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Detasseling
Detasseling corn is removing the pollen-producing flowers, the tassel, from the tops of corn (maize) plants and placing them on the ground. It is a form of pollination control, Iowa State University. Retrieved October 12, 2009. employed to cross-breed, or hybridize, two varieties of corn. Fields of corn that will be detasseled are planted with two varieties of corn. Removing the tassels from all the plants of one variety leaves the grain that is growing on those plants to be fertilized by the tassels of the other, resulting in a hybrid. In addition to being more physically uniform, hybrid corn produces dramatically higher yields than corn produced by open pollination. With modern seed corn, the varieties to hybridize are carefully ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterosis
Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions of its parents. The heterotic offspring often has traits that are more than the simple addition of the parents' traits, and can be explained by Mendelian or non-Mendelian inheritance. Typical heterotic/hybrid traits of interest in agriculture are higher yield, quicker maturity, stability, drought tolerance etc. Definitions In proposing the term heterosis to replace the older term heterozygosis, G.H. Shull aimed to avoid limiting the term to the effects that can be explained by heterozygosity in Mendelian inheritance. Heterosis is often discussed as the opposite of inbreeding depression, although differences in these two concepts can be seen in evolutionary considerations such as the role of genetic variation or the effects of genetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasmic Male Sterility
Cytoplasmic male sterility is total or partial male sterility in hermaphrodite organisms, as the result of specific nuclear and mitochondrial interactions. Male sterility is the failure to produce functional anthers, pollen, or male gametes. Such male sterility in hermaphrodite populations leads to gynodioecious populations (populations with coexisting fully functioning hermaphrodites and male-sterile hermaphrodites). Cytoplasmic male sterility, as the name indicates, is under extranuclear genetic control (under control of the mitochondrial or plastid genomes). It shows non-Mendelian inheritance, with male sterility inherited maternally. In general, there are two types of cytoplasm: N (normal) and aberrant S (sterile) cytoplasms. These types exhibit reciprocal differences. History Joseph Gottlieb Kölreuter was the first to document male sterility in plants. In the 18th century, he reported on anther abortion within species and specific hybrids. Cytoplasmic male sterility (CMS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corntassel 7095
Old Tassel — ''Reyetaeh'' in Cherokee language, ''Koatohee'', sometimes Corntassel (Cherokee language: ''Utsi'dsata'', died 1788) — was "First Beloved Man" (the equivalent of a regional Tribal chief, Cherokee chief) of the Overhill Cherokee after 1783, when the United States gained independence from Great Britain. He worked to try to keep the Cherokee people of the Overhill region out of the Cherokee–American wars being fought between the Frontier, European-American frontiersmen and the Chickamauga Cherokee, Chickamauga band warriors led by Dragging Canoe. He was murdered in 1788 along with another chief at Chilhowee (Cherokee town), Chilhowee and 5 others by Overmountain Men, white settlers John Kirk, John Sevier and others, under a flag of truce. Family Old Tassel's brothers were the warriors Pumpkin Boy and Doublehead. His maternal nephew was John Watts (Cherokee chief), John Watts, known as "Young Tassel." Known history Old Tassel became "First Beloved Man" of the Over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Child Labour
Child labour is the exploitation of children through any form of work that interferes with their ability to attend regular school, or is mentally, physically, socially and morally harmful. Such exploitation is prohibited by legislation worldwide, although these laws do not consider all work by children as child labour; exceptions include work by child artists, family duties, supervised training, and some forms of work undertaken by Amish children, as well as by Indigenous children in the Americas. Child labour has existed to varying extents throughout history. During the 19th and early 20th centuries, many children aged 5–14 from poorer families worked in Western nations and their colonies alike. These children mainly worked in agriculture, home-based assembly operations, factories, mining, and services such as news boys—some worked night shifts lasting 12 hours. With the rise of household income, availability of schools and passage of child labour laws, the inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybridisation (biology)
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different variety (botany), varieties, subspecies, species or genus, genera through sexual reproduction. Generally, it means that each cell has genetic material from two different organisms, whereas an individual where some cells are derived from a different organism is called a chimera (genetics), chimera. Hybrids are not always intermediates between their parents such as in blending inheritance (a now discredited theory in modern genetics by particulate inheritance), but can show Heterosis, hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductive isolation, reproductively isola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Wall Street Journal
''The Wall Street Journal'' (''WSJ''), also referred to simply as the ''Journal,'' is an American newspaper based in New York City. The newspaper provides extensive coverage of news, especially business and finance. It operates on a subscription model, requiring readers to pay for access to most of its articles and content. The ''Journal'' is published six days a week by Dow Jones & Company, a division of News Corp. As of 2023, ''The'' ''Wall Street Journal'' is the List of newspapers in the United States, largest newspaper in the United States by print circulation, with 609,650 print subscribers. It has 3.17 million digital subscribers, the second-most in the nation after ''The New York Times''. The newspaper is one of the United States' Newspaper of record, newspapers of record. The first issue of the newspaper was published on July 8, 1889. The Editorial board at The Wall Street Journal, editorial page of the ''Journal'' is typically center-right in its positio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roguing
In agriculture, roguing is the act of identifying and removing plants with undesirable characteristics from agricultural fields. Rogues are removed from the fields to preserve the quality of the crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. In other words, a crop is a plant or plant product that is grown for a specific purpose such as food, Fiber, fibre, or fuel. When plants of the same spe ... being grown. Plants being removed may be diseased, of an unwanted variety, or undesirable for other reasons. For example, to ensure that the crop retains its integrity in terms of certain physical attributes, such as color and shape, individual plants that exhibit differing traits may be removed. Roguing is particularly important when growing seed crops, to prevent plants with undesirable characteristics from propagating into subsequent generations.Agricultural Seed Production By Raymond A. T. George References Agricultural pests Agr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TEENAGE WORKER DETASSELING CORN IN A FIELD DURING THE SUMMER NEAR NEW ULM, MINNESOTA
Adolescence () is a transitional stage of human physical and psychological development that generally occurs during the period from puberty to adulthood (typically corresponding to the age of majority). Adolescence is usually associated with the teenage years, but its physical, psychological or cultural expressions may begin earlier or end later. Puberty typically begins during preadolescence, particularly in females. Physical growth (particularly in males) and cognitive development can extend past the teens. Age provides only a rough marker of adolescence, and scholars have not agreed upon a precise definition. Some definitions start as early as 10 and end as late as 30. The World Health Organization definition officially designates adolescence as the phase of life from ages 10 to 19. Biological development Puberty in general Puberty is a period of several years in which rapid physical growth and psychological changes occur, culminating in sexual maturity. The average age ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Harrison Shull
George Harrison Shull (April 15, 1874 – September 28, 1954) was an American plant geneticist and the younger brother of botanical illustrator and plant breeder J. Marion Shull. He was born on a farm in Clark County, Ohio, graduated from Antioch College in 1901 and from the University of Chicago ( Ph.D.) in 1904, served as botanical expert to the Bureau of Plant Industry in 1903–04, and thenceforth was a botanical investigator of the Carnegie Institution at the Station for Experimental Evolution, Cold Spring Harbor, N. Y., giving special attention to the results of Luther Burbank's work. Shull played an important role in the development of hybrid maize (in the USA, popularly 'corn') which had great impact upon global agriculture. As a geneticist, Shull worked with maize plants. He was interested in pure breeds not for their economic value but for his experiments in genetics. He produced maize breeds that bred true and then crossed these strains. The hybrid offspring of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen
Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male Conifer cone, cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it Germination, germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and Forensic science, forensics. Pollen in plants is used for transferring Ploidy#Haploid and monoploid, haploid male genetic ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
80-G-K-14241 - Yeoman Student De-tasseling Corn In Iowa (ca 1944)
8 (eight) is the natural number following 7 and preceding 9. Etymology English ''eight'', from Old English '', æhta'', Proto-Germanic ''*ahto'' is a direct continuation of Proto-Indo-European '' *oḱtṓ(w)-'', and as such cognate with Greek and Latin , both of which stems are reflected by the English prefix oct(o)-, as in the ordinal adjective ''octaval'' or ''octavary'', the distributive adjective is ''octonary''. The adjective ''octuple'' (Latin ) may also be used as a noun, meaning "a set of eight items"; the diminutive ''octuplet'' is mostly used to refer to eight siblings delivered in one birth. The Semitic numeral is based on a root ''*θmn-'', whence Akkadian ''smn-'', Arabic ''ṯmn-'', Hebrew ''šmn-'' etc. The Chinese numeral, written (Mandarin: ''bā''; Cantonese: ''baat''), is from Old Chinese ''*priāt-'', ultimately from Sino-Tibetan ''b-r-gyat'' or ''b-g-ryat'' which also yielded Tibetan '' brgyat''. It has been argued that, as the cardinal num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piece Rates
Piece work or piecework is any type of employment in which a worker is paid a fixed piece rate for each unit produced or action performed, regardless of time. Context When paying a worker, employers can use various methods and combinations of methods. Some of the most prevalent methods are: wage by the hour (known as "time work"); annual salary; salary plus commission (common in sales jobs); base salary or hourly wages plus gratuities (common in service industries); salary plus a possible bonus (used for some managerial or executive positions); salary plus stock options (used for some executives and in start-ups and some high tech firms); salary pool systems; gainsharing (also known as "profit sharing"); and being paid by the piece – the number of things they make, or tasks they complete (known as "output work"). Some industries where piece rate pay jobs are common are agricultural work, cable installation, call centers, writing, editing, translation, truck driving, data ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
