Biological products for plant
Biological preparations are means obtained from various natural sources (fungi, plants, animals, microorganisms, etc.) or synthesized by biotechnological methods. Among other useful areas of application of such drugs, one can also name the protection of cultivated plants from diseases and pests.
The main feature of such biological means of protection, in contrast to “chemical”, means, is their harmlessness to humans and the environment (including domestic and wild animals, pollinating insects, etc.), which makes them suitable for more and more popularity of ecological (organic) farming. In addition, such drugs do not cause addiction in pests and resistance in pathogenic microorganisms – this allows you to effectively use the funds for many years without increasing the consumption rate of the active substance.
And also – biological products do not accumulate in plant tissues, do not adversely affect the quality and taste of fruits, and do not require a long waiting period (time between repeated treatments). In addition, some of them not only fight infections or pests but even strengthen the immunity of horticultural crops or increase yields. Especially useful is the treatment with such biological products of the soil for seedlings, as well as seeds and plants at a “young” age – at the most tender and sensitive stage – seedlings.
Just like poisonous chemicals, biological agents are divided into:
bio fungicides – drugs that suppress the vital activity of pathogenic fungi;
bioinsecticides – directed against insect pests;
acaricides – directed against pathogenic ticks;
bio nematicides – directed against herbivorous nematodes;
bioherbicides – means against weeds;
biopesticides – anti-rodent agents.
Do biologics have any drawbacks?
Rather, the nuances of use, the weight of which each gardener determines personally for himself and his site:
most of them act slower and softer than chemical analogs;
the action is short-lived, and the treatments will have to be repeated at regular intervals;
effectively cope with diseases only in the early stages. To get a significant effect, you need to carry out preventive treatments;
the shelf life of most biological products usually expires after 1.5-2 years, after which their activity begins to noticeably decrease.
Biologicals for plant pest control
These are drugs based on highly specialized viruses, fungi, microorganisms, and/or specifically targeted substances produced by them. They are designed to combat adults and larvae of harmful insects, ticks, and worms. Getting with particles of eaten foliage into the body of pests, the drug most often causes intestinal paralysis in them or, penetrating further into the tissues, serious metabolic disorders in the cells, which leads to death.
Also, the mechanism of action can be based on mechanical immobilization and/or damage to the eggs of pests and their adults (for example, the spores of the fungus Paecilomyces lilacinus germinate “through” the eggs of nematodes, destroying their contents). Sometimes such drugs are developed on the basis of other organisms – for example, nematodes can be used to fight insects.
Such drugs have a wide spectrum of action, which allows them to effectively deal with such pests as:
spider mite;
beetles, Colorado and May beetles and their larvae;
aphid;
thrips;
nematodes;
sawflies;
bedbugs;
butterflies (moths, scoops, moths, cabbage, American white, etc.);
fruit moths;
many types of caterpillars, etc.
Plus – many of these drugs have useful “side effects” such as enriching the soil with available forms of nitrogen or increasing the yield of products.
How are such drugs created?
Exploring the interactions of living organisms with each other. So, in the 19th century in Thuringia, while investigating the causes of death of the silkworm in a silk factory, they discovered a special bacterium, Bacillus thuringiensis, which secreted toxins that kill butterflies and beetles, but completely harmless to mammals. And already in the 20th century, preparations against insect pests were developed on the basis of these bacteria.
The most popular among gardeners are preparations based on:
bacteria Bacillus thuringiensis, available in the form of water-soluble powders;
microscopic fungi (Streptomyces, Verticillium, Metarhizium, Paecilomyces, Arthrobotrys, etc.), emitting special substances – neurotoxic poisons for insects and mites – or mechanically damaging the integrity of the integumentary pests;
entomopathogenic nematodes from the families Steinernematidae and Heterorhabditide, which as parasites are capable of infecting more than a thousand species of insect pests from various orders, affecting all phases of development, except for the egg;
highly specific viruses that infect specific harmful insects at the caterpillar stage.
Biologicals for the fight against plant diseases
There are a lot of antifungal biological products, but most often gardeners use products based on the bacterium hay bacillus (Bacillus subtilis) and the soil fungus Trichoderma (Trichoderma).
Hay stick was first isolated from hay broth, which is why it got this name. This bacterium is able to suppress the development of phytopathogens, producing more than 70 types of biologically active substances. Its effect on phytopathogens consists in creating unfavorable living conditions for them (acidification of the soil), as well as nutritional deficiencies – the hay bacillus develops faster than pathogens and populates the maximum surface.
Trichoderma, penetrating the roots of phytopathogenic fungi, actively grows in cells, which leads to the death of the latter. In addition, Trichoderma inhibits the growth and development of pathogens by releasing a large number of special enzymes and antibiotics.
Another important and remarkable ability of Trichoderma and hay bacillus is the processing of organic substances into inorganic compounds easily assimilated by plants.
Some drugs even contain several active microorganisms at once and even plant extracts that interact effectively.
How and when to treat the soil with biological products?
Each product has instructions for use. Usually, the drug is dissolved in water, and in the spring, a few days before planting the seedlings, the beds are shed according to the algorithm indicated on the package. In the greenhouse, a solution of the same concentration is used, but not only the soil is shed, but at the same time the walls and the ceiling are sprayed.
Such biological products are widely used in pre-sowing seed treatment. With such a disinfecting treatment (usually soaking in a working solution for 30-60 minutes), pathogens are effectively destroyed without harm to the seeds themselves and future seedlings. In addition to destroying the pathogenic fauna, biological products accelerate germination and increase the plant’s immunity to viral, bacterial, and fungal diseases. In addition, these preparations are usually very economical to use and act quickly, which significantly reduces the time for soaking the seeds.
