Pesticides

A pesticide is a chemical substance or a mixture of substances used to destroy, control or repel pests. Pests are the type of organisms that destroy plant growth or ruin the plant by eating it. A wide variety of pests can destroy agricultural crops and result in severe financial loss. Some examples of pests are insects, rodents, fungi, slugs and snails, bird mites, and weeds.

Brief History

The practice of agriculture has remained an essential part of human civilization. So, was the attack on crops by different kinds of organisms. Sumerians are supposed to be the pioneers in using sulphur as pesticide more than 4000 years ago. Production of synthetic pesticides increased in the 1940s when the function of chemicals like DDT, BHC, aldrin, dieldrin, captan, 2,4-D etc were studied and applied. DDT was widely used due to its pesticidal action over a wide range of organisms. being effective and inexpensive, many more pesticides were manufactured on a large scale.

Definition of Pesticides

Pesticides are those substances that help to repel, or control certain organisms that are harmful to plants.

Examples of Pesticides 

Numerous examples have been cited as examples of pesticides. They are insecticides, fungicides, larvicides, rodenticides, molluscicides etc.

Types of Pesticides

Pesticides are classified on the basis of their chemical structure, mode of action, formulation, persistence and the pests that they target. Some examples are given along with the products used.

On the Basis of the Target Group, Pesticides are Classified as:

• Insecticides: such as Allethrin, Boric acid, Cypermethrin, Malathion, etc to kill insects

• Fungicides: such as Pentachlorophenol to kill various kinds of fungi but also for mould and mildew

• Herbicides: such as 2,4-D are for plants that can act like pests such as weeds

• Larvicides: such as Teknar to attack larvae

• Rodenticides: such as Rozol, Rodent cake, Warfarin for rodents such as gophers, mice and rats

• Algaecides: to kill or inhibit the growth of algae

• Molluscicides: such as metaldehyde to control snails, slugs and other molluscs that can attack plants

Some other types of pesticides used for specific purposes include the desiccants, foggers, mothballs, repellants etc.

On the Basis of Chemical Structure, Pesticides are Grouped into:

• Chlorinated hydrocarbon, for example, Kelthane

• Carbamate, for example, Sevin

• Organophosphates, for example, Basudin

• Pyrethroids, for example, Decis

On the Basis of Mode of Action, Pesticides are Categorised for:

• Direct Application – These insecticides are dusted or sprayed and eliminate insects when they come in contact

• Control as Plant Food – These insecticides are consumed by the plant and eliminate insects when they eat the affected plants

• Fumigants – These insecticides are toxic fumes that destroy insects when inhaled

• Selective Herbicides – These herbicides destroy small seeds and weeds but not the plant, for example, Gesagard

On the Basis of Formulation, Pesticides are Classified into the Following Types:

• Dust forms of pesticide is prepared as dry small particles

• Granular form of pesticide is prepared as large dry particles

• Wettable powders of pesticides are prepared with finely distributed particles with other substances that helps the powder to be mixed with water to make a stable solution or suspension

• Dry bait pesticides, which are mixed with pest food to form dry pellets that will be eaten by pests

• Emulsifiable concentrate, which is used to dissolve a pesticide in an organic solvent to make an emulsifier

• Pheromones are active chemicals used to interfere with the mating behaviour of certain insects, thereby inhibiting their growth. 

• Wood preservatives are used for making wood more resistant to fungus and insects.

Benefits of Pesticides

Pesticides are helpful in keeping costs low as farmers are able to grow more food on the same field. Growing organic vegetables needs more investment due to hand weeding as compared to vegetables that are grown with herbicides.

Pesticides help to reduce waterborne diseases and those transmitted by insects. It helps to prevent the spread of diseases born from insects and rodents. 

Pesticides are used to preserve and protect the environment as it can help to reduce deforestation, soil erosion, and aid in conservation of natural resources.

The use of pesticides can help to improve the crop yield and subsequently increase the farmer’s income. It will improve farmer’s living standards and quality of life.

Pesticides help farmers save precious time by keeping the crop safe from weed instead of spending hours removing the weeds around their crops. When their crop is safe from pests, farmers need not till the land again and again in an attempt to grow their crops.

Pesticides transformed developing countries such as India into food producers. Crop protection helps farmers protect their crops and provide a bumper yield to the population.

Pesticides give food products a long and viable shelf life in the storage chambers or warehouses. They also help to prevent heavy post-harvest losses incurred due to plant diseases and pests and protect the good to eat safely.

Effect of Pesticides

Pesticides have several effects on our environment, health and even inside our house. These effects can be enlisted as the following:

Environmental Effects

Chemical pesticides are responsible for polluting our environment while being used in the field. Although their effects are short lived, they may begin causing hazardous environmental and health problems if they persist in the environment. When chemical pesticides are sprayed on the crops, they may spread to regions beyond the intended area.  

Effect on Crops and Soil

Pesticides degrade the quality of soil and further the quality of the food and yield. Chemical pesticides deplete the nutritional value of the food and contaminate it. When we eat any food such as apple, lettuce, potatoes or strawberries, these pesticides enter our body and may lead to many health issues. While these chemical pesticides are developed to kill organisms found on the crop, these are also harmful to other living things.

Health Effects

Exposure to various pesticides can cause short-term health problems (acute) as well as long-term diseases (chronic). Acute effects include rashes, nausea, diarrhoea, dizziness, breathing problems, eye irritation, etc. Chronic effects can cause birth defects, cancers, neurological harm, reproductive harm, etc. It can take months or even years before symptoms of chronic health problems manifest.

Use of Pesticides

Pesticides and insecticides are used by farmers or protecting crops from insects and worms.The land is limited and in order to meet the demands of food production farmers try to get more crops which are not infected .They tend to use pesticides for good yield but indie process the soil starts losing it's fertility.Due to all these aspects farmers use pesticides and insecticides.They also use this because to Safeguard human health, by stopping food crops from being infected by fungi.

To increase crop production, farmers have expanded the use of pesticides and fertilizers to meet the government's food sufficiency targets. Nowadays farmers fully rely on pesticides for increasing global agricultural productivity and conserving plantations from varying rent insects, pests, and diseases.

Reasons Farmers Use More Pesticides

• Pesticides help farmers to produce more yield with less land. 

• Pesticides assure huge harvests. 

• Pesticides help keep food cheap. 

• Pesticides help to reduce waterborne and insect-transmitted disease

• No hardship of hand weeding.

• More produce is limited.

How is Organic Farming more Effective?

In the present flourishing food environment,one of the most used words is organic which is actually why it needs to be redefined about organic fruits and vegetables. The initial phase towards this part is making high quality and premium organic vegetables and fruits for the population. Though they are really costly and not very attractive to look at, they have high nutritional effects as they are free from the effects of pesticides.

Nowadays people want to get good quality of food without the use of lot of pesticides and insecticides as they cause the tremendous effect to their health. that is why in today's context some farmers are shifting their cultivation from modern farming to organic farming .there are certain limitations for organic farming but still, some farmers are trying to implement these type of farming in their fields so that the soil retains its fertility in a long process. because of excess use of fertilizers, pesticides and insecticides, the topsoil becomes highly toxic and turn barren giving less yield.

Organic farming produces various products not only food grains and pulses but they are also producing fruits, vegetables, spices and also dairy products. They are also producing products like soaps, shampoos, processed foods, juices and jams and also dry fruits. Hence organic farming is slowly having an impact on a particular section of our economy

Even organic products have their own setbacks.

• "Organic" is the description for products that were not processed and yielded through chemical-free fertilizers and pesticides.

•  Organic products are usually more expensive as compared to other ones.

• it usually takes more effort and finances to maintain organic farms