Around 1450 BC there was cultural activity near Bogotá, in "El Abra". In 1000 BC, groups of amerindians developed the political system of "cacicazgos" (answering to a figure known as the Cacique) with a pyramidal structure of power, especially in the cases of the Muisca or Chibcha people. They have been considered to have one of the most developed political systems in South America, after the Incas. Spanish explorers made the first exploration of the Caribbean littoral in 1500 led by Rodrigo de Bastidas. Christopher Columbus navigated near ...

See also:

Colombia, Colombia - History, Colombia - Politics, Colombia - Geography, Colombia - Departments, Colombia - Economy, Colombia - Demographics, Colombia - Religion, Colombia - Culture, Colombia - Miscellaneous topics

Read more here: » Colombia: Encyclopedia II - Colombia - History

Agriculture is the process of producing food, feed, fiber and other desired products by the cultivation of certain plants and the raising of domesticated animals (livestock). The practice of agriculture is also known as "farming", while scientists, inventors and others devoted to improving farming methods and implements are also said to be engaged in agriculture. More people in the world are involved in agriculture as their primary economic activity than in any other, yet it only accounts for four percent of the world's GDP.

• Agriculture - Overview
• Agriculture - History
• Agriculture - Crops
• Agriculture - Seed Testing
• Agriculture - World production of major crops in 2004
• Agriculture - Crop improvement
• Agriculture - Environmental problems
• Agriculture - Policy
• Agriculture - Agricultural Revolutions
• Agriculture - Methods

Read more here: » Agriculture: Encyclopedia - Agriculture

The 20th century lasted from 1901 to 2000 in the Gregorian calendar. Common usage sometimes regards it as lasting from 1900 to 1999. The 20th century is also sometimes known as the nineteen hundreds (1900s). However, a number of arguments have been used to justify the common usage. One advanced by Stephen Jay Gould is that the first decade had only nine years, thus contradicting the definition of decade equaled 10 years. Another argument is that the astronomical year numbering system for years does have a year zero, the ...

Including:

• 20th century - Overview
• 20th century - Important developments events and achievements
• 20th century - Science and technology
• 20th century - Wars and politics
• 20th century - Culture and entertainment
• 20th century - Disease and medicine
• 20th century - Natural resources and the environment
• 20th century - Significant people
• 20th century - World leaders
• 20th century - Scientists
• 20th century - Humanities
• 20th century - Business
• 20th century - Aerospace pioneers
• 20th century - Spiritual figures
• 20th century - Artists
• 20th century - Music
• 20th century - Film
• 20th century - Writers and poets
• 20th century - Sports figures
• 20th century - Decades and years

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20th century - World leaders. Africa Gnassingbe Eyadema, Togo Félix Houphouët-Boigny, Côte d'Ivoire Kenneth Kaunda, Zambia Jomo Kenyatta, Kenya Idi Amin, Uganda Nelson Mandela, South Africa Robert Mugabe, Zimbabwe Gamal Abdal Nasser, Egypt Kwame Nkrumah, Ghana Julius Nyerere, Tanzania Habib Bourguiba, Tunisia Muammar al-Qaddafi, Libya Haile Selassie, Ethiopia Léopold Sédar Sengh ...

See also:

20th century, 20th century - Overview, 20th century - Important developments events and achievements, 20th century - Science and technology, 20th century - Wars and politics, 20th century - Culture and entertainment, 20th century - Disease and medicine, 20th century - Natural resources and the environment, 20th century - Significant people, 20th century - World leaders, 20th century - Scientists, 20th century - Humanities, 20th century - Business, 20th century - Aerospace pioneers, 20th century - Spiritual figures, 20th century - Artists, 20th century - Music, 20th century - Film, 20th century - Writers and poets, 20th century - Sports figures, 20th century - Decades and years

Read more here: » 20th century: Encyclopedia II - 20th century - Significant people

Listed by brand name, generic name and length of residual toxicity. Note that the brand names listed here are by no means complete. Pesticide toxicity to bees - Carbamates. Baygon (propoxur) Furadan (carbofuran) ⇒ 7 - 14 days Lannate (methomyl) Lannate LS ⇒ 2 hours + Mesurol (methiocarb) Nudrin (methomy) Pesticide toxicity to bees - Organophosphates. Afugan (pyrazophos) Azodrin (mono ...

See also:

Pesticide toxicity to bees, Pesticide toxicity to bees - Classification of toxicity based on Lethal Dose 50% LD₅₀mg/bee, Pesticide toxicity to bees - Bee kill rate per hive, Pesticide toxicity to bees - Highly Toxic Pesticides to Bees, Pesticide toxicity to bees - Carbamates, Pesticide toxicity to bees - Organophosphates, Pesticide toxicity to bees - Synthetic pyrethroids, Pesticide toxicity to bees - Chlorinated cyclodienes, Pesticide toxicity to bees - Chloronicotines, Pesticide toxicity to bees - Herbicides, Pesticide toxicity to bees - Others, Pesticide toxicity to bees - Highly toxic and banned in the US, Pesticide toxicity to bees - Moderately toxic, Pesticide toxicity to bees - Relatively non-toxic, Pesticide toxicity to bees - Common insecticides toxic to bees used on soybeans

Read more here: » Pesticide toxicity to bees: Encyclopedia II - Pesticide toxicity to bees - Highly Toxic Pesticides to Bees

Agrichemical (or agrochemical), a contraction of agricultural chemical, is a generic term for the various chemical products used in agriculture. In most cases, agrichemical refers to the broad range of pesticides (e.g. insecticides, herbicides, fungicides), but it may also include synthetic fertilizers, hormones and other chemical growth agents, and concentrated stores of raw animal manure. Most agrichemicals are toxic, and all agrichemicals in bulk storage pose significant environmental and/o ...

Read more here: » Agrichemical: Encyclopedia - Agrichemical

Arsenic is a chemical element in the periodic table that has the symbol As and atomic number 33. This is a notoriously poisonous metalloid that has three allotropic forms; yellow, black and grey. Arsenic and its compounds are used as pesticides, herbicides, insecticides and various alloys. Arsenic - Notable characteristics. Arsenic is very similar chemically to its predecessor phosphorus, so much so that it will partly substitute for phosphorus in biochemical reactions and is thus poisonous. When hea ...

Including:

• Arsenic - Notable characteristics
• Arsenic - Applications
• Arsenic - History
• Arsenic - Occurrence
• Arsenic - Precautions
• Arsenic - Compounds
• Arsenic - Endnotes

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Aniline, phenylamine or aminobenzene (C6H5NH2) is an organic chemical compound which is a primary aromatic amine consisting of a benzene ring and an amino group. The chemical structure of aniline is shown at the right. Aniline - Synthesis. Aniline can be produced from benzene in two steps. First, benzene is nitrated (reacted with nitric acid, a form of electrophilic substitution reaction) to give nitrobenzene. Second, the nitrobenzene is reduced to give aniline ...

Including:

• Aniline - Synthesis
• Aniline - Properties
• Aniline - Uses
• Aniline - History
• Aniline - Toxicology

Read more here: » Aniline: Encyclopedia - Aniline

In agriculture and gardening, a beneficial organism is any animal, insect or other living organism, including microorganisms, that provides an advantage in the growing process. These services fall in three broad categories: pest control, pollination, and general soil maintenance. The opposite of beneficial organisms are pests, organisms that are deemed detrimental to the growing process. The distinction between beneficial and pest is arbitrary, subjectively determined by examining the effect of a particular organsim in a ...

Including:

• Beneficial organism - Beneficial organisms in agriculture

Read more here: » Beneficial organism: Encyclopedia - Beneficial organism

Chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), post-viral fatigue syndrome (PVFS) and various other names, is a syndrome of unknown and possibly multiple etiology, affecting the central nervous system (CNS), immune, and many other systems and organs. Most definitions other than the 1991 UK "Oxford", require a number of features, the most common being severe mental and physical depletion, which according to the 1994 Fukuda definition is "unrelieved by rest", and is usually made worse by even trivial exertion (controver ...

Including:

• Chronic fatigue syndrome - History
• Chronic fatigue syndrome - Nomenclature
• Chronic fatigue syndrome - Symptoms
• Chronic fatigue syndrome - Course
• Chronic fatigue syndrome - Onset
• Chronic fatigue syndrome - Activity levels
• Chronic fatigue syndrome - Post-exertion symptom exacerbation
• Chronic fatigue syndrome - Duration
• Chronic fatigue syndrome - Diagnosis
• Chronic fatigue syndrome - CDC 1994 criteria aka Fukuda
• Chronic fatigue syndrome - Other systems
• Chronic fatigue syndrome - Controversies
• Chronic fatigue syndrome - Epidemiology
• Chronic fatigue syndrome - Disease associations
• Chronic fatigue syndrome - Co-morbidity
• Chronic fatigue syndrome - Proposed etiologies and corresponding treatments
• Chronic fatigue syndrome - Allergies
• Chronic fatigue syndrome - Autonomic nervous system disruption
• Chronic fatigue syndrome - Damage to ascending reticular activating system
• Chronic fatigue syndrome - Depression
• Chronic fatigue syndrome - Hormonal dysfunction
• Chronic fatigue syndrome - Immune dysfunction
• Chronic fatigue syndrome - Infectious agents
• Chronic fatigue syndrome - Inner-ear disorders
• Chronic fatigue syndrome - Metabolic disorders
• Chronic fatigue syndrome - Nutritional deficiency or imbalance
• Chronic fatigue syndrome - Psychosomatic causes
• Chronic fatigue syndrome - Spinal problems
• Chronic fatigue syndrome - Toxic agents
• Chronic fatigue syndrome - Other treatments
• Chronic fatigue syndrome - Social issues
• Chronic fatigue syndrome - Notable sufferers

Read more here: » Chronic fatigue syndrome: Encyclopedia - Chronic fatigue syndrome

This article is about the chemical element. For the article about Phosphorus meaning "morning star", go to Phosphorus (morning star). Phosphorus, (from the Greek language phôs meaning "light", and phoros meaning "bearer"), is the chemical element in the periodic table that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate rocks and in all living cells. Due to its high reactivity, it is never found as a free elemen ...

Including:

• Phosphorus - Notable characteristics
• Phosphorus - Forms
• Phosphorus - Applications
• Phosphorus - Biological role
• Phosphorus - History
• Phosphorus - Occurrence
• Phosphorus - Precautions
• Phosphorus - Isotopes
• Phosphorus - Spelling
• Phosphorus - Compounds

Read more here: » Phosphorus: Encyclopedia - Phosphorus

T. aestivum T. aethiopicum T. araraticum T. boeoticum T. carthlicum T. compactum T. dicoccon T. durum T. ispahanicum T. karamyschevii T. militinae T. monococcum T. polonicum T. spelta T. timopheevii T. trunciale T. turanicum T. turgidum T. urartu T. vavilovii T. zhukovskyi References:
Including:

• Wheat - History
• Wheat - Genetics & Breeding
• Wheat - Hulled vs. free-threshing wheat
• Wheat - Naming
• Wheat - Major cultivated species of wheat
• Wheat - Economics
• Wheat - Production and consumption statistics
• Wheat - Agronomy
• Wheat - Crop development
• Wheat - Wheat stages
• Wheat - Diseases
• Wheat - Pests
• Wheat - Wheat in the United States

Read more here: » Wheat: Encyclopedia - Wheat

Chloracne is an acne-like eruption of blackheads, cysts, and pustules associated with over-exposure to certain halogenic aromatic hydrocarbons, such as chlorinated dioxins and dibenzofurans. The lesions are most frequently found on the cheeks, behind the ears, in the armpits and groin region. The condition was first described in German industrial workers in 1897 by Von Bettman, and was initially believed to be caused by exposure to toxic chlorine (hence the name "chloracne"). It was only in the mid-1950s that chloracne was associated with aromatic hydrocarbons[1]. The substances that may cause chloracn ...

Including:

• Chloracne - Etiology and progression
• Chloracne - Treatment
• Chloracne - Related conditions
• Chloracne - Notable cases

Read more here: » Chloracne: Encyclopedia - Chloracne

Weed is the generic word for a plant growing in a spot where it is not wanted. Weeds become of economic significance in connection with farming, where their presence may result in reduced crop yield when growing in fields and poison domesticated animals when growing on pasture land. Many weeds are short-lived annual plants, that normally take advantage of temporarily bare soil to produce another generation of seeds before the soil is covered over again by slower growth; with the advent of agriculture, with extensive areas of ploughed soil exposed every year, the opportuni ...

Including:

• Weed - Invasive species
• Weed - Weed control
• Weed - Plants that are often considered weeds

Read more here: » Weed: Encyclopedia - Weed

Urushiol-induced contact dermatitis (also Toxicodendron dermatitis and Rhus dermatitis) is the medical name given to allergic rashes produced by urushiol oil contained in various plants. This includes the genus Toxicodendron (including poison-ivy, poison-oak, and poison sumac), as well as other plants in the family Anacardiaceae (mango, Rengas tree, Burmese lacquer tree, India marking nut tree, and the shell o ...

Including:

• Urushiol-induced contact dermatitis - Mechanism
• Urushiol-induced contact dermatitis - Prevention
• Urushiol-induced contact dermatitis - First aid
• Urushiol-induced contact dermatitis - Treatment
• Urushiol-induced contact dermatitis - Cure
• Urushiol-induced contact dermatitis - Common Myths

Read more here: » Urushiol-induced contact dermatitis: Encyclopedia - Urushiol-induced contact dermatitis

Urbanization is the expansion of a city or metropolitan area, namely the proportion of total population or area in urban localities or areas (cities and towns), or the increase of this proportion over time. It can thus represent a level of urban population relative to total population of the area, or the rate at which the urban proportion is increasing. Both can be expressed in percentage terms, the rate of change expressed as a perc ...

Including:

• Urbanization - Economic effects
• Urbanization - Ecological and environmental effects
• Urbanization - Psychological effects and urban lifestyle
• Urbanization - Changing form of urbanization
• Urbanization - Examples

Read more here: » Urbanization: Encyclopedia - Urbanization

Tillage, or cultivation (a term which also has broader meanings related to the raising of plants in general) is the agricultural preparation of the soil to receive seeds. Primary tillage loosens the soil and mixes in fertilizer and/or plant material, resulting in soil with a rough texture. Secondary tillage produces finer soil and sometimes shapes the rows. It can be done by a using various combinations of equipment: plow, disk plow, harrow, dibble, hoe, rotary tillers, subsoiler, ridge or bed forming tillers, roller. ...

Read more here: » Tillage: Encyclopedia - Tillage

Weed control, a botanical component of pest control, stops weeds from reaching a mature stage of growth when they could be harmful to domesticated plants, sometimes livestocks, by using manual techniques including soil cultivation, mulching and herbicides. Prevention of weeds from growing is desirable, but often difficult to achieve, due to the resilient fertilization and growth patterns of weeds. Weed control - The effects of weeds on other plants. Luther Burbank has been quoted as the source of the saying ...

Including:

• Weed control - The effects of weeds on other plants
• Weed control - Methods
• Weed control - Stale seed bed technique
• Weed control - Use of herbicides
• Weed control - Wood
• Weed control - UK Legislation concerning weeds
• Weed control - Homemade Weed Killer Recipe
• Weed control - External link
• Weed control - Reference

Read more here: » Weed control: Encyclopedia - Weed control

 - Total (2003)  - Density 44,531,434 36/km²  - Declared  - Recognised July 20, 1810 August 7, 1819 The Republic of Colombia is a country in northwestern South America. It is bordered to the north and north-west by the Caribbean Sea, to the east by Venezuela and Brazil, to the south by Ecuador and Peru, and to the west by Panama and the Pacific Ocean. Colombia - History. Main article: History of ...

Including:

• Colombia - History
• Colombia - Politics
• Colombia - Geography
• Colombia - Departments
• Colombia - Economy
• Colombia - Demographics
• Colombia - Religion
• Colombia - Culture
• Colombia - Miscellaneous topics

Read more here: » Colombia: Encyclopedia - Colombia

Biological warfare, also known as germ warfare, is the use of any organism (bacteria, virus or other disease-causing organism) or toxin found in nature, as a weapon of war. It is meant to incapacitate or kill an adversary. The creation and stockpiling of biological weapons is outlawed by the 1972 Biological Weapons Convention, signed by over 100 states, because a successful attack could conceivably result in thousands, possibly even millions, of deaths and could cause severe disruptions to societies and economies. Oddly ...

Including:

• Biological warfare - History
• Biological warfare - Biological weapons characteristics
• Biological warfare - Attacking Crops & Animals
• Biological warfare - Protective measures
• Biological warfare - The role of public health departments and disease surveillance
• Biological warfare - Examples of biological warfare
• Biological warfare - 1984 Rajneeshee salmonella attack
• Biological warfare - 2001 anthrax attack

Read more here: » Biological warfare: Encyclopedia - Biological warfare