environmental conditions, cause outbreaks of epizootic diseases that significantly reduce insect populations.

The use of entomopathogenic fungi for pest control was first proposed by I.I. Mechnikov, the famous scientist in the second half of the 19th century. The famous biologist separated out, described and learned how to produce in the laboratory a strain of the entomopathogenic fungus Metarhizium anisoplae that infects about 200 species of insects, including the Colorado potato beetle. At the same time, Agostino Bassi, the Italian botanist, discovered that the fungus Beauveria bassiana causes a disease of mulberry silkworm called "white muscardine".

Their work was continued by I.M. Krasilschik, who studied the diseases of beet weevils, described the pathogen of the "red muscardine" Sorosporella uvella. In a short time, the scientist developed a technology for the production of a biopesticide based on the spores of this fungus and diluted beer wort. In just 4 months in 1884, the Muscardine Factory delivered 54 kg of Sorosporella uvella spores.

Laboratory tests showed the high effectiveness of the pathogen in controlling the pest, and the scientist being inspired by the results, talked about "an early victory over pests by creating artificial epidemics", but field research was needed. Unfortunately, the economic crisis in the sugar sector temporarily put an end to the scientist's tests. It is also worth mentioning that back in 1916, Florida farmers were using entomopathogenic fungi to control massive pests on citrus plantations.

Unfortunately, the mass production of effective chemical plant protection products suspended the development and introduction of biopesticides and they were remembered again only in the 60s due to the growing concern about the harm of chemical pesticides to human health and the environment. The first fungal biopesticide used on an industrial scale was produced in the USSR in 1965. This medicine Boverin contained spores and toxic metabolites of the strain of the entomopathogenic fungus Beauveria bassiana with high virulence to Lepidoptera. The drug has become a quality replacement for such active ingredients as imidacloprid and thiamethoxam.

An active increase in the share of fungal drugs on the biopesticide market has been observed only since the 80s. BotaniGuard and Mycotrol produced by the company Emerald BioAgriculture became the first widely used fungal pesticides. BotaniGuard was a liquid emulsion of B. bassiana spores and Mycotrol contained powdered conidium. Following these "pioneers", drugs based on B. bassiana began to be actively produced all over the world, for example, in France, Ostrinil was used to control corn moth for many years. Pesticides based on the entomopathogenic fungus Metarhizium anisopliae also have a long (but not always successful) history.

In the 1980s, Bayer Corporation produced the biopesticide Bio1020, which was a formulation of M. anisopliae with long shelf life and high potential for controlling black grape weevil and a number of other pests. However, the product was not a commercial success and was unavailable for many years thereafter. This drug has recently reappeared under the trade name Taenure.

Another interesting direction in the use of fungal preparations was the production of fungicides in the 90s of the last century, based on fungi of the genus Trichoderma, primarily T. harzianum and T. viridae. These drugs are called trichodermines and are capable of both preventing the development of fungal diseases by stimulating the natural defenses of plants and controlling pathogens by parasitizing them in the root zone.

Nowadays, in the world, the total volume of sales of biopesticides (and not only of fungal origin) is only 5% of the value of the entire plant protection products market, but their share is steadily growing by 10-20% per year. This state of things is explained in part by the greater complexity and cost of use compared to synthetic analogues, but it is undoubted that due to the increasingly frequent cases of the emergence of resistance, as well as the success of genetic engineering and breeding, the proportion of fungal pesticides will grow steadily.