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Define terms to be used throughout the site a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 Click one of the letters above to be taken to a page of all terms beginning with that letter.
a - abaxial
- Located on the side away from the axis (e.g., the undersurface of a leaf).
- abiotic
- Nonliving components of the environment, such as water, solar radiation, oxygen, organic compounds, and soil nutrients.
- abomasum
- The fourth compartment of the ruminant stomach, comprising the true stomach, in which occur digestive processes similar to those found in the nonruminant stomach.
- acceptability
- Readiness with which animals select and ingest a forage; sometimes used interchangeable to mean either palatability or voluntary intake.
- acid detergent fiber
- Insoluble residue following extraction of herbage with acid detergent (ban Soest); cell wall constituents minus hemicellulose.Synonyms: ADF
- acid detergent fiber digestibility
- The digestibility of acid detergent fiber (ADF) of a forage, as determined by the percentage decrease in ADF measured before and after in vitro or in vivo digestion
- acid detergent lignin
- Lignin in the residue determined following extraction with acid detergent.Synonyms: ADL
- acid pepsin
- Used is second stage of in vitro forage digestion, 2 g of 0.1 g kg-1 pepsin in 1 L of 0.1 M HCI.
- ad libitum feeding
- Daily feed offerings that allow free-will consumption, generally fed to have a daily excess of 15% of feed remaining.
- adaxial
- Located on the side toward the axis (e.g., the upper surface of a leaf).
- adventitious roots
- The second root system which develops from the lower nodes of each grass tiller; seminal roots, the primary roots, develop from embryo primordia but are short lived.
- aerobic
- Pertaining to life or processes occurring in free oxygen or in oxygen concentrations normal in air (21% O2). See also anaerobic
- aflatoxin C17H10O6
- A polynuclear substance derived from molds; a known carcinogen. It is produced by a fungus occurring on peanuts, corn , and other plants, especially seeds.
- aftermath
- Residue and/or regrowth of plants (forage) used for grazing after harvesting of a crop.
- agro-silvo-pastoral
- Land use system in which woody perennials are grown with agricultural crops, forage crops, and livestock production.
- agroforestry
- Land use system in which woody perennials are grown for wood production in association with agricultural crops, with or without animal production, or other commercial enterprises.
- agrostology
- agrostology
Study of grasses; their classification, management, and utilization.
- alkaloid
- One of a class of basic organic compounds with nitrogen in their structure; a secondary product of plant metabolism. An example is perloline, produced by tall fescue.
- allelopathy
- The positive or negative influence of living plant upon another due to secretion of chemical substances. See autotoxicity.
- amylopectin
- The form of starch in which branching occurs through alpha 1-6 linkages from an amylose backbone. Amylopectins are more easily dissolved and digested than amylose. The contents of amylose and amylopectins in seed grains are genetically controlled.
- amylose
- amylose
The form of starch in which linkages are exclusively alpha 1-4. While representative formulas usually are presented in a linear fashion, the molecules actually have a spiral form.
- anaerobic
- anaerobic
Living in the absence of free oxygen; the opposite of aerobic.
- annual
- annual
A plant that completes its life cycle and dies within a year.
- anoxia
- Oxygen deficiency.
- anthesis
- Stage in floral development when pollen is shed from anthers. With self-pollinating species, anthesis occurs prior to the seapration of the lemma and palea.
- antiquality constituents
- Constituents that have negative effects on forage intake or that produce negative responses in animals consuming the produce containing the constituent.
- apical dominance
- Inhibiting effect of a terminal bud upon the development of lateral buds.
- apomixis
- Formation of viable embryos without actual union of male and female gametes, as in Kentucky bluegrass.
- ash
- The residue remaining after complete burning of combustible matter; consists mainly of minerals in oxidized form.
- auricle
- A leaf appendage; adjacent to the collar between the blade and the sheath, a claw-like lobe at the base of leaf blades of certain grass species.
- autotoxicity
- A specific type of allelopathy where the presence of adult plants interferes with the germination and development of its own seedlings.
- awn
- A stiff bristle. Used in the Asteraceae for a pappus of stout bristles or hard needle-like structures. Used in the Poaceae for the bristley appendages often borne on glumes and lemmas. Sometimes called a beard.
- awned
- Having an awn.
- awnless
- Not having an awn.
- axillary bud
- Meristematic apex located in the junction of the leaf and stem; gives rise to tillers in grasses and to branches and flowers in dicots.
- axis
- The middle of the structure (e.g., the rachis of a compound leaf, the center of a compound ovary).
b - bioassay
- The use of living organisms to quantitatively estimate the amount of biologically active substances present in a sample.
- biomass
- The weight of living organisms (plants and animals) in an ecosystem at a given point in time, expressed either as fresh or dry weight.
- blade
- The part of a leaf of a grass or similar plant above the sheath, also known as the lamina.
- bloat
- Excessive accumulation of gases in the rumen of animals because loss through the esophagus is impaired, causing distension of the rumen.
- bloom, early
- Initial flowering (anthesis) in the uppermost portion of the inflorescence.Synonyms: early bloom
- bloom, full
- Essentially all florets in the inflorescence in anthesis.Synonyms: full bloom
- blooming
- Refers to anthesis in the grass family, or to the period during which florets are open and anthers are extended.
- BNF
- biological nitrogen fixation
- boot stage
- Growth stage when a grass inflorescence is enclosed by the sheath of the uppermost leaf.
- bract
- A modified or reduced leaf subtending a flower or inflorescence such as the glumes and lemmas.
- brassica
- Important species of brassica fall into three groups: turnips, B. rapa L., include common root crops and some rapes with turnip-like leaves; swedes, B. napus L., include not only the swedes proper but the common or oil bearing rapes; and cabbages, B. oleracea L., include the common vegetable and also the forage crops thousand-headed kale and marrowstem kale.
- brown patch
- brown patch
Latin name Pellicularia filamentosa (Pat.) Rogers.
c - C3-plant
- a plant employing ribulose bisphosphate carboxylase as the primary CO2-capturing enzyme, with the first product being a 3-carbon acid, also display photorespiration.
- C4-plant
- a plant employing phosphoenolpyruvate carboxylase as the primary CO2-capturing enzyme, with the first product being a 4-carbon acid, does not display photorespiration.
- calorie (gram calorie)
- The amount of heat required to raise the temperature of 1g of water one degree Celsius. One kilocalorie (kcal) = 1,000 calories; one megacalorie (Mcal) = 1,000,000 calories.
- canopy
- canopy
The aerial portion of plants in their natural growth position; usually expressed as percent of ground so occupied or as leaf area index.
- carbohydrate
- Compound of carbon, hydrogen, and oxygen in the ratio of CH2O, as in sugar, starch, and cellulose.
- carbohydrates, nonstructural
- Soluble carbohydrates found in the cell contents, as contrasted with structural carbohydrates in the cell walls. Assumed to be available to support life processes.
- carbohydrates, structural
- Carbohydrates found in the cell walls (e.g. hemicellulose, cellulose); assumed to not be available to support life processes.
- caryopsis
- Small, one-seeded, dry fruit with a thin pericarp surrounding and adhering to the seed; the ripened fruit of grasses, a single seed or kernel of grain.
- cecum
- Intestinal pouch located at the junction of larger and small intestines of non-ruminants. Functions somewhat similar to a rumen. Usually it is much larger in the hebivorous horse than in the nonherbivorous monogastrics.
- cell wall constituents
- Compounds that make up or constitute the cell wall, including cellulose, hemicellulose, lignin, and minerals (ash).
- cell wall content
- The proportion of plant material made up of cell walls as opposed to cell contents, usually determined by solubility differential.
- cellulase
- Enzymes that digest cellulose to hexose units.
- cellulose
- A carbohydrate formed from glucose that is linked by beta 1, 4 bounds, a major constituent of plant cell walls. a colorless solid; insoluble in water.
- certified
- Meeting a specified standard.
- climatologist
- One versed in, or who studies, climatology.
- climatology
- The meteorological study of climates and their phenomena
- coated seed
- Seed for planting purposes to which a substantial amount of foreign material is used to cover each seed to make the seed uniform in size and shape and free-flowing, or to serve as a carrier of fertilizer, pesticides, nitrogen-fixing microorganisms, coloring, or other additives. Synonym: pelleted seed.
- collar
- A thin band of meristematic tissue at the junction of the leaf blade and sheath in grasses.
- coloration
- Arrangement of colors.
- companion crop
- A crop such as a small grain that is sown with another crop, especially one that will emerge and develop slowly, such as a forage crop. Preferred to the term nurse crop.
- concentrate
- All feed, low in fiber and high in total digestible nutrients, that supplies primary nutrients (protein, carbohydrate, and fat); for example, grains, cottonseed meal, wheat bran.
- continuous stocking
- A method of grazing livestock on a given unit of land where animals have unrestricted and uninterrupted access throughout the time period when grazing is allowed. Usage: Specify the length of the grazing period.
- cool-season grass
- Grass species that grow best during cool, moist periods of the year; they commonly have temperature optimums of 15 to 25'C (59 to 77'F.)
- coumarin
- A white, crystalline compound with a vanilla-like odor that gives sweetclover its characteristic odor. An antiquality component of sweetclover.
- coumestrol
- Estrogenic factor occurring naturally in forage crops, especially in ladino clover, strawberry clover, and alfalfa.
- crimped
- Rolled with corrugated rollers, especially fresh forage, to break stems and facilitate drying.
- crown
- Base or stem where roots arise.
- crown rust
- Latin name Puccinia coronata Cda.
- crude fiber
- Coarse, fibrous portions of plants, such as cellulose, that are partially digestible and relatively low in nutritional value. In chemical analysis, it is the residue obtained after boiling plant material with dilute acid and then with dilute alkali. Term is being replaced with more specific NDF (neutral detergent fiber) and ADF (acid detergent fiber). Coarse, fibrous portions of plants, such as cellulose, that are partially digestible and relatively low in nutritional value. In chemical analysis, it is the residue obtained after boiling plant material with dilute acid and then with dilute alkali. Term is being replaced with more specific NDF (neutral detergent fiber) and ADF (acid detergent fiber). Coarse, fibrous portions of plants, such as cellulose, that are partially digestible and relatively low in nutritional value. In chemical analysis, it is the residue obtained after boiling plant material with dilute acid and then with dilute alkali. Term is being replaced with more specific NDF (neutral detergent fiber) and ADF (acid detergent fiber).
- cubing
- Process of forming hay into high-density cubes to facilitate transportation, storage, and feeding.
- culm
- The central axis of the flowering shoot of grasses, comprised of distinct nodes and internodes, each node bearing a leaf. The upper-most culm internode supporting the seed head is called the peduncle.
- cultivar
- (1) A variety, strain, or race that has originated and persisted under cultivation or was specifically developed for the purpose of cultivation. (2) For cultivated plants, the equivalent of botanical variety, in accordance with the International Code of Nomenclature of Cultivated Plants--1980.
- cuticle
- a waxy layer secreted by epidermal cells on the outer surface on plants.
- cutin
- A way layer secreted by epidermal cells on the outer surface on plants.
- cyanogenesis
- The release of hydrocyanic acid (HCN) in the process of chemical change. Cyanogenetic is the adjective form.
d - decapitation
- Untimely defoliation of a developing flowering culm in a manner which removes the shoot primordium.
- denuding
- Defoliation which severes a grass shoot above the developing floral bud (growing point) but beneath the collar zone of a majority of the exposed leaf blades.
- desiccant
- A drying agent
- digestibility (apparent)
- apparent: Digestibility determined by animal feeding trials, calculated as feed consumption minus excretion (feces), expressed as percent; does not account for endogenous excretions in the feces.
- digestibility (true)
- true: Actual digestiblity or availablility of feed, forage. or nutrient as represented by the balance between intake and fecal loss of the same ingested material with endogenous excretions in feces accounted for; in vitro digestibility without adjustment to in vivo base.
- diploid
- A tissue or plant with two sets of chromosomes in each cell (characterestic of sporphytes).
- dough stage
- Seed development stage at which endosperm development is pliable, like dough (e.g., soft, medium, hard); usually used when 50% of seeds on an inflorescence are in this stage of development.
- dry matter (DM)
- The substance in a plant remaining after oven drying to constant weight at a temperature slightly above the boiling point of water.
e - early bloom
- Initial flowering (anthesis) in the uppermost portion of the inflorescence.Synonyms: bloom, early
f - Frequently Asked Questions
- full bloom
- Essentially all florets in the inflorescence in anthesis.Synonyms: bloom, full
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