Agrochemicals means chemical products used in agriculture. In most cases agrochemicals refers to the broad range of pesticides including, insecticides, herbicides,fungicides and nematocides. It may also include synthetic fertilizers, hormones and other chemical growth agents and concentrated stores of raw animal manure.
Agrochemicals are looked upon as a vehicle for improved crop production technology through it is a costly input, balance use, optium does, correct method and right time of application of agrochemicals ensure increased crop production.
The requirement of fertilizers and pesticides for crops differ according to soil and meterolgy. A lot of agrochemical research is directed towards the introduction of genes that may provide disease or viral resistance into plants or other organisms.
Present-day chemical and mechanical agriculture is skillful planting on biolgically inactive and physically deteriorated soils. It is an expensive technology which regards soil only as ''support for fertilizers, plants and irrigation water. However crops are responding less and less to the chemical inputs (fertilizers and toxic chemicals), and to be able to afford them, farmers need government aid(i.e subsidies), which increase the debt of farmers and countries.
Precautions Using Agrochemicals:
Many agrochemicals are toxic and agrochemicals in bulk storage may pose significant environmental and/or health risks,particularly in the event of accidental spills. In many countries, use of approved agrochemicals may be required.
Government issued permits for purchase and use of approved agrochemicals may be required. Significant penalties can result from misuse, including improper storage resulting in spillage. On farms, proper storage facilities and labelling, emergency clean-up equipment and procedures and safety equipment and procedures for handling, application and disposal are often subject to mandatory standards and regulations.
Scope of Agrochemicals:
Todays progress in agriculture, science and technology make it possible for India to achieve its current level of scientific and technological excellence and it's high standard of living. The great challenge facing mankind in the 21st century is to produce basi necessities of food, feed, fibre and fuel.
One of the factors to meet these requirements to some extent is to improve the agricultural yield. Chemistry plays a vital role in the development of agriculture. Agrochemicals are looked upon as a vehicle for improved crop production technology through it is a costly input.
India is the fourth largest producer of agrochemicals globally, after United State, Japan and China. The agrochemicals industry is a significant industry for the Indian economy.
1) Pesticides:
The term pesticides is derived from two words, Caedo to kill or destroy pest, a harmful organisms. Hence pesticide is any agent that has capacity to kill or prevent pests from its attack.
Examples: DDT, BHC, Malathion, Parathion, 2,4-D etc.
** Classification of Pesticides:
A) Insecticides:
The word insecticide is derived from the Latin word 'Insectum' means cut into, and 'coedere' means to kill. Thus, it is an agent which kills insects.
Chemicals used to control damage or annoyances from insects by poisoning them through ingestion of stomach poisons by contact with the cuticle (the outer of the skin) or by fumigant action through the air.
Examples: Endosulfan, nicotinoids, rotenoids, lead arsenale, aldrin etc.
B) Herbicides:
Herbicides is a chemical compound used to control or destroy unwanted plants. Herbicides are sometimes called weed killers. Selectively, herbicides remove certain weeds from certain crops. The selectivity is not absoulte, but it is governed by the amount of chemical substance applied, the way it is applied, the degree of wetting of the filliage etc.
Examples: 2,4-D, dalapon, paraquat, butacarb, bantene, alachlor, sulphonyl urea etc.
C) Fungicides:
Fungicides are biocidal chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungi can cause serious damage in agriculture, resulting in critical losses at yield, quantity and profit. Fungicides are used in both agriculture and to fight fungal infections in animals.
It is a chemical substance used to kill growth called fungi that are harmful to human beings and plants. Diseases caused by fungi can destroy or seriously damage food crops.
Examples: Bordeaux mixture, copper oxychloride, sulphur compounds, formaldehyde, chlorine, benzomyl, zineb, dithiocarbamate etc.
D) Rotenticides:
Rotenticides, colloquially rat poison, are pest control chemicals intended to kill rodents (animals like rats, mice, rabbits, which cut things with its strong front teeth). Rotenticides are controversial, due to secondary poisoning and their risk to children, pets and wild life.
Metal phosphides have been used as means of killing rodents and are considered single-dose fast acting rotenticides (death occurs commonly within 1-3 days after single bait ingestion).
Examples: Warfarin, Sodium monofluroacetate, zinc phosphide etc.
Pesticide Formulations:
Pesticide active ingredient by themselves may not mix well with water, may be chemically unstable, may be difficult to handle or store, and may be difficult to apply for good pest control. To make an active ingredient useful, manufacturer add other ingredients to "formulate" the pesticide into the final product offered for sale.
Applications of Agrochemicals:
* Farmers and gardener use agrochemicals to grow bigger fruits, bigger vegetables and brighter flower blooms.
* Fertilizers agrochemicals inject much needed nutrient. Chemicals, such as nitrogen or potassium, directly into the soil to help plants grow.
* Different types of herbicides kill unnecessary weeds, allowing only the plant of choice to grow without competition for food.
* Pesticides applied periodically also make the plant poisonous to insects and other creatures that attempt to eat the leaves or fruit.
* Growth regulators and stimulates must be brought in line with the amounts and selection to increase the crop yield.