File Name: insecticides pesticides and chemical fertilizers project .zip
Pesticides are substances that are meant to control pests. As an example - The fungus Alternaria is used to combat the Aquatic weed, Salvinia. In general, a pesticide is a chemical such as carbamate or biological agent such as a virus , bacterium , or fungus that deters, incapacitates, kills, or otherwise discourages pests.
Insecticide , any toxic substance that is used to kill insects. Such substances are used primarily to control pests that infest cultivated plants or to eliminate disease-carrying insects in specific areas. Insecticides can be classified in any of several ways, on the basis of their chemistry, their toxicological action, or their mode of penetration.
In the latter scheme, they are classified according to whether they take effect upon ingestion stomach poisons , inhalation fumigants , or upon penetration of the body covering contact poisons.
Most synthetic insecticides penetrate by all three of these pathways, however, and hence are better distinguished from each other by their basic chemistry. Besides the synthetics , some organic compounds occurring naturally in plants are useful insecticides, as are some inorganic compounds; some of these are permitted in organic farming applications.
Most insecticides are sprayed or dusted onto plants and other surfaces traversed or fed upon by insects. Stomach poisons are toxic only if ingested through the mouth and are most useful against those insects that have biting or chewing mouth parts, such as caterpillars , beetles, and grasshoppers. The chief stomach poisons are the arsenicals —e.
They are applied as sprays or dusts onto the leaves and stems of plants eaten by the target insects. Stomach poisons have gradually been replaced by synthetic insecticides, which are less dangerous to humans and other mammals. Contact poisons penetrate the skin of the pest and are used against those arthropods , such as aphids , that pierce the surface of a plant and suck out the juices.
The contact insecticides can be divided into two main groups: naturally occurring compounds and synthetic organic ones. The naturally occurring contact insecticides include nicotine , developed from tobacco ; pyrethrum , obtained from flowers of Chrysanthemum cinerariaefolium and Tanacetum coccineum ; rotenone, from the roots of Derris species and related plants; and oils, from petroleum.
Though these compounds were originally derived mainly from plant extracts, the toxic agents of some of them e. Natural insecticides are usually short-lived on plants and cannot provide protection against prolonged invasions. Except for pyrethrum, they have largely been replaced by newer synthetic organic insecticides. Fumigants are toxic compounds that enter the respiratory system of the insect through its spiracles , or breathing openings.
They include such chemicals as hydrogen cyanide , naphthalene , nicotine, and methyl bromide and are used mainly for killing insect pests of stored products or for fumigating nursery stock. The synthetic contact insecticides are now the primary agents of insect control. In general they penetrate insects readily and are toxic to a wide range of species.
The main synthetic groups are the chlorinated hydrocarbons, organic phosphates organophosphates , and carbamates. The chlorinated hydrocarbons were developed beginning in the s after the discovery of the insecticidal properties of DDT. Other examples of this series are BHC , lindane, Chlorobenzilate, methoxychlor , and the cyclodienes which include aldrin , dieldrin , chlordane , heptachlor , and endrin.
Some of these compounds are quite stable and have a long residual action; they are, therefore, particularly valuable where protection is required for long periods. Their toxic action is not fully understood, but they are known to disrupt the nervous system. A number of these insecticides have been banned for their deleterious effects on the environment. The organophosphates are now the largest and most versatile class of insecticides.
Two widely used compounds in this class are parathion and malathion; others are Diazinon, naled, methyl parathion, and dichlorvos.
They are especially effective against sucking insects such as aphids and mites, which feed on plant juices. The organophosphates usually have little residual action and are important, therefore, where residual tolerances limit the choice of insecticides. They are generally much more toxic than the chlorinated hydrocarbons. Organophosphates kill insects by inhibiting the enzyme cholinesterase, which is essential in the functioning of the nervous system. The carbamates are a group of insecticides that includes such compounds as carbamyl, methomyl, and carbofuran.
They are rapidly detoxified and eliminated from animal tissues. Their toxicity is thought to arise from a mechanism somewhat similar to that for the organophosphates. The advent of synthetic insecticides in the midth century made the control of insects and other arthropod pests much more effective, and such chemicals remain essential in modern agriculture despite their environmental drawbacks.
By preventing crop losses, raising the quality of produce, and lowering the cost of farming, modern insecticides increased crop yields by as much as 50 percent in some regions of the world in the period — They have also been important in improving the health of both humans and domestic animals; malaria , yellow fever , and typhus , among other infectious diseases, have been greatly reduced in many areas of the world through their use.
But the use of insecticides has also resulted in several serious problems, chief among them environmental contamination and the development of resistance in pest species. Because insecticides are poisonous compounds, they may adversely affect other organisms besides harmful insects. The accumulation of some insecticides in the environment can in fact pose a serious threat to both wildlife and humans.
Many insecticides are short-lived or are metabolized by the animals that ingest them, but some are persistent, and when applied in large amounts they pervade the environment.
When an insecticide is applied, much of it reaches the soil , and groundwater can become contaminated from direct application or runoff from treated areas. Owing to repeated sprayings, these chemicals can accumulate in soils in surprisingly large amounts 10— kilograms per hectare [10— pounds per acre] , and their effect on wildlife is greatly increased as they become associated with food chains.
The stability of DDT and its relatives leads to their accumulation in the bodily tissues of insects that constitute the diet of other animals higher up the food chain , with toxic effects on the latter. Birds of prey such as eagles , hawks , and falcons are usually most severely affected, and serious declines in their populations have been traced to the effects of DDT and its relatives.
Consequently, the use of such chemicals began to be restricted in the s and banned outright in the s in many countries. Cases of insecticide poisoning of humans also occur occasionally, and the use of one common organophosphate, parathion , was drastically curtailed in the United States in owing to its toxic effects on farm labourers who were directly exposed to it.
Another problem with insecticides is the tendency of some target insect populations to develop resistance as their susceptible members are killed off and those resistant strains that survive multiply, eventually perhaps to form a majority of the population. Resistance denotes a formerly susceptible insect population that can no longer be controlled by a pesticide at normally recommended rates. Hundreds of species of harmful insects have acquired resistance to different synthetic organic pesticides, and strains that become resistant to one insecticide may also be resistant to a second that has a similar mode of action to the first.
Once resistance has developed, it tends to persist in the absence of the pesticide for varying amounts of time, depending on the type of resistance and the species of pest. Insecticides may also encourage the growth of harmful insect populations by eliminating the natural enemies that previously held them in check. The nonspecific nature of broad-spectrum chemicals makes them more likely to have such unintended effects on the abundance of both harmful and beneficial insects.
Because of the problems associated with the heavy use of some chemical insecticides, current insect-control practice combines their use with biological methods in an approach called integrated control. Insecticide Article Media Additional Info. Article Contents. Print print Print. Table Of Contents. While every effort has been made to follow citation style rules, there may be some discrepancies.
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Learn which plants thrive in your Hardiness Zone with our new interactive map! While insecticides and other pesticides, along with the advent of chemical fertilizers, has helped farmers produce sufficient and even excess crops, the environmental and health impacts have been severe and are continuing to grow. Sometimes these chemicals are researched poorly if at all for their impact on human health or the environment. Sometimes misuse by the farmer or gardener leads to inadvertent harm. But the long-term impacts are poorly understood until the chemical load builds up in homes and the environment.
Overall effectiveness category Beneficial. Pesticide, herbicide and fertilizer applications may have a negative impact on farmland wildlife. This intervention may involve reducing or ceasing applications of pesticides such as insecticides, fungicides , herbicides and fertilizers. Several European countries Denmark, the Netherlands and Sweden introduced initiatives in the s to reduce pesticide applications Pretty Pretty J.
The impacts of pesticides on wildlife are extensive, and expose animals in urban, suburban, and rural areas to unnecessary risks. Beyond Pesticides defines "wildlife" as any organism that is not domesticated or used in a lab. This includes, but is not limited to, bees, birds, small mammals, fish, other aquatic organisms, and the biota within soil. Wildlife can be impacted by pesticides through their direct or indirect application, such as pesticide drift, secondary poisoning, runoff into local water bodies, or groundwater contamination. It is possible that some animals could be sprayed directly; others consume plants or prey that have been exposed to pesticides. Pesticide exposure can be linked to cancer, endocrine disruption, reproductive effects, neurotoxicity, kidney and liver damage, birth defects, and developmental changes in a wide range of species.
tence level in soil, factors affecting their toxicity and pesticide degradation. Keywords Chemical pesticides and fertilizers • Sustainable.
Details such as revenue, capital, total grant amount of money, etc are available. Users can view and download the files. Users can get details about the grant amount and related spending details. Contact details of officers of Department of Fertilizers, Ministry of Chemicals and Fertilizers are given. Users can get information about name of the officer, designation, extension number, office number, residence number, fax number and room number.
In recent years, people have been exposed to several types of substances with broad spectrum due to the rapidly evolving technology. One of these chemical substance groups are pesticides. Pesticides have been an essential part of agriculture to protect crops and livestock from pest infestations and yield reduction for many decades. Despite their usefulness, pesticides could pose potential risks to food safety, the environment, and all living things.
The term pesticide covers a wide range of compounds including insecticides, fungicides, herbicides, rodenticides, molluscicides, nematicides, plant growth regulators and others. Among these, organochlorine OC insecticides, used successfully in controlling a number of diseases, such as malaria and typhus, were banned or restricted after the s in most of the technologically advanced countries. The introduction of other synthetic insecticides — organophosphate OP insecticides in the s, carbamates in s and pyrethroids in s and the introduction of herbicides and fungicides in the s—s contributed greatly to pest control and agricultural output. Ideally a pesticide must be lethal to the targeted pests, but not to non-target species, including man.
Pesticides are widely used in agricultural production to prevent or control pests, diseases, weeds, and other plant pathogens in an effort to reduce or eliminate yield losses and maintain high product quality. Although pesticides are developed through very strict regulation processes to function with reasonable certainty and minimal impact on human health and the environment, serious concerns have been raised about health risks resulting from occupational exposure and from residues in food and drinking water.
Он совсем забыл про кольцо на пальце, забыл, для чего приехал в Севилью. Он посмотрел на приближающуюся фигуру, затем перевел взгляд на кольцо. Из-за чего погибла Меган. Неужели ему предстояло погибнуть по той же причине. Человек неумолимо приближался по крутой дорожке.
Беккер намеревался позвонить Сьюзан с борта самолета и все объяснить. Он подумал было попросить пилота радировать Стратмору, чтобы тот передал его послание Сьюзан, но не решился впутывать заместителя директора в их личные дела. Сам он трижды пытался связаться со Сьюзан - сначала с мобильника в самолете, но тот почему-то не работал, затем из автомата в аэропорту и еще раз - из морга. Сьюзан не было дома. Он не мог понять, куда она подевалась.
Камера, подрагивая, словно наехала на него, и кадр не сразу оказался в фокусе. А Смит тем временем безучастно продолжал свои комментарии: - Как вы видите, у Танкадо случился мгновенный сердечный приступ. Сьюзан стало дурно оттого, что она увидела. Танкадо прижал изуродованную руку к груди с выражением недоумения и ужаса на лице. - Вы можете заметить, - продолжал Смит, - что взгляд его устремлен. Он ни разу не посмотрел по сторонам.
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