Presentation on theme: "Negative effects of pesticides and their control. How pesticide use affects health and the environment Other negative effects of pesticide use on crop production

5.2. Other negative effects of pesticide use on crop production

Target objects, for the suppression of which pesticides are used, usually make up no more than a few fractions of a percent in any agrocenosis. total number types.

For example, the consequences of the use of DDT in gardens are known: the death of "harmful" insects was accompanied by an outbreak of reproduction spider mites that did no harm before fruit crops. When the caterpillars of the white butterfly (Pieridae) were destroyed with the help of DDT, many predatory arthropods were also destroyed along the way, as a result of which the population of the white butterfly was not only restored, but also increased.

Let's take a few more examples.

U.S. corn crop losses from insects prior to pesticide use in the 1940s were about 3.5%. However, with the introduction of maize monoculture crop losses increased to 12%, despite a thousandfold increase in pesticide use. In general, from 1945 to 1989 in the United States, the use of insecticides increased 10 times, and losses Agriculture from suppressed insects…increased from 7% to 13%!

The story of the fight against one of the species of grasshoppers that infect rice in Southeast Asia is also typical. Mass reproduction of this species in the 1970s, as a result of rice monoculture in Indonesia, led to a shortage of millions tons rice (Indonesia's losses exceeded $1.5 billion in the mid-1980s). After that they were withdrawn resistant varieties and introduced new pesticides. After some success in this fight, the grasshopper again became a dangerous "pest". The reason was that, along with the grasshopper pesticides destroyed more hundreds of species of other insects - natural enemies grasshopper .

UNEXPECTED TROUBLE

“If we take a critical look at the situation with agricultural pests around the world, it becomes clear that the use of pesticides only contributes to their spread. This applies to species such as rice grasshopper, cotton bollworm, whitefly, cabbage moth and a great many other pests that live on almost all types of vegetable, grain, cotton and plantation crops. Pesticides destroy the natural enemies of pests, which fight them more successfully than pesticides..

Jeff Waage, director International Institute biological control.
Magazine "Our planet". 1997. V.8. No. 4. P.27.

Chemical technology has been replaced by knowledge technology- this is how they characterize the next stage of the struggle, when chemical means of protection were replaced by biological ones - breeding spiders, beetles, competing grasshoppers, dragonflies. Pesticide companies fought furiously to keep the chemical defenses alive, but Indonesia was heading for an environmental disaster.

A large-scale experiment was carried out at the initiative of FAO in 1986: 2,500 farmers used pesticides as usual (on average 4 treatments per growing season) and received an average rice harvest of 61 c/ha. Another group of 7,000 farmers used mostly biological protection (they averaged less than one chemical treatment per season) and received average yield 74 c/ha. As a result of the experiment , since 1987 , government subsidies for the use of 57 types of the most common pesticides have been discontinued in Indonesia .

AT last years FAO has carried out such experiments with similar results in the Philippines, Malaysia, Thailand and several other countries.

The second example relates to the practice of controlling "weeds" in rice paddies. The use of propanid (stama F-34 - a herbicide of the 3,4-D group) in rice fields first aroused delight in rice-growing countries due to the highly effective suppression of "weeds" from the genus Barnyard grass ( Echinochloa) . However, the displacement of barnyard bushes turned out to be the reason for the clogging of rice fields with weed-field red-grain wild varieties of rice. The latter, moreover, serve as active carriers of dangerous fungal disease rice - blasts (to combat it, the toxic fungicide zineb is used). Unlike barnyard grasses, red grain rice weeds can no longer be suppressed by any herbicides, since they belong to the same genus (and sometimes species) of plants as cultivated rice.

As for the rice itself, propanide reduced its height, slowed down the growth and development of the growth cone, the accumulation of dry matter, reduced the assimilation surface of the leaves, and lengthened the duration of the growing season, especially early-ripening varieties. Soon the use of propane was reduced everywhere.

A serious negative effect of pesticides on agriculture is the creation after their application favorable environment for mass reproduction of forms that were in small quantities before the use of pesticides .

One of the negative effects of the use of pesticides is related to their possible stimulating effect on suppressed objects . Thus, DDT and some other pesticides can accelerate the development and increase the frequency of generation change in suppressed species (for example, in the spider mite).

The same was observed in some control operations. colorado potato beetle. Sublethal doses of DDT, dieldrin and thiophos are not reduced, but in some way that is still unclear increase egg production of the Colorado potato beetle - by 33-65%. Back in 1976, there was evidence that in a number of US states the use of carbofuran (furadan) increased population of the Colorado potato beetle. Chlorophos in certain doses also stimulates development of the Colorado potato beetle.

Some insecticides can change the age-sex structure of the population so that the remaining individuals begin to produce more offspring. For example, in the Colorado potato beetle, after an initial sharp decline in its numbers under the influence of pesticides, the number of eggs in surviving individuals increases dramatically. Thus, the pesticides themselves include mechanisms that contribute to the accelerated development of resistance (through the acceleration of natural selection).

Many examples show that the number of rodents reduced by rodenticides (zoocides) recovers faster than those reduced by exposure to natural factors. So, puberty of gray marmots ( Marmota baibacina) proceeds faster in populations treated with chemical method. Here, the percentage of females participating in reproduction is higher in all age groups in the first 2 years after the use of rodenticides. In pesticide-treated populations, the growth rate of these rodents was in some cases higher.

A negative consequence of the use of pesticides is the need for special means crop protection from unwanted action pesticides : adsorbents, antidotes for plants, microbiological detoxification agents, etc. This not only significantly increases the cost of agricultural production, but also, most importantly, increases the chemical load on agrocenoses.

One of the directions in Western agriculture is the development of resistance to the action of any herbicides in cultivated plants. This allows stronger doses of herbicides to be used to control unwanted vegetation without harming the main crop. It turned out, however, that, for example, making corn genetically resistant to the popular herbicide 2,4-D is associated with a more than threefold increase in the incidence of corn infestation by aphids and a number of other diseases. final The result of breeding herbicide-resistant plant varieties has always been the growing use of herbicides and fungicides, an increase in the chemical load on environment .

The same will no doubt happen to the much-touted biotechnology approach. Here the direction of action goes along several paths.

First, they try to introduce a "resistance gene" to a particular pesticide or group of pesticides into the genome of the protected form. This makes the agricultural plant resistant to large amounts of pesticides, which should defeat enemies that have adapted to low doses. This approach cannot give long-term positive results. First, it is difficult (if not impossible) to increase resistance in this way to not one, but several pesticides, which are commonly used in practice. Secondly, increasing the doses of pesticides used does not have a lasting effect, also because the suppressed "pests" and "weeds" always win and increase in the end, despite the use of high concentrations of pesticides (see Chapter 6).

DANGEROUS "SUCCESS" IN GENETIC ENGINEERING

“Monsanto, a chemistry and biotechnology giant (St. Louis, USA), has announced that it has recalled “small quantities” of genetically modified canola seeds that contain an unsuitable gene that was introduced into the seeds by mistake.

Canola is a crop grown for livestock feed and for making oil for human consumption. Canola oil is used in low fat cooking, pharmaceuticals, food additives, confectionery, margarine, personal care products, lubricants, soaps and detergents.

Introducing an unwanted gene into a commercial product is the kind of error that has been predicted for decades by opponents. genetic engineering. Its proponents replied that this could not happen, both because of the quality assurance of the industry itself, and because of the heavy regulation by governments.

The recall was initiated by Monsanto Canada. The recalled canola seeds were genetically engineered to resist the effects of glyphosate, Monsanto's herbicide sold under the brand name Roundup. The idea is to treat "Roundup compatible" crops with this herbicide so that weeds are killed and the modified crops remain intact. Monsanto declined to say how many "incorrect" canola seeds were recalled (allegedly the number was "small").

Canadian government officials say the recall was large. The publishers of the Canadian Food Newsletter reported that a total of 60,000 bags of two types of canola seeds (LG3315 and LG3295) were recalled because either one or both types of seeds contained the erroneous gene. The recalled amount is sufficient to sow between 600,000 and 750,000 acres of land. When Monsanto discovered its mistake, some seeds had already been sown.

In Canada, there are three levels of approval for genetically engineered crops: ecological (cultivability), livestock (animal feeding) and human (human feeding). Two roundup-resistant canola crop genes (RT-73 and RT-200) have been approved, with only RT-73 approved for livestock and humans. However, the unapproved RT-200 gene ended up in seeds that now have to be recalled.

The presence of the unapproved canola gene in commercial product indicates that Monsanto's quality assurance program failed in this case and that Canada's biotechnology regulatory system is ineffective. In the US, it is even weaker.

Data recent history indicate that there may be serious problems in cases where genetically modified products appear on the market without due verification.

In 1989, a Japanese firm was trading in L-tryptophan, an amino acid produced by a genetically engineered bacterium. The final product unexpectedly contained traces of contaminants, causing between 5,000 and 10,000 people in the United States to become ill with the serious illness eosinophilia-myalgia syndrome (EMS).

Clearly, genetically engineered products need extensive testing before their effects can be understood. The idea that genes control only one characteristic of a bacterium, plant, or animal turns out to be wrong. Genes contain potential that can manifest itself in different ways depending on the environment in which the gene grows: a gene can develop in one way in one environment and in a completely different way in another. Testing in one environment cannot reveal what a gene will do when placed in another environment. This has been elegantly demonstrated by Craig Holdrege in Genetics and the Manipulation of Life: The Forgotten Factor of the Situation.

Danish researchers have shown that genetically manipulated genes (transgenes) introduced into crops, in field conditions can move into nearby weeds. Thus, genetic errors of the kind that happened in Monsanto's canola seeds could spread into the natural environment and permanently change the natural world in ways no one is prepared to understand."

Another direction of modern biotechnology is insertion into the genome cultivated plants genes that make a plant unpalatable, not eatable at all, or even poisonous to animal species that feed on its tissues or to “weed” plants that stifle its growth. And this path, despite its apparent attractiveness, is theoretically unpromising. Firstly, "pests" and "weeds" always develop resistance to an artificial gene after some time. Second, over time, there will be other organisms for which an unpalatable plant will be palatable (see also Chapter 6). In addition, the introduction of any new gene into a genome polished by millions of years of evolution will always lead not only to the emergence of toxicity or resistance, but also necessarily to the breakdown of the entire complex genetic system and, thus, not to strengthening, but to weakening the protected organism.

By affecting the content of trace elements and other substances in plants, pesticides can change nutritional value plants , as well as their storage capacity. Such an effect was found for OCPs on cereals and legumes. So, for example, the treatment of wheat crops with some fungicides (zineb, bayleton, tilt) against stem rust ( Puccinia causes a decrease in the quality of baked bread.

A negative effect of pesticides on the nutritional quality of wheat and potatoes was found.

Sometimes herbicide treatment can change taste qualities plants , and this can have dangerous consequences. So, after treatment with the herbicide methoxone (2M-4X), buttercups that were previously inedible for livestock begin to be eaten in in large numbers; this leads to severe poisoning and even death of livestock. There are cases where the treatment of fields with herbicides has made economically important plants available for consumption by leaf beetles.

Influencing the course of intracellular and intercellular biochemical processes in plants, pesticides can drastically change the agrotechnical qualities of cultivated crops. For example, herbicides of the group Sim-triazines and urea derivatives block the transport of electrons during photosynthesis, which leads to a change in the nature of plant vegetation. Prometrin inhibits the process of symbiotic nitrogen fixation and promotes the transition of legumes to the mineral type of nitrogen nutrition. As a result, the value of legumes as nitrogen accumulators is sharply reduced. Nitrogen content ( mg/10 plants) changed in soybean: control (without herbicides) – 1493; when treated with promethrin - 1092.

One of the negative consequences of the use of pesticides is danger of destruction of modern genetically very unstable varieties of high-yielding plants due to the rapid accumulation of mutations in them. For example, the use of herbicides such as linuron, cotoran, toluine and THAN on cotton leads to the rapid destruction of the genetic structure of varieties. The same effect is exerted by DDVF (dichlorphos), phthalophos, simazine, chlorophos on wheat varieties, as well as dilor, karbofos, TMTD (tiram) on tomatoes (in the latter case, the genetic consequences are not particularly pronounced immediately, but in the second generation).

It has been shown that pesticides can not only change the genetic structure of plant populations, but also cause damage to plants, sterility, ugly growths (morphoses) of vegetative and generative organs. So, in barley crops treated with pesticides, up to 70% of plants with modified ears were found. There are even known cases of culling crops for this reason. Treatment with 2,4-D and phoxime caused an 18-24-fold increase in the number of plants with morphoses in barley. Table 5.2 summarizes the effect of various pesticides (not only herbicides, but also insecticides, acaricides, nematicides and fungicides) on the occurrence of ugly plant forms.

Table 5.2. The effect of some pesticides on the appearance of ugly forms of plants (dwarfism, disruption of the structure of the ovary and ear, flower, leaves, etc.)

Plant	Pesticide that causes deformities
Corn	Avadex, ATA, polytriazine, promethrin, simazine, triallat, eptam
Wheat	ATA, atrazine, banvel-D (dicamba), polytriazine, simazine, triallat, phthalofos, chlorophos
Barley	ATA, banvel-D (dicamba), methoxuron, 2M-4X, 2M-4XM, 2M-4XP, triallate, monocrotophos, baytex, metaphos, MNNG, oxydemetonmethyl, triallate, TLC, phenyltrione, phosphamidon (dimekron), chlorophos, granosan
Peas, beans	ATA, atrazine, polytriazine, simazine, suffix, granosan
Cotton	ATA, maleing hydrazide
tomatoes	Dilor, karbofos, keltan (dicofol), fozalon, chlorophos, Bordeaux mixture, TMTD (thiram), fentiuram, cineb

Among other examples of the effect of herbicides on plant disease, we note the following.

After the introduction of the usual norms of gameran (terbutrin) and dicuran (chlortoluron), wheat was more affected by powdery mildew pathogens. Aresin (monolinuron) and simazine had the same effect on winter wheat plants. Herbicides such as methoxon (2M-4X), ioxynil, dicamba and some others increased the susceptibility of winter wheat to root rot by an average of 60% compared to the control. Treatment of grain crops with 2,4-D favored the development of diseases such as powdery mildew and Alternaria. This and other herbicides of hormonal action (2,4-DM, 2M-4HP) affect the development of helminthosporosis of bluegrass meadow. herbicides Sim-triazine group, having a high herbicidal activity in corn crops, at the same time stimulate the development of its dangerous disease - blister smut ( Ustilago maydis) .

Under the influence of pesticides change the elemental composition of soils . Some pesticides can increase the content of some micro- and macroelements in plants (nitrogen, phosphorus, calcium, potassium, magnesium, manganese, iron, copper, barium, aluminum, strontium and zinc) and reduce the content of others.

Pesticides can lead to the accumulation of ammonia compounds in the soil. Phosphamide and fluometuron (kotoran) contribute to an increase in the content of nitrates in the soil, and DDT, sevin and HCCH sharply reduce it. The content of nitrates in the soil decreases by 30-40% when using prometrin. Treatment with the herbicide 2,4-D leads to an increase in nitrates in the straw.

A serious and usually underestimated negative consequence of the use of herbicides is a sharp increased soil erosion. The lack of grass cover makes the soil defenseless against wind, rain, and melting snow. On grassless soil, erosion develops rapidly on slopes with a steepness of only 1-2%, i.e. more than 90% of arable land in Russia.

When using herbicides in forestry, mineralization processes are activated, the amount of organic matter in the soil decreases, and the total content of nitrogen and calcium decreases.

In conclusion, we emphasize: negative impact of pesticides on agricultural plants –hard fact . And this impact is much more serious and diverse than advocates of the use of pesticides believe.

The negative consequences associated with pesticides are mainly due to the destruction of biogeocenoses, in which the very existence and abundance of individual animal species are closely related. Pesticide, destroying the pest, destroys the bonds, thanks to which the number of this pest was maintained in natural conditions at a certain level. If such a pest develops resistance to the drugs used, then an outbreak (mass development) occurs, since the bonds that restrain this process are either broken or weakened.

Characterizing possible situations associated with the use of pesticides, it should be remembered that they always negatively affect the inhabitants of the soil, whose vital activity underlies the maintenance of soil fertility. In particular, pesticides (especially copper-containing ones) inhibit the nitrification process. There are cases when, as a result of excessive chemical load on the soil, phytopathogenic microorganisms occupied a dominant position in it. With intensive use of pesticides, sterilization of the soil is noted.

Herbicides affect microbiocenosis, disrupting homeostasis (sustained fluctuation around a certain average level of the number of individual groups or the activity of metabolic processes) causing stress (reversible depression, or temporary depression of vital activity), changing resistance and inducing a change in dominant forms, as well as causing repression (irreversible reactions) .

If microbiological activity is restored within 60 days. after exposure, the reaction of microbiocenosis is considered reversible; if the inhibition of certain forms of microorganisms by at least 50% is maintained until the end of the growing season, the reaction is considered irreversible.

When using herbicides against the background of the absence or weak development of grass cover, the likelihood of developing soil erosion processes increases many times over.

Water- the main component of the biosphere and an indispensable factor in the existence of the biota - is the main vehicle for pesticides. Soil and ground waters, inland water bodies and streams, and then the World Ocean, if available certain conditions become the end points of concentration of toxicants.

Regular use of persistent lipophilic pesticides in large quantities over vast areas will inevitably cause pollution of water bodies. Toxicants move with liquid and solid effluents.

Pollution surface water pesticides occurs due to direct entry as a result of accidents, as well as in case of violation of the rules for transporting and storing preparations, during the demolition of aerosols or pesticide vapors during their application, in the process of runoff of surface or drainage water from lands treated with pesticides. World practice of using pesticides shows that pesticides carry a potential hazard.

There are no non-toxic pesticides for humans.

Any pesticide, being introduced into the ecosystem, inevitably causes profound changes in it. As a result, the following can be stated:

ü Pesticides are characterized by a wide range of toxic effects on the living matter of the biosphere;

ü pesticides are toxic to humans and animals;

ü pesticides are always used against populations;

ü the effect of pesticides does not depend on the density of the population, but they are used only when the population of the object of suppression reaches high values;

ü guided by an erroneous understanding of the reliability of processing fields, lands, water areas, as a rule, they deliberately spend a significantly larger amount of drugs than necessary to destroy pests;

ü pesticide residues accumulate and bioconcentrate in food (trophic) chains;

ü there is a removal of residual quantities of pesticides outside the cultivated areas;

ü Pesticide-resistant forms of harmful organisms appear;

ü some useful organisms perish and deep violations of relationships in biocenoses occur;

ü the likelihood of long-term consequences associated with the pathological and genetic effects of a number of drugs on biota increases.

Huge damage to the ecology of the region is caused by chemical pesticides (insecticides, fungicides, herbicides) and low-quality mineral fertilizers both in open and in closed ground. Moreover, only 1-2% of the drug used has a beneficial effect. The rest of it remains on the plant, inhibiting its development, reducing the period of vegetation and fruiting, or falling on the soil, killing the beneficial microflora, stopping natural process decay and fermentation of plant residues.

Another negative effect of pesticides is the destruction of insect pollinators. About 80% of all flowering plants are pollinated by insects: bees, bumblebees and others. beneficial insects, which make up only about 20% of all insect species.

Pesticides cause especially great harm when they are used in greenhouses, where pesticide treatments are carried out not 1-2 times until the ovary appears on plants (as required by the instructions), but up to 30 times during the growing season. And the saddest thing is that processing is carried out a few days before harvesting cucumbers, tomatoes, peppers and green crops. With such pest control, the grown product itself becomes harmful to human health, since the whole is saturated with the strongest poisons.

Many pesticides change the nutritional value of plants - there is no carotene in carrots (data from the Lenfam enterprise), in apples - enzymes and vitamins. The high content of nitrates in vegetable crops reduces the ability to long-term storage and detrimental to soil health. It is known that vegetables grown indoors with the use of pesticides are stored, even in the refrigerator, much worse than those grown in the garden without their use.

It has been proven that pesticides can even change the technical structure of plants, cause damage to plants, their sterility, morphoses of vegetative genetic organs. Pesticides can dramatically change the agrotechnical qualities of cultivated crops.

At the same time, the forms of harmful insects suppressed by pesticides in any agrocenosis are no more than a fraction of a percent of the total number of species. Therefore, when using pesticides, not only objects are affected, but also many other species, which are a deterrent and the destruction of which leads to an outbreak of the number of suppressed forms.

To this it should be added that almost all types of insects develop resistance (from Latin - counteraction, resistance) to the pesticides used, which forced the development and use of more and more toxic and expensive drugs. Characteristically, resistance occurs in all groups of pesticides, regardless of their chemical composition.

The long-term use of pesticides in vast agricultural and forest areas, often with the use of aircraft, has led to large-scale environmental pollution. Moreover, the molecules of pesticides (this is especially true for persistent compounds) are included in the natural processes of migration and circulation of substances and are carried along with atmospheric flows over long distances. For example, in Antarctica, tens of thousands of kilometers from the zones of application, the ice shell has accumulated more than 2000 tons of DDT. Chemicals, along with water runoff from fields, enter rivers and lakes, accumulate in bottom sediments, and enter the World Ocean. But most importantly, they are included in ecological food chains: they get from the soil into water and plants, then into the organisms of animals and birds, and ultimately, with food and water, into the human body. And at every stage of migration, they cause harm and damage. However, since harmful insects adapt over time to poisonous properties of these substances and the effectiveness of pesticides falls, their number per unit of agricultural production has to be constantly increased.
Many are probably familiar with the history of DDT, a pesticide that was once extremely widespread. Its creator P. Muller was awarded the Nobel Prize. It seemed that DDT brought to mankind the long-awaited liberation from malaria, yellow fever, typhoid epidemics. However, later studies have shown that the consequences of using this drug are very deplorable.
The more stable and toxic the pesticides, the more serious their negative impact on wildlife and humans. At the same time, resistance to environmental factors ( sunlight, oxygen, microbiological decomposition, etc., the ability of pesticides to persist for a long time) determines their danger to a greater extent. Pesticides based on organochlorine, organophosphorus and carbamate compounds differ significantly in their resistance. DDT, a typical organochlorine compound, can circulate in the biosphere for more than 50 years. Moreover, its decomposition products (for example, DDE) are dangerous and persistent substances, sometimes more toxic than the original substance.
One of the mechanisms of negative consequences is the transfer and concentration of stable pesticides along the trophic chains. Resistant to certain pesticides, flora and fauna can accumulate them without decomposing. As a result, the concentration of the toxicant in the body can many times exceed its initial concentration in the environment. This process of biological concentration is of particular ecological importance in food chains associated with aquatic environment. A classic example of biological concentration is the accumulation of DDT and mercury preparations in seabirds. These birds are the final link in the trophic chain: sea ​​water- plankton - a fish that consumes plankton; - predatory fish - a bird that feeds on fish. At the same time, the concentration of the toxicant from the initial link (sea water) to the final link (bird) increases many thousands of times.
In 1988, the US National Academy of Sciences published a report stating that in the next 70 years, more than one million Americans are at risk of developing cancer caused by the presence of 28 carcinogenic pesticides in food.
According to Indian scientists, the abuse of pesticides in the next decade can provoke an explosion of cancers and mutations in developing countries. These genetic changes are irreversible.
Of all the chemicals that enter the human body with air, water, food, pesticides are considered the most dangerous. Persistent pesticides can accumulate in the adipose tissue of humans and animals, adversely affecting the nervous and cardiovascular system.
Pesticides are especially dangerous for children. In Russia, in areas of massive use of pesticides, the overall incidence of children "from six years old (diseases of the skin, digestive tract, respiratory organs, metabolic disorders, lag in physical development) is 4.6 times higher than in areas with the least chemicals. For 25 years, cases of allergic diseases have increased 300 times.
According to the World Health Organization, 500,000 people are poisoned by pesticides every year, more than 5,000 people die.
Studies have shown that persistent organochlorine pesticides are found in almost all organisms living on land and in water. The spread of DCT is global. Throughout the world, LCT, aldrin, dieldrin, hexachlorocyclohexane and other persistent pesticides are found in the tissues of birds, mammals, amphibians, reptiles, fish, mollusks and other inhabitants of land, sea and fresh water.
The content of pesticides in the tissues and organs of living organisms, just like any other pollutants, is much higher than in the environment. This phenomenon is characterized by the accumulation coefficient (the ratio of the concentration in the body to the concentration in the environment). The accumulation coefficients in animals living in water are very high: in fish - 10-15, in mollusks - 25 thousand. The content of DDT in various fabrics and organs of the same species varies considerably. For example, in the muscles of the North Atlantic cod, its concentration is 1-10 mg / kg, and in the liver - 180-1800 mg / kg.
At the suggestion of the UN in 1998, a convention was adopted within the framework of the environmental protection program restricting trade hazardous substances and pesticides such as DDT, mercury compounds and organophosphates. 95 countries took part in the international treaty.
The irrational use of pesticides in agriculture leads to their accumulation in the soil and food products. However, there is no doubt that an increase in the culture of agriculture, an improvement in the technology of applying pesticides, limiting their use in areas close to water bodies, and a strict dosage when applied to the soil can significantly reduce their negative impact.
Pesticide contamination of food. Most often food products contaminated with chlorine-, phosphorus- and organomercury compounds, derivatives of carbamic, thio- and dithiocarbamic acids, bromides. From the group of organochlorine pesticides, DCT, DDE, aldrin, dieldrin, and some others were found in products; from organophosphorus pesticides - thiophos, karbofos, etc.; from carbamates - sevin, cineb, etc. Organochlorine pesticides are found in animal and plant origin, and organophosphorus and carbamate compounds - mainly in plants.
The accumulation of persistent chemicals in food products is most often associated with a violation of the rules and regulations for their use, with an overestimation of the recommended doses of the drug, failure to comply with the deadlines for the last treatment of plants before harvesting (waiting time), etc.
In many cases, the cause of pesticide contamination of forage crops is their cultivation in the aisles of cultivated orchards.
The content of organochlorine pesticides in products of animal origin may also be associated with their treatment of slaughter and dairy cattle in order to combat ectoparasites.
Influence of pesticides on biogeocenoses. The ecological activity of pesticides depends on the nature of the ecosystem (whole or part of it), as well as on the physicochemical properties of the preparations used. Pesticides can be used to treat inland waters used for fish farming, land plot on which a crop, forest plantation, grassland, animal or plant population is grown.
The adverse effect of pesticides on individual populations is expressed in the destruction beneficial organisms(mainly insect pollinators and entomophages) and, consequently, the violation of the stability of the ecosystem with the subsequent reproduction of species undesirable for humans. For example, the mass reproduction of the red fruit mite noted in a number of countries during the treatment of fruit with DDT is associated with the death of predatory mites tiflodromid, and blood aphids with the destruction of the parasite tliafelinus. The cessation of the use of certain pesticides can cause an outbreak of pests that have been suppressed for a long time by pesticides.
As already noted, the adverse effects of pesticides to a decisive extent depend on the physicochemical properties.
long time in agriculture as chemicals In order to protect plants, inorganic pesticides containing arsenic, fluorine, and mercury, which are characterized by extremely high toxicity, were mainly used. They were used with great caution and in limited quantities. At the same time, pesticides of this class do not have the ability to accumulate in the body and rather quickly decompose under environmental conditions.
More significant violations in biogeocenoses are observed with the systematic use of persistent highly toxic pesticides, mainly organochlorine compounds, especially DDT and HCCH preparations. These drugs, as already noted, are poorly decomposed in water and soil, can accumulate in plants and animals, and therefore have a significant impact on many aspects of biogeocenoses.
N. N. Melnikov and his co-authors developed a scheme for the circulation of pesticides in the environment (Fig. 9). As you can see, pesticides, having a certain stability, not only accumulate in soil, water, food, but also participate in the cycle of substances.

Rice. 9. Circulation of chemicals in the environment

Pesticides Pesticides (from lat. pestis - infection and lat. caedo - kill) are chemical substances used to combat harmful organisms. Pesticides (from Latin pestis - infection and Latin caedo - kill) are chemicals used to control pests. lat. lat. lat. lat. Most pesticides are poisons, poisoning target organisms, but they also include sterilizers (substances that cause infertility) and growth inhibitors. Most pesticides are poisons, poisoning target organisms, but they also include sterilizers (substances that cause infertility) and growth inhibitors. Pesticides are mainly used in agriculture, although they are also used to protect food supplies, timber and other natural products. In many countries, pesticides are used chemical warfare with pests of forests, as well as vectors of human and domestic animal diseases (for example, with malarial mosquitoes). Pesticides are used primarily in agriculture, although they are also used to protect food supplies, timber and other natural products. Many countries use pesticides to chemically control forest pests and vectors of human and domestic animal diseases (such as malarial mosquitoes).

Herbicides According to their function, herbicides can be divided into several groups. One of them includes substances used to sterilize the soil; they completely prevent the development of plants on it. This group includes sodium chloride and borax. Herbicides of the second group destroy plants selectively, without affecting the necessary ones. For example, 2,4-dichlorophenoxyacetic acid (2,4-D) kills dicotyledonous weeds and unwanted trees and shrubs, but does not harm grasses. The third group includes substances that destroy all plants, but do not sterilize the soil, so that plants can then grow on this soil. This is how, for example, kerosene acts, apparently the first substance used as a herbicide. The fourth group combines systemic herbicides; applied to the shoots, they move down the vascular system of plants and destroy their roots. Another way to categorize herbicides is based on the timing of their application, eg before planting, before emergence, etc. According to their function, herbicides can be divided into several groups. One of them includes substances used to sterilize the soil; they completely prevent the development of plants on it. This group includes sodium chloride and borax. Herbicides of the second group destroy plants selectively, without affecting the necessary ones. For example, 2,4-dichlorophenoxyacetic acid (2,4-D) kills dicotyledonous weeds and unwanted trees and shrubs, but does not harm grasses. The third group includes substances that destroy all plants, but do not sterilize the soil, so that plants can then grow on this soil. This is how, for example, kerosene acts, apparently the first substance used as a herbicide. The fourth group combines systemic herbicides; applied to the shoots, they move down the vascular system of plants and destroy their roots. Another way to categorize herbicides is based on the timing of their application, eg before planting, before emergence, etc.

Fungicides Many fungicides are inorganic substances containing sulfur, copper or mercury. Sulfur was probably the first effective fungicide and is still widely used today, especially to control powdery mildew. Of the organic compounds, formaldehyde was the first to be used against fungi. Synthetic organic fungicides, such as dithiocarbamates, are now the most common. Streptomycin-type antibiotics are also used to fight fungi, but more often to protect plants from bacteria. A systemic fungicide travels throughout the plant and acts like an antibiotic, either curing diseases caused by fungi or preventing them from appearing. Fungicides are widely used to control mold. For example, sodium propionate is added to bread for this purpose. Many fungicides are inorganic substances containing sulfur, copper or mercury. Sulfur was probably the first effective fungicide and is still widely used today, especially to control powdery mildew. Of the organic compounds, formaldehyde was the first to be used against fungi. Synthetic organic fungicides, such as dithiocarbamates, are now the most common. Streptomycin-type antibiotics are also used to fight fungi, but more often to protect plants from bacteria. A systemic fungicide travels throughout the plant and acts like an antibiotic, either curing diseases caused by fungi or preventing them from appearing. Fungicides are widely used to control mold. For example, sodium propionate is added to bread for this purpose.

Insecticides Insecticides are generally classified according to their mode of action. Intestinal poisons, such as arsenic, poison pests that eat the plants they have treated. Contact insecticides, such as rotenone, kill insects when they land on the surface of their body. Fumigants, such as methyl bromide, work by entering the body through the respiratory tract. Insecticides are usually classified according to their mode of action. Intestinal poisons, such as arsenic, poison pests that eat the plants they have treated. Contact insecticides, such as rotenone, kill insects when they land on the surface of their body. Fumigants, such as methyl bromide, work by entering the body through the respiratory tract.

Environmental impact The use of pesticides helps to obtain stable crops and limit the spread of infections transmitted by animal vectors, such as malaria and typhus. However, the ill-conceived use of pesticides has also Negative consequences. It leads to the emergence of resistant species of organisms, especially among insects; destroys predators (natural enemies of pests) and other useful animals. Polluting the environment, pesticides also threaten humans: now they are found even in groundwater. The use of pesticides helps to obtain stable crops and limit the spread of infections transmitted by animal vectors, such as malaria and typhus. However, the ill-conceived use of pesticides has negative consequences. It leads to the emergence of resistant species of organisms, especially among insects; destroys predators (natural enemies of pests) and other useful animals. Polluting the environment, pesticides also threaten humans: now they are found even in groundwater.

Growing concern about the misuse of pesticides has led to the development of pesticide regulations in the United States and other industrialized countries. They cover all aspects of the handling of these products: their transportation, storage, disposal of empty containers, maximum allowable residual quantities and much, much more. Because of the danger they pose, organochlorine insecticides (chlorinated hydrocarbons) such as chlordane, DDT and others are being phased out, although they have undoubtedly brought some benefits to both public health and agriculture. Some fumigants that were previously used for gas disinfection of soil and stored grain are also prohibited. Growing concern about the misuse of pesticides has led to the development of pesticide regulations in the United States and other industrialized countries. They cover all aspects of the handling of these products: their transportation, storage, disposal of empty containers, maximum allowable residual quantities and much, much more. Because of the danger they pose, organochlorine insecticides (chlorinated hydrocarbons) such as chlordane, DDT and others are being phased out, although they have undoubtedly brought some benefits to both public health and agriculture. Some fumigants that were previously used for gas disinfection of soil and stored grain are also prohibited.

Why can't you use the same drugs all the time? - On the one hand, it negatively affects the environment and, accordingly, the person. Toxic chemicals accumulate in food chains, and pests adapt to them and stop noticing them. On the other hand, the advantages of new drugs that are more effective and less dangerous both for humans and for the environment as a whole are not used. As a result, where small amounts of a narrowly targeted pesticide that quickly decomposes into relatively harmless compounds could be dispensed with, gardens and vegetable gardens continue to be treated with huge numbers chemicals that, as they say, kill all living things.

Consequences Consequences Death of wild animals during the treatment of fields with pesticides; Death of wild animals during the treatment of fields with pesticides; Mass reproduction of pests after the use of pesticides; Mass reproduction of pests after the use of pesticides; The emergence of pesticide-resistant pests. The emergence of pesticide-resistant pests.

Live nature- this is not a passive object of our influence, it responds to it with an active adaptive reaction. This explains the emergence of pesticide-resistant pests, and their number is increasing. Living nature is not a passive object of our influence, it responds to it with an active adaptive reaction. This explains the emergence of pesticide-resistant pests, and their number is increasing.

Pesticide control methods Quarantine - a set of measures to prevent the spread of the most dangerous pests. Quarantine - a set of measures to prevent the spread of the most dangerous pests. Breeding - breeding plant varieties and animal breeds that are resistant to diseases and harmful insects. Breeding - breeding plant varieties and animal breeds that are resistant to diseases and harmful insects. Agrotechnical - methods of tillage, the introduction of crop rotations, compliance with the sowing period and harvesting technology and scientific advice the use of pesticides. Agrotechnical - methods of tillage, the introduction of crop rotations, compliance with the sowing period and harvesting technology and scientific recommendations for the use of pesticides. Chemical - the creation of new pesticides with a high selectivity of action and a high decay rate. Chemical - the creation of new pesticides with a high selectivity of action and a high decay rate. Physical - the fight against nocturnal insects (optical traps, incandescent lamps). Physical - the fight against nocturnal insects (optical traps, incandescent lamps). Biological - the use of pest parasites; predatory and insectivorous birds and mammals; microbes and viruses; synthetic analogues of biologically active substances. Biological - the use of pest parasites; predatory and insectivorous birds and mammals; microbes and viruses; synthetic analogues of biologically active substances.