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Pomology Glossary


A Soil Horizon

The A horizon is very top layer of the mineral soil. It lies just below the O horizon layer and has some amount of humus in it and can tend to be darker than the layers below. The soil particles in this zone are smaller and finer compared to the lower horizons of the soil. This is layer where seeds germinate and roots grow. Soil organisms, like earthworms, fungi, and bacteria, are mainly concentrated in this layer. It is often referred to as the 'biomantle', because most of the biological activities take place in this layer.


Abiotic factors are non-living factors in an ecosystem. As part of the ecosystem, these factors do affect the living things in it, but they are not living themselves. Examples are water, humidity, rain, elevation, salinity, pollution or radiation. Abiotic factors cause the variation one sees between different ecosystems.


Abscission is the shedding of various parts of an organism, such as a plant dropping a leaf, fruit, flower, or seed.

Abscisic Acid

Abscisic Acid is a plant hormone which promotes leaf detachment, induces seed and bud dormancy, and inhibits germination.


Acclimization is the process or result of becoming accustomed to a new climate or to new conditions.


Achene is a small, dry one-seeded fruit that does not open to release the seed.

Acid Soil

Acid soil has a pH less than 7.0. An acid soil is usually low in lime. Also caused by application of high amounts of acid-forming fertilizer. Most often found in rainy climates. Video


Aeration is the introduction of air into a material.


Aerobic describes organisms living or occurring only when oxygen is present.

Aggregate Fruit

An aggregate is a combination of two or more materials in order to form one.


Agronomy is the science of soil management and crop production.

Air Drainage

Air Drainage is a general term for gravity-induced, downslope flow of relatively cold air.

Air Layering

Air Layering allows for the growth of adventitious roots. Roots that form around the cut area are allowed to grow until they are well developed and the new plant is severed from the parent plant by cutting it off just below the roots and potting it up separately.

Alkaline Soil

Alkaline soil is referred to by some gardeners as “sweet soil.” The pH level of alkaline soil is above 7, and it usually contains a great deal of sodium, calcium and magnesium. Because alkaline soil is less soluble than acidic or neutral soil, availability of nutrients is often limited.


Allelopathy is the chemical inhibition of one plant (or other organism) by another, due to the release into the environment of substances acting as germination or growth inhibitors.


Anaerobic is relating to, involving, or requiring an absence of free oxygen.


Angiosperm is a plant that has flowers and produces seeds enclosed within a carpel. The angiosperms are a large group and include herbaceous plants, shrubs, grasses, and most trees.


Anuals are plants that complete their life cycles in one year or less.


The part of the flower,on the upper part of the stamen, in which pollen is produced.


A type of leaf or fruit spot disease caused by a fungus.


Anti-Transpirant is a substance, such as pine oil, that is usually sprayed on plant surfaces to reduce transpiration and inhibit water loss, which is called also antidesiccant.


Anthocyanins are a type of flavonoid, a class of compounds with antioxidant effects. Found naturally in a number of foods, anthocyanins are the pigments that give red, purple, and blue plants their rich coloring.


Apomixis is an asexual reproduction in plants, in particular agamospermy.

Approach Grafting

Approach Grafting is an easy graft to make in the right specialty situations. It happens naturally in the wild when two branches rub against each other and eventually seal together. In the garden or greenhouse, you use it to join one whole living plant to another.


Arms are all the main branches two years and older in a grape plant.


Duplicating a plant from any cell, tissue or organ of that plant.


Autotroph is an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.


Auxin is a plant hormone which causes the elongation of cells in shoots and is involved in regulating plant growth.


Ball & Burlap

Ball & Burlap is A ball and burlap tree is a tree that has been field grown from a seedling to a predetermined size, approximately 4 foot and up.


Banding refers to the practice of creating a band of fertilizer that runs alongside and a little below your rows of seeds. Banding your seeds with these “starter fertilizers” makes valuable nutrients available to early roots, helping seedlings to grow faster and bigger. ")

Bare Root

Bare Root

Bare root plants are dormant, meaning not actively growing, perennial plants that are dug up and stored without any soil around their roots. Usually these plants are dug when during dormancy and then refrigerated until it is time to use them.


Bark is the outer most part of the tree and other plants. The term bark is also employed more popularly to refer to all tissues outside the wood. The inner soft bark, or bast, is produced by the vascular cambium; it consists of secondary phloem tissue whose innermost layer conveys food from the leaves to the rest of the plant.

Bark Slipping

Bark Slipping si when the vascular cambium is actively growing and the bark can be easily removed in an even layer without harming the plant.

Bearing Age

Bearing Age is the length of time from planting to fruit bearing varies with the type of fruit.


A berry is a simple fruit with a fleshy pericarp.


A plant having a two year life cycle. The first year growth is typically vegetative. The secDond year the plant fruits and dies.

Biennal Bearing

Biennal Bearing is the tendency to only grow fruit every other year.


A Bine is a long, flexible climing stem.


Biochar is a type of charcoal that is used for agricultural purposes which contains high nutritional content.

Biochemical Pesticide

Biochemical Pesticide are natural pesticide that utilizes naturally occurring substances instead of chemicals to control pests. Biochemical pesticides are non-toxic and natural mechanisms that can be used to inactivate or kill the pests, often by interfering with mating.")


Biome is a large naturally occurring community of flora and fauna occupying a major habitat, e.g. forest or tundra.

Biotic Factor

Biotic factors are the living components of an ecosystem. They are sorted into three groups: producers or autotrophs, consumers or heterotrophs, and decomposers or detritivores.

Bitter Pit

Bitter Pit is the physiological disorder caused by calcium deficiency. Appears as small, dark, round depressions on skin of affected apples.


The Blade, or lamina, is attached to the plant stem by a stalklike petiole.


The process of Blanching is to keep plants from the light to prevent photosynthesis and to cause white tissue growth.


A Bloom is when a tree flowers or is in flowering.


A Bract is a modified leaf or scale, typically small, with a flower or flower cluster in its axil. Bracts are sometimes larger and more brightly colored than the true flower, as in poinsettia.


A tree Branch is a woody structural member connected to but not part of the central trunk of a tree.


Broadleaf plants and trees are those with leaves that have a flat, relatively broad surface.

Brown Waste

Brown Waste is most commonly are dried leaves, straw, and wood chips.


A Bud is small lateral or terminal protuberance on the stem of a vascular plant that may develop into a flower, leaf, or shoot.


Budding is becoming larger as part of the process of normal growth.


A bulb is any plant that stores its complete life cycle in an underground storage structure. Bulbs or bulb-like plants are usually perennials. They have a period of growth and flowering.


A Bulblet is an aerial deciduous bud produced in a leaf axil or replacing the flowers and capable when separated of producing a new plant.

Bulk Density

Bulk Density is the mass of a given volume of dry soil and pore spaces of a soil.


Basal is forming or belonging to a bottom layer or base.


C Soil Horizon

C Horizon Soil is the subsoil layer below the A and B horizon that contains much of the original parent material that has not been weathered.


Calcareous soil is a soil that has high levels of both magnesium carbonate and calcium that reduce acidity in the soil. Calcareous soil can have a coarse to fine texture as well as differing levels of sand, silt or clay.


Callus are a cluster of cells that are from the parenchyma and serve no known function.


Cambium is a cellular plant tissue from which phloem, xylem, or cork grows by division, resulting in secondary thickening.


Cankers on trees appear as isolated dead areas on the bark, stems, branches or twigs of a tree. Cankers may appear as discolored areas or depressed places on the bark.


A Capsule is a dry dehiscent fruit that splits open to release seeds and comes from flowers that had many pistils.


Caylx are the sepals of a flower, typically forming a whorl that encloses the petals and forms a protective layer around a flower in bud.

Carbon Dioxide

Carbon Dioxide is a colorless, odorless gas produced by burning carbon and organic compounds and by respiration. It is naturally present in air and is absorbed by plants in photosynthesis.

Carbon Fixation

Carbon Fixation is the starting phase of two steps in the Calvin–Benson cycle and it consists in the enzymatic addition of a carbon atom from a CO2 molecule to a five-carbon molecule named RuBP.


Carpel is the the female reproductive organ of a flower, consisting of an ovary, a stigma, and usually a style. It may occur singly or as one of a group.


Caryopsis is a dry one-seeded fruit in which the ovary wall is united with the seed coat, typical of grasses and cereals.

Casperian Strip

Casperian Strip is a conspicuously thickened wall area one cell layer deep surrounding primary roots; it prevents excess soil solution from being pulled directly into the central part of the root where the xylem is located.


A Cell is the basic unit of a plant that contains many different organlelles, or structures, that drive the plant processes.

Cell Expansion

Cell Expansion is the second stage of seed development in which seeds undergo a swift enlargement because of an accumulation of food reserves.

Central Leader System

Central Leader System is the of training, the trunk forms a central axis with branches distributed laterally up and down and around the stem.

Chilling Injury

Central Leader System is the of training, the trunk forms a central axis with branches distributed laterally up and down and around the stem.


Chlorophyll is a green photosynthetic pigment found in plants, algae, and cyanobacteria. Chlorophyll absorbs mostly in the blue and to a lesser extent red portions of the electromagnetic spectrum, hence its intense green color.


Chloroplast is a plastid that contains chlorophyll and in which photosynthesis takes place.

Chronic Toxicity

Chronic Toxicity is is the development of adverse effects as the result of long term exposure to a toxicant or other stressor. It can manifest as direct lethality but more commonly refers to sublethal endpoints such as decreased growth,


Citrus is a tree of a genus that includes citron, lemon, lime, orange, and grapefruit. Native to Asia, citrus trees are widely cultivated in warm countries for their fruit, which has juicy flesh and a pulpy rind.


Class is the taxonomic rank that separates or identifies plants in aphylum. Class is above order in this ranking.

Clayey Soil

Clayey Soil is Swhen most of its mineral particles are very fine clays. Ideal soil for gardening are sometimes known as loam, or loamy soil, and it has a broad mixture of sand, clay, intermediate mineral particles, and a heavy does of organic material.


A Clingstone is a type of fruit containing a pit, also referred to as a stone, that attaches itself or clings to the fleshy pulp of the fruit.

Coconut Core

Coconut Coir is a fibrous material found between the internal shell and outer coat of a coconut.


A Collar is is at the back side of leaf where the leaf blade and sheath meet.


Collenchyma is tissue strengthened by the thickening of cell walls such as in young shoots.

Community Agriculture

Community Supported Agriculture(CSA) is a system that connects the producer and consumers within the food system more closely by allowing the consumer to subscribe to the harvest of a certain farm or group of farms.

Complete Fertilizer

A Complete Fertilizer is a fertilizer blend or mix that contains the three main plant nutrients: nitrogen (N), phosphorus (P), and potassium (K), in the forms of potash, phosphoric acid, and nitrogen.


Compost is made up of microscopic bacteria and fungi, along with earthworms, crickets, and many other life forms. Many fungi form symbiotic, or mutually rewarding, partnerships with plant roots, making it possible for vegetables to feed themselves more efficiently.

Compound Fruit

A Compound Fruit is one that develops from several ovaries in either a single flower or multiple flowers.


The Cone is the frit of a hop plant.


A Conifer is a cone-bearing seed plant.


A Cordon is a major branch that comes from the trunk of a vine.


A Cotyledon is the first leaf to emerge from a seed.

Cross Pollination

Cross pollination is when one plant pollinates a plant of another variety. The two plants' genetic material combines and the resulting seeds from that pollination will have characteristics of both varieties and is a new variety.

Crotch Angle

A Crotch Angle is the angle between a branch and the trunk,also called a for, is normally greater than 45 degrees in most species.


A Crown is the area on a plant where a root meets stem tissue.


A Cull is a disposable fruit usually used for compost or just thrown away.



When something is Deciduous it will lose its leaves annually.


Denitrification is the loss or removal of nitrogen or nitrogen compounds specifically the reduction of nitrates or nitrites commonly by bacteria in soil that often results in the release of nitrogen into the air.")


Desorbed is to cause the release of an adsorbed substance from a surface.


Dessication is the removal of moisture.


Dehiscentis characterized by splitting or bursting open.


Dicotyledonmeae is one of the two classes of flowering plants, distinguished by having two seed leaves within the seed. The dicotyledons usually have leaf veins in the form of a net, a ring of vascular bundles in the stem, and flower parts in fours or fives or multiples of these.")


Distal means when something is situated away from the center of the body or from the point of attachment.


A Domain is the highest and most inclusive taxonomic ranking for all living things.


Dormancy is a condition in which buds and seeds are inhibited from until a certain environmental requirement is met.


A Drupe is a fruit with a fleshy, soft mesocarp and a seed enclosed by a hard, stony endocarp.


DIF is a term used to mean the day temperature mius the night temperature.



Endocarp is the innermost layer of the pericarp which surrounds a seed in a fruit. It may be membranous or woody.


An Enologist is someone who is responsible for everything having to do with the science (chemistry and biology) of the wine.


Environment is the natural world, as a whole or in a particular geographical area.


Epidermis is the outer layer of tissue in a plant, except where it is replaced by periderm.


Erosion is the process of eroding or being eroded by wind, water, or other natural agents.


Ethylene is a natural chemical produced and emitted by fruits and vegetables and decaying plant materials.


Evergreen is a plant that has leaves throughout the year that are always green.


Evapotranspiration is the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants.


The Exocarp is the outer layer of the pericarp of a fruit.


Exfoliate means to come apart or be shed from a surface in layers.



Family is the taxonomic ran that separates or identifies plants in an order above the genus ranking.


Fertigation is a process in which fertilizier is added to irrigation water.


Fertilization is the processin which the male gamete combines with the female gamete to create a genetically unique organism.

Fertilizer Grade

Fertilizer Grade is a listing of fertilizer ingredients contained by weight.

Field Capacity

Field Capacity is the maximum amount of water a soil can handle against the pull of gravity.


A Filament is a thin stalk in the stamen that is supportive of the another.


A Flower is a shoot of determinate growth with modified leaves supported by a short stem. The flower is the structure responsible for reproductive processes of plants that bear enclosed seeds in their fruits.


A Follicle is a dry dehiscent fruit that splits along the length of the fruit releasing seeds for dispersal.


Freestone is a fruit where the pit falls right off the pit, while a clingstone would be the opposite.

Freezing Injury

A Freezing Injury is a condition in which the plants are dmaamged when low temperatures freeze the water in plant tissue.


A Fruit is an expanded and ripened ovary with attached and subtending reproductive structures. In most cases fruits are edible.


Fungicide is a chemical used to fight and prevent fungal growth.


Fungus is a eukaryotic organism which attaches itself to a host and ecomposes the organism while absorbing the nutrients from it.A Genome is the entire set of chromosomes of a plant. 1



A Genome is the entire set of chromosomes of a plant.


Genus is a subset of organisms within a family that share similar characteristics. Genus is above the species in taxonomic ranking.


Geotextile is permeable, inorganic mulch material made from plastic.


Germination is the trigger of active growth by the embryo, resulting in the rupture of seed coverings and the emergence of a new seedling plant capable of self sustaining.


Grafting is when you join together two different plants/trees or parts of plants/trees with the desire for them to grow into one plant ro tree.

Gravitational Water

Gravitational Water is free water that moves through the soil by the forces of gravity.

Green Industry

Green Industry is a section of horticulutre that cultivates and arranges outdoor plant materials to create spaces that are useful to people and the ecosystem.

Green Waste

Green Waste are organic materials that are often rich in nitrogen used to create compost. Materials such as leaves, fresh manure, grass clippings and coffee grounds are some examples of what is used for green waste.

Growth Medium

Growth Medium is any substance that contains nutrients and hormones that is used for plant growth.


Guys are ropes or cables that are attahced to trees to anchor them to the ground.


Gymnosperm is a non flwoering plant that develops with no ovary.


Hand Thinning

Hand thinning is the trim out a tree to provide more control of the thinning process.


Hardiness is the ability to endure difficult conditions.

Hardiness Zone

Hardiness Zones is the standard by which gardeners and growers can determine which plants are most likely to thrive at a location. The map is based on the average annual minimum winter temperature, divided into 10-degree F zones. See the Hardiness Zone link for all the zones.


A Hardpan is a impervious layer of soil.

Hardwood Cutting

Hardwood Cutting is a method of vegetative propagation in which mature, often dormant wood is rooted.

Heat Stress

Heat Stress is when a plant ro tree is suffering from high temperatures.


A Herbaceous is a plant that is non-woody and has soft stems.


A Herbarium is a repository of collected plant specimens.


Herbicid is a chemical which main purpose is to kill plants.

High-density Orchard

A High-density Orchard is on in which 150 to 180 trees are grown per acre of land that bears fruit within 2 to 3 years of planting.


Histodifferentiation is a stage in seed development when the embryo and endosperm develop distinct characteristics.


The Horizon is a layer of soil distinguished by properties and characteristics developed through the five factors of soil formation.

Horticultural Oil

Horticultural Oil is a pesticide treatment which in volves different types of oils that can be used to kill pests.


Horticulture is the science and business of cultivating plants.


A Horticulturist person who specializes in the art, science, technology and business of plant cultivation.


A Hydrometer is an insturment used to measure the percentage of slat, sand, silt and clay in a sample to determine the soil textural class.



ICBN stands for the International Code of Botanical Nomenclature which sets the rules for the naming and renaming of plant species.


Immbibition is the absorption of one substance by another, in particular the uptake of water by a plant or seed.

Inarch Grafting

Inarch Grafting is a joining method used to support a damaged plant stem in which existing shoots or suckers growing from the rootstock or compatible rooted plant material planted around the tree is used as scions.

Incomplete Dominance

Incomplete Dominance is a phenomenon where a plant displays characteristics of both parents.


Indehiscent is a type of dry fruit in which the fruit wall does not split at any certain point or seam at maturity. Indeterminate growth. Growth that is potentially limitless.


Inoculum is a pathogen that is capable of causing infection and disease when transferred to the appropriate host and environment.


Insecticide is a chemical used to prevent, control, or decimate insect populations.

Insoluble Fertilizer

Insoluble Fertilizer is a fertilizer that does not readily integrate with water.


Internodes are these spaces betwween nodes.


Interplanting is a method on planting early


Interstock is the intermediate stem piece grafted between the upper and lower pars of the graft.


Irrigation is the practice of dispersing water to land or soil to assist in growing plants.


June Drop

June Drop is the natural process of apples naturally shedding fruitlets in early summer.

Juvenile Stage

Juvenile Stage is a period of growth that occurs before plants reach adult form.



A Kernel is a softer, usually edible part of a nut, seed, or fruit stone contained within its hard shell.


A Knee is a distinctive structure forming above the roots of a tree. Think swamp trees.


Kingdom is a taxonomic rank, which is either the highest rank or in the more recent three-domain system, the rank below domain.


Lag Phase

A Lag Phase is a period during the germination of a seed where there is little or no water introdcued, yet with high cellular activity to prepare the seed to grow.


Lechate is water that is collected after it has percolated through the soil.


Leaching is when nutrients move out of the soil and into groundwater.

Leaf Bud Cutting

Leaf Bud Cutting is the cutting of a single node and adjacent internode tissue with the leaf attached used to propogate a new plant.

Leaf Cutting

Leaf Cutting is a way of cutting a leaf or portion of a leaf to be used to propagate a new plant.

Leaf Mesophyll

Leaf Mesophyll is the tissue that builds the internal layers of leaves.


A Legume is a dry dehiscent that opens along two seams at maturity.

Light Quality

Light Quality is the analyzed wavelengths of light that reach a plant.


A Ligule is a thin strucutre that clasps the top of the leaf sheath.

Loamy Soil

Loam soil is a mixture of soil that is the ideal plant-growing medium. It is actually a combination soil, normally equal parts of clay, silt, and sand, which gives the benefits of each with few of the disadvantages.


Locavore is a person who delights on a diet of only principally locally grown or produced food.



Macronutrient is a nutrient high in quantities for good plant growth and development.


Macropore is a large pore space in soil. Manometeris used to measure static air pressure.


Manometer is used to measure static air pressure.

Maturation Drying

Maturation Drying is the stage for a seed when development has reached physiological maturity.


Mesocarp is the the middle layer of the pericarp of a fruit, between the endocarp and the exocarp.


Microclimate is a small area with the different environmental conditions than the surrounding area.


A Microgreen, typically a sprout, is a recently germinated plant that is edible.


Micronutrient is a nutrient essential for plant growth but needed in small amounts.


A Micropore is a small pore in the soil through which capilary water moves.


Molluscicide is a chemical product used to control snails and slugs and any other type of mollusk.


A Monocotyledoneae(monocot) is a seed with only one cotyledon(first leaf) in the seed, parallel-veined leaves and floral structures in multiple of three.


A Monophagus is an insect that likes only one type of plany for its consumption.

Mound Layering

Mound Layering is a propogation method in which soil is piled on the crown of the plant and the new shoots for adventition roots that can be severed and transplanted.


Morphologyis the the branch of biology that deals with the form of living organisms, and with relationships between their structures.


MSDS is the material safety data sheet which contains information on the potential health impacts of chemicals and other dangerous substances.


Muck is soil composd of mostly decomposed organic matter.


Mulch is a covering, as of straw, compost, or plastic sheeting, spread on the ground around plants to prevent excessive evaporation or erosion, enrich the soil, inhibit weed growth.


Mulchmat is a nonwoven wool or cotton matting that is used to hold topsoil, control temperature, stunt weed growth, prevent erosion and retain moisture for soil.


Mycorrhiza is a fungus that grows in association with the roots of a plant ina symbiotic or mildly pathogenic relationship.



NADPH stands for Nicotinamide adenine dinucleotide phosphate and it is a molecule that acts as a carrier for electrons in photosynthesis.


Nanometer a nanometer is the unit of measurement used to quantify light wavelengths.


Necrotic Lesion

Necrotic Lesion is the tissue death that often occurs in plant leaves as spots along the margins or on the leaf entirely. This is main the result of lacking nutrients or could also indicate a pathogen.


Nematicide is a chemical product used to control nematodes.


Nematodes are a roundworm that lives in the soil and has the potential to be a parasite to some plants.

Night Interuption

Night Interuption is a methog of disrupting the dark period with light by creating a long day simulated effect.


NIOSH stands for the National Insitute of Occupational Saftety and Health. This organization conducts research and makes recommendations dealing with workplace safety, injury and illness.


Nitrification is when several species of soil-dwelling bacteria oxidize ammonium ions into nitrite ions.


No-till is the practice of planting new plants in the crop residue from the season before it.


Nodes is a location on the stem where a leaf develops.

Non-selective Herbicide

Non-Selective Herbicide that will kill any plant, not just a specific type.


Nontunicate is a type of bulb that has fleshy scales with no dry covering.


A Nut is a dry, indehiscent fruit that has a harded pericarp with a loose seed contained within it.

Nutrient Film Technique

Nutrient Film Technique(NFT) is a hydroponic method that circulates a targeted stream of water containging nutrients over the roots in a hydroponic system.


O Soil Horizon

The O Soil Horizon is mostly organic matter such as decomposing leaves or grass. The O horizon can be thin in some soils, thick in others, or not present at all.")


Offshoots are short, horizontal stems that occur in whorls or near whorls at the crown of stems.

Oil Bodies

Oil Bodies are lipid droplets that are found in cells in a plant and are mostly concentrated in fruit and seeds.


Oligophagus is a type of insect that feeds on multiple plant species that are soemwhat cloesly related.


Oomycete is a filamentous protist, which include watermolds and mildews that can cause disease, in the form of blights and rots.


Order is the taxonomic ranking that separates or identifies plants ina class and is ranked above family in taxonomic rankings.

Organic Food

Organic Food is a way of producing food without using chemicals or haveing the plants genetically modified in any way.

Organic Matter

Organic Matter is any matter collection of organisms that is alive or dead.


Oxygen is a colourless, odourless, tasteless gas essential to living organisms, being taken up by animals, which convert it to carbon dioxide; plants, in turn, utilize carbon dioxide as a source of carbon and return the oxygen to the atmosphere.

Open Center System

The Open Center System is a fruit tree training method that keeps the center of the tree clear of large branches to allow for the pentration of sunlight to the fruit producing wood.


Palmate Leaf

A Palmate leaf is a compound leaf with all the leaflets arising from one point at the end of the leaf stalk.

Parasitic Plant

A Parasitic Plant is a plant that anchors into another plant and gets it resources from the hosts vascular system.


Paranchyma is plant tissue that is made up of the vascular tissue of the outelayers(cortex), inner layers(pith) of the stems and roots as well as the itnernal layers of leaves(mesophyll)

Parent Material

Parent Material is material that is the source of the soil having been broken down. Examples of this would be bedrock, sediment or organic material.


A Pathogen is a organism that causes disease.


A Pathologist is someone who studies disease.


A Pedologist is someone who studies soil.


Pedology is the study of soil in it's natural environment.


Peds are aggregates produced through the binding of sand, silt, and clay particles.

Perched Water Table

A Perched Water Table is located about unsaturated soil due to compaction or some sol formation condition.


Perennialis a plant that just keeps coming back year after year.


The Pericarp is the fruit wall, consisting of three distinct layers; the exocarp, the mesocarp, and the endocarp.


The Periderm is the outside layer in a woody plant that provides protection and prevents water loss.


A Pest is a critter(organism) that loves to damage or disrupt growth of plants. Pests commonly take on the form of weeds, birds, rodetns, insects, mammals, snails and nemotodes. Pests can additionally take on the form as pathogens such as bacteria, virus, fungi and oomycetes.


Pesticide is a chemical used to combat and control pests like insects, weeds, fungi rodents and other entities that like to cause damamge to a plant.


A Petal is a modified leaf that surrounds the male and female reproductive parts of a plant.


The Petiole is essentially the leave stalk.


PGR is known as Plant Growth Regulator which is a synthetic or natural hormone that changes plant growth rates in either a innhibitor mode or as an accelerant.


pH is a measure of acidity or alkalinity, expressed as the negative log of the hydrogen ion concentration. A pH of 7 is neutral; less than 7 is acidic more than 7 is basic.

pH Paper

pH Paper is a test strip that changes color to indicate a pH level of soil to determine acidity or alkalinity.


Phenol is a natural occuring chemical compound in seeds that may prevent germination.


Phloem is plant tissue that carries photosynthetic materials synthesized in the leaves down to the plant and provides structural supportas wel. It is also commonly known as vascular tissue.


Photoblastic is a characteristic of seeds that have a germination response to the presence or absence of light.


Photocell is a device that reads the amount of light. The main measurement that is reads is in foot-candles.


Photodormancy is when seeds require a period of either light or dark conditions for germination.


Photoperiod is a block of time of day length when light is present and the relationship between the dark and light periods.


Photosynthesisthe process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.


Phylum is a principal taxonomic category that ranks above class and below kingdom.


Phytohormone is a naturally occuring chemical in a plant that regulates growth and other functions.


Phytophagus is an insect that gets the munchies for plants.


Phytoremediation is a manner of using living plants to remove contaminants from the soil.

Phytosanitary Certification

A Phytosanitary Certification is a document that shows a plant has been inspected and is free of pathogens, insects and weeds. It accompanies a consignment and is presented to the relevant officials upon arrival in the importing country.


Phytotoxicity is a poisonou effect by a sunstance on plant growth.


A Pinnate is a compound leaf with the leaflets arranged along both sides of the midrib.


A Pistil is the female reproductive organ, consisting of the stigma, style, and ovary.


The Pith is the inner layer of plant tissue of stems and roots.

Placement SAE

Placement SAE is a learning project in which students intern with the agriculture or similar industry.


A Plantlet is a plant that is in its infancy.


A Plug is generally a seed that is grown in a container for transport eventually.


A Plumule relates to a shoot that is developing on a seedling.


Polarity references the spatial orientation within plants.


Pollination is when pollen grains from the male anther of a flower transfer to the female stigma.


Polyphagus is a type of insect that likes to munch on a wide variety of plants, not just one type.


Polyphenols are are beneficial compounds in many plant foods that can be grouped into flavonoids, phenolic acid, polyphenolic amides.


A Pome is a fruit with a tough endocarp that encloses the seeds. Apples, pears, quince are all pomes.


A Pomologist is a scientist who is responsible for ensuring the healthy growth and breeding of fruits and nuts, as well as the trees and bushes on which they grow.


Pomology is the art of cultivating, processing, storing and processing fruits and nuts.


Porosity is when you have space or gaps between objects.


The Postharvest is the stage of crop production immediately following harvest, including cooling, cleaning, sorting and packing.

Preformed Root

Preformed Root are roots with existing root initials.


Priming is a way to greatly impact germination rate and uniformity in seeds through a process of hydrating and then drying.


Primocane-fruiting is a first year bramble that produce fruit at the top of the cane.


Propogate is a way of growing plants using methods like rooting or cutting.


Pruning is the removal of plant parts to maintain a desirable form by controlling the direction and growth.


Pyrolysis uses heat, with the absence of oxygen, material for decomposition.


Pyruvate is a compound that gives energy to plant cells. This is part of the Kreb cycle in respiration.



Q10 is a term used to describe the doubling of reactions as a biological response to increass in temperature in 18 degree(f) increments.


Quiescent is a state of inactivity.



A Radicale is the seed root of a seed, or more commonly called the embryonic root.

Radicle Protrusion

Radicle Protrusion is the last period of germination of a seed which entails the emergence of the seed root.

Relative Humidity

Relative Humidity is a measurement in the amount of water vapor in the air as compared to the amount of vapor the air can hold at a given temperature.

Renewal Pruning

Renewal Pruning is the process of removing a portion of a plants old mture stems each season from the ground up to stimulate new growth.


Rhizobia is a bacteria that converts elements such as nitrogen into a usable form that can be taken up by a plant.


Rhizomatous is a plant that produces underground lateral stems know as rhizomes.


Rhizome is a stem structure tha is modified and grows horizontally below or near the soil surface. This produes roots that grow on the bottom and shoots on the top.


Rodenticides are chemicals that are used to eradicate rodents.


A Root is the vegetative anchor of a plant that absorbs water and minerals and often stores food.

Root Pruining

Root Pruining is the act of cutting the roots of a plant to promote growth in flowering or frutiing.

Root Zone

A Root Zone is the soil surrounding the root that serves as a reservoir which the plant can draw moisture and nutrients.


Rootstock is root material onto which a productive and useful fruit variety is grafted.


Rosette is a tight cluster of leaves growing in a bunch due to poor shoot growth, typically a system of boron or zinc deficiency.


A Runner is a specialized stem that grows horizontally above the ground to form a new plant.


Saddle Grafting

Saddle Grafting is a graft where the scion is cut in the shape of a saddle and is seated on the top of the rootstock.


A Samara is a dry indehiscent fruit in which part of the fruit wall is extended as a wind.

Sandy Soil

Sandy Soil is soil that is primarily sand and has large particles and pore spaces.


Saturation is the point at which soil or soiless media are filled with water to the point that there is no more room in the pores.

Scaffold Branches

Scaffold Branches are primmary branches that arise from the tree trunk and form the main structure of the canopy.


Scarification is achemical or physical treatment given to seeds to break or weaken the seed coat to allow for germination to occur.


Schizocarp is the dry indehiscent fruit that splits at maturity into two or more seeded parts.

Scientific Name

Scientific Name is a name that must contain both the genus and the specific epithet for a plant species.


A Scion is the upper part of the union of a graft.


Sclerenchyma is the strengthening tissue in a plant, formed from cells with thickened, typically lignified, walls.


Scouting is essentially a systematic checking of fields, orchards or other grow areas to monitor and identify pest problems early and manage anything that can hinder crops and effect cost.


A Seed is a plant embryo with associated stored food encased in a protective seed coat.


Sedge is a type of weed that is characterized by parallel venation and a triangular, solid stem.

Selective Herbicide

Selective Herbicide is as it is names, very selective about plants it will kill and the ones it won't.


Senescence is the aging or ripening of harvested crops.


Sepal is a leaf that encases and protects a flower bud.

Serpentine Layering

Serpentine Layering is a process of layering shoots horizontally to the ground and exposing some buds while others are coveredin soil in an alternating pattern.

Side-veneer Grafting

Side-veneer Grafting is a method of joining plants by taking a piece of bark from the side of a plant stem and a scion is then attached to the cut area. Once the graft has healed, the top part of the rootstock is cut off.


Silique is a dry dehiscent fruit with a seedpod which splits along two sides as the seed inside remains attached to the fruit strucutre.


Silviculture is the science of planting, managing, caring and repairing forests. Think forestry.

Slope Orientation

A Slope Orientation is the direction in which a slope of land is facing from a persons perspective.

Slow-release Fertilizer

Slow-release Fertilizer is a fertilizer produced with a coating of particles with a wax or other insoluble or very slowly soluble material to provide slow release of the encapsulated materials.


Softwood is the soft new growth on a woody plant.


Soil is the outer, weathered layer of earth crust made up of inorganic particles, organic matter, microorganisms, water, and air.

Soil Auger

Soil Auger is a tool that pulls deep soil sample extractions to varying depths.

Soil Probe

Soil Probe a tool, like a soil auger, used to pull soil core samples.

Soil Structure

Soil Structure is aggregated into peds by the binding together of clay, sand, silt and other materials.

Soil Survey

Soil Survey is essentially a study of the soil in a determined area.

Soil Texture

Soil Texture reflects the proporation of different minieral particles present in the soil.

Soilless Media

Soilless Media is a sterile mix of natural ingredients used to raise plants in various environments and containrs. More often refered to as potting soil.


Soluble is a ability to dissolve things into water easily.

Somaclonal Variation

Somaclonal Variation are configurations seen in plants that are produced by tissue culture or ones that have been subsultured.


Sorption is absorption and adsorption considered as a single process.


Species is the lowest and least inclusive ranking in plant classification.

Specific Epithet

Specific Epithet is what comprises the second half of a scientific name for a plant. It is usually description of a plant feature or refers to a name or a place.

Splice Grafting

Splice Grafting is a form of grafting in which a simple diagnoal cut of the same length and angle is made on the rootstock and scion and placed with cambial layers aligned.


A Spur is a cane that has been pruned to have a small amount of nodes.


Stamen is a part of the flower consisting of the anther and a slender filament that holds the anther in a position favorable for pollen dispersal. It is the male reproductive organ of a flower.

Static Pressure

Static Pressure is the force exerted on somethign by liquid or gas that is still.

Stem Cutting

Stem Cutting is just a portion of the stem being cut.

Stock Plant

Stock Plant is material kept for the purpose of porpagation.


Stolon are horizontal stems that grow above ground and produce plants or tubers.


Stoloniferous is a plant that generates stolons.


Stomata are pores in epidermal plant cells that function to allow for gas to exchange and control water loss.

Stone Fruit

Stone Fruit is a fruit that has one main pit.


Strain is long term pressure, tension on a plant.


Stratification is the storing of seeds at low temperatures under moist conditions to break physiological dormancy or rest.


Stress is short term pressure or tension on a plant. Suberin is a waxy substance that helps sel the wounds of plants.


Suberin is a waxy substance that helps sel the wounds of plants.



Substrate is soil or medium where the plants roots grow.

Sump Pump

A Sump Pump is a motor that pulls water from one location to another for the sake of irrigation.

Sump Tank

Sump Tank is a holding container for the water moved by sump pumps.


Sunscald is a condition that arises from damage from heat, humidity or intense sunlight.


Superphosphate decribes using a high level of phosphate in material.

Surface Horizon

Surface Horizon is the visible outer most layer of oil. This is also referred to as Tpsoil or the A horizon.


A Symptom is the plants reaction to a disease in the form of wilting or blight.

Systemic Herbicide

Systemic Herbicide is a chemical can move within the plant from its point fo entry as a method to kill the plant.

Systemic Insecticide

Systemic Insecticide is a chemical can move within the insect from its point fo entry as a method to kill the insect that attacks your plants.

Systemic Pesticide

Systemic Pesticide is a chemical that moves through a plants vascular ssystem and focuses on insects with sucking or piercing mouthparts.



Tannins are natural occuring chemical compounds found in wine grapes that impact the bitterness, astringency and complexity of wine.


Taxonomy is the branch of science concerned with classification, especially of organisms


Thatch is a layer of dead grass or organic matter that can form a mat beneath leaf bblades and above the root zone.


Thermodormancy is a secondary form of dormancy that can inhibit the germination process.

Thermo Period

Thermo Period is a relationshiop between day and night temperatures and the affect on the plant growth.


Thermostat is an instrument that measures the temperature.

Thinning Cut

A Thinning Cut is used to prevent crowding in a fruit tree by removing an entire branch back to its base.


A Thylakoid relates to a sac surrounded by membranes on which light reactions of photosynthewsis take place.


A Tiller is a stem that develops from the crown of the parent plant and grows upward within the enclosing leaf sheath.


Tillering is the process of new stems(tillers) being created by a main plant.


Tilth is a term used to describe quality soil for growth, with regards to texture, structure and pore space.

Tissue Culture

Tissue Culture is a collection of techiniques used to mantain plants in a nurtient medium under sterile conditions.


A Topography is the general overlay of the slope and elevations of a specified land area.


Topsoil is the outermost layer of soil which is also refered to as the surface horizon or the A horizon.


Topworking is grafting new scion material onto a mature tree.


Toxicity is the level of which something is poisinous.


Transpiration process in which water pulled upward from the roots through xylem cells and released into the air in a gas state.

Tree Plot

Tree Plot is a very specific, measured area of trees.


Tuber is a swollen, underground stem that is a storage organ the plant.


A Tubercle is a small aerial tuber which is created in the axil of a leaf.


Turgor is the pressure with a plant cell that gives the plant structure rigidity and support.



If you have a Pomology wor dthat starts with U email it to us at info@joticle.com.



Variegated a leaves with with green and white striped pattern instead of the typical all-green look.


Variety is a form of sub classification of a species that is marginally different, yet not varied enough to sanction a new species.


Vascular is a plant that is characterized by the presence of conducting tissue. The two types of vascular tissue, xylem and phloem, are responsible for moving water, minerals, and the products of photosynthesis throughout the plant.


Vegetative parts are the stems, leaves and roots of a plant harvested for different purposes such as foods, flavorings, perfumes or medicine.

Vegetative Propagation

Vegetative Propagation is the process of starting a new plant fromt the existing material of a plant.


Vermicompost is a type of compost in which worms, bacteria and microbes are used to convert the organic matter into fertilizer.


Vermiculite is a material that is comprised of small pieces of mica that can readily absorb water.


Vernalization is the process of exposing plants to low tempertatures as a means of stimulating flowering.


Verticutting is a process of thatch control which is done by a machine which slices thatch layers to create an opening for water penetration and air exchange.


Viable is being able to germinate.


Viniculture is the cultivation and harvesting of grapes. It is a branch of the science of horticulture.


Virus is a microscopic organism that infects and lives off other organisms.


Vivipary is the phenomenon that involves seeds germinating prematurely while they are still inside or attached to the parent plant or fruit.


Volatilization is a process in which fertilizer components change from a solid to a vapor and are released intot he atmosphere.


A Vacuole is a large cavity in a plant cell that stores waste products, pigments, cell sap and other liquids.


Water Culture System

Standard water culture systems and deep water culture systems (DWC) are about the simplest types of hydroponic systems available.

Water Sprout

Watersprout wood is juvenile and fast-growing, fed on the water and nutrients provided by the established parent wood.


Weathering is the process of disintegration of rock from physical, chemical, and biological stresses.

Wedge Grafting

Wedge grafting, also known as cleft grafting, is a method of propagating new limbs on plants such as fruit trees or bushes by removing a healthy branch, known as a scion, and physically connecting it to the stock of another tree at the desired location.

Whip-and-Tongue Grafting

The whip-and-tongue graft is a form of detached scion grafting where a scion is cut with a grafting knife using a single motion. After the first cut, a second reverse cut is made three-quarters of the way into the first cut to form the tongue.


A whorl or verticil is an arrangement of sepals, petals, leaves, stipules or branches that radiate from a single point and surround or wrap around the stem.


Preparing everything for the winter.

Wound-induced Root

Wound-induced roots develop only after the cutting is made, in response to wounding in preparing the cuttings.



Xeriscape is landscape in a style which requires little or no irrigation.


Xerophyte is a plant adapted to grow in very dry environments. Lithops are a good example


Xylem is the vascular tissue in plants that conducts water and dissolved nutrients upward from the root and also helps to form the woody element in the stem.



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A Zygote is a diploid cell resulting from the fusion of two haploid gametes, a fertilized ovum.