A
Acidity (acid soil): a soil condition which has a pH below 7.0.
Active ingredient: the portion of a product responsible for its activity.
Aerification: the process of improving the movement of air, water and nutrients into the soil by removing thatch, slicing the soil or removing plugs of soil.
Agronomy: the theory, study and practice of field-crop production and soil management.
Algae: microscopic plants generally found growing on the soil surface in areas of poor sunlight, poor drainage, or low fertility.
Alkalinity (alkaline soil): a soil condition which has a pH above 7.0.
Alternate: an orderly growth with a leaf or seed arranged on one side and then the other, along a stem or spike.
Ammoniacal: an immediate release source of nitrogen used in some fertilizers
Analysis (product): the statement on a package listing the ingredients and their percentages by weight.
Annual: any plant which germinates, matures, produces seed and dies within one growing season.
Asexual: without sex. Propagation by sod, stolons or offshoots.
Auricles: projecting arms of a grass leaf, located at the collar, which may or may not clasp the stem.
Axil: the point where the leaf grows from the stem.
B
Bahiagrass: a coarse-textured, warm season grass which spreads by tillers and some rhizomes.
Barrier: a chemical boundary located below the soil surface to prevent the germination or growth of undesirable plants.
Bentgrass: a cool season grass of fine to medium texture with stoloniferous growth.
Bermudagrass: a fine to medium-textured grass which forms a turf due to vigorous rhizomes and stolons.
Biennial: a plant which completes its life cycle in two years. Forms as rosettes the first season, and produces flowers and seeds the second.
Blade: the wide or expanded part of a grass leaf extending from the sheath.
Blight: rapid discoloration and death of tissues, especially leaves, leaf sheaths and stems—with no definite pattern.
Blind seed disease: a disease affecting turfgrasses grown for seed that causes a reduction in germination percentages.
Bluegrass: a cool season grass of medium-fine texture, reproducing vegetatively by rhizomes and tillers.
Broad leaved: referring to dicot plants.
Bud: the undeveloped state of a stem or flower generally covered with overlapping leaves.
Bulb: a thickened or fleshy underground stem usually made up of overlapping, foodstoring scales.
C
Calcium carbonate equivalent: refers to the number of pounds of calcium carbonate (CaCO3) required to neutralize a ton of fertilizer.
Calibrate: measure rate of application of a spreader under defined conditions.
Capillary Action: movement of water and nutrients between soil particles and between the cells of any organism.
Capsule: a closed receptacle, containing seeds, composed of two or more parts.
Carrier: the material added to a product to facilitate its distribution.
Centipedegrass: a coarse-textured, stoloniferous grass which grows best on acid soil.
Certified seed: seed grown under inspection by a certifying agency and when mature, approved as to its genetic identity, purity and high quality standards.
Chaff: the husks of grain or other waste material separated from pure seed during cleaning.
Chlorophyll: the green pigment in plants which is vital for photosynthesis.
Chlorosis: the result of poor chlorophyll production in green plants which causes a yellowish color.
Clay soil: indicates a soil type consisting primarily of clay —% to 3A of the content.
Clone: hopeful new grass varieties being grown in the field for the purpose of producing enough seed to last the duration of the testing program.
Clusters: the grouping of flowers or leaves on a plant.
Collar: a narrow band marking the place where the blade and the sheath join.
Compacted soil: a condition where the soil particles are packed tightly together forcing out all air and moisture.
Compost: a decomposed mixture of plant and animal waste to which lime, fertilizer or soil may have been added.
Contact herbicide: a herbicide that kills weeds by direct contact rather than by translocation.
Contaminant: any undesirable plant in turf or undesirable seeds in a blend.
Contour: the grade or slope of a turf area or land surface.
Control: to limit population and spread of a pest to tolerable levels.
Conversion: gradually changing an old turf into turf of a more desirable grass without total renovation.
Cotyledon: the first leaf, or leaves, that emerge from the seed plant.
Crop: a term used on a seed label —meaning any plant grown for profit.
Crown: the above ground base of a grass plant from which all growth begins.
Culm: the stem of grasses and sedges.
Cultivar: a variety of plants, which retain their distinguishing features when reproduced.
Cultivate: preparing the soil for seeding.
D
Debris: the accumulation of unwanted material in turf or seed bed.
Decay (decompose): the breakdown of living matter into chemical forms.
Denitrification: the biochemical reduction of nitrogen in the nitrate or nitrite forms to elemental nitrogen.
Density: the thickness of turf measured by the number of plants in a given area.
Desiccation: the drying out of turf—usually used in reference to "winter desiccation" when there is lack of snow cover to protect the turf from drying winds.
Dichondra: a vining, broadleaf plant which is used successfully as a ground cover in California.
Dicot (dicotyledon): a plant emerging from the seed with two leaves.
Disease: a condition caused by parasitic organisms, resulting in damage to the grass plant.
Disease organism: the parasite (usually a fungus) which causes injurious effects to the grass plant.
Disease tolerance: the ability of a plant to resist a disease.
Dormant: a reduction of growth and other normal life functions of perennial plants caused by stress or seasonal changes.
Dry wilt: a condition caused by lack of moisture in the soil.
Duff: an organic layer consisting of partially decomposed vegetative matter such as leaves, roots, stems and stolons.
E
Ecology: the study of the inter-relationships of organisms to one another and to the environment.
Environment: all the external conditions which affect the growth of an organism.
Epidemic: a disease outbreak among a population at one time.
Epidermis: the outermost layer of cells or tissue of a plant.
Ergot: a disease affecting the flowering parts of seed production turfgrasses, causing large reductions in seed yield.
Erosion: the wearing away of the soil by wind, water or ice.
Eutrophication: a condition occurring in bodies of water where the plant is deficient in oxygen and aquatic plants-are abundant. This process is accelerated by the surface runoff of nutrients such as nitrogen and phosphorus.
Evaporation: the process by which a liquid is changed to a vapor or gaseous form.
Evapotranspiration: water transpired by plants plus that which has evaporated from the soil.
F
Field capacity: the remaining water content of a soil after it has saturated and drained for a specific length of time.
Fertilizer: any material or mixture which supplies the necessary plant nutrients, usually nitrogen, phosphorus and potash.
Fertilizer analysis: the percentage by weight of the components found in a fertilizer. For example, a fertilizer with a 10-6-4 analysis contains 10 percent nitrogen (N), 6 percent phosphoric acid (P2O5) and 4 percent potash (K2O).
Fertilizer grade: the guaranteed minimum analysis of the major nutrients found in fertilizer
Fertilizer ratio: a ratio of the basic weights of the major nutrients found in a fertilizer. For example, a fertilizer having an analysis of 18-6-6 would have a 3:1:1 ratio or 3 parts of N to 1 part of P and 1 part of K.
Fescue: cool season grasses of fine and coarse textures reproducing vegetatively by tillers or rhizomes.
Foliage: the leaf covering of a plant.
Fructification: production of spores by fungi.
Fungi: plants lacking chlorophyll that cannot produce their own food; parasitic forms cause turf diseases.
Fungicide: any chemical which controls or destroys the growth of a fungus.
G
Germination: the beginning of visible growth of a plant as it emerges from the seed.
Ground cover: a low-growing plant used in place of turf—example: dichondra, ice plant, ivy.
Grub: the larva stage of various beetles; one of the insect invaders of turf
Guard cells: a pair of cells which regulate the opening and closing of the stoma.
H
Habit (growth): the general pattern of style of plant growth.
Habitat: the environment which supplies the needs for plant or animal life.
Herbicide: a chemical used to destroy or inhibit plant growth.
Hermaphrodic: reproduction by one individual containing both functional male and female reproductive organs.
Heterogeneous: refers to having unlike qualities or differing in kind.
Homogeneous: consisting of similar parts orelements.
Humus: decomposed organic matter.
Hybrid: a plant produced by the crossing of two species with different characteristics.
Hygroscopic (water): water held so tightly by soil particles that it is unavailable to plants
Hyperplasia: overgrowth due to increased cell division.
Hypertrophy: overgrowth due to abnormal cell enlargement.
Hyphae: threads of fungal growth.
I
Impregnate: to force particles of one substance between the particles of another.
Inert: any substance which does not take an active part in a chemical reaction or anything in a seed blend that will not grow.
Infection: the process of gaining entrance and becoming a parasite within a host plant.
Infestation: the spread of harmful weeds, diseases or insects in a lawn,
Inflorescence: the flower cluster of a plant and its mode of arrangement.
Inorganic: natural or synthetic elements or chemicals of non-living material.
Insecticide: any chemical which destroys insects.
Insoluble: any substance which cannot be dissolved by a given liquid.
Internode: the portion of a stem or other plant parts between two nodes.
Irregular: an arrangement of leaves, stems or seeds which have no pattern or uniform order.
L
Larva: the immature, wormlike stage of insect development.
Lateral growth: the sideward rather than upward growth of a plant or leaves.
L.D.: means the lethal dose of a pesticide. An LD50 indicates a lethal dose that will kill 50 percent of a given population of test animals under stated conditions.
Leaching: the removal of materials in solution by the passage of water through soil.
Leaf: the lateral outgrowth of a stem.
Lesion: a scar or mark on a plant caused by a disease or injury.
Ligule: an upright projection of tissue at the junction of the blade and sheath of a grass leaf
Lime: Lime generally refers to calcium oxide (CaO). There is a variety of materials which composes the various types of limes. The most commonly used forms of lime are ground limestone (carbonates), hydrated lime (hydroxides) and burnt lime (oxides).
Loam: a soil which is made up of sand, silt and clay.
Lobe: a rounded or divided segment of a leaf.
M
Maintenance: the upkeep or care of turf.
Margin: the edge or border of a leaf or blade.
Mature: the state of full development.
Membranous: a substance which is thin, soft, pliable and often transparent or translucent.
Methylene ureas: a ureaformaldehyde resin whose structural characteristics control the solubility of nitrogen and therefore its rate of release.
Microorganism: any of a range of small-sized organisms ranging from protozoa and bacteria to fungi.
Midrib (midvein): the central or main rib or vein of a leaf.
Monocot (monocotyledon): any plant emerging from the seed with only one leaf.
Moss: a low-growing, simple plant found in shady, moist areas or turf, generally lacking in sunlight, drainage and fertility.
Mulch: a covering, such as straw, used to protect seedlings, preserve moisture and prevent erosion.
Mutation: a genetic change in an offspring which results in distinct permanent characteristics which differ from those of the parent.
Mycelium: the mass of interwoven, threadlike filaments of a fungus growing in and among grass blades.
N
NAI index: nitrogen availability index. It is the percentage of water insoluble nitrogen which becomes available to the plant in 1-4 weeks. The higher the NAI index implies a more rapid release of nitrogen.
Net venation: the veins of a broadleaf plant branching in all directions to form a net-like pattern.
Nitrification: the soil process by which nitrites are changed to nitrates through the aid of bacteria.
Nitrogen (N): one of the three major nutrients necessary for healthy plant growth. Used by the plant for chlorophyll production and plant and leaf growth.
Node: the joint where the leaf is attached to the stem.
Noxious weed: any plant which has been declared by law to be a harmful or dangerous weed.
Nutlet: a small, reproductive growth on the roots of sedges and other plants,
Nutrient: any food or plant material that nourishes or promotes plant growth,
Nymph: the immature stage in the life cycle of certain insects.
O
Open field burning: traditional method of sterilizing seed production fields by burning the top growth and thereby stimulating next year's regrowth.
Opposite: two leaves at a node growing across from one another.
Organic: any substance formed from decayed living matter.
Osmosis: an interchange of materials between two solutions which are separated by a semipermeable membrane.
Overseed: seeding into a thin, existing turf.
P
Panicle: an irregularly branched and rebranched inflorescence.
Parallel venation: principal veins of a leaf parallel to each other and to the longitudinal axis of the leaf.
Parasite: an organism which takes its food from the living tissues of a host organism.
Parthenogenesis: reproduction by eggs without fertilization by sperm.
Pathogen: an organism causing a disease.
Peat: partially decomposed organic matter entering the first stage of coal formation.
Percolation: the movement of water through the soil.
Pesticide: any chemical agent used to control pests. This would include fungicides, herbicides, insecticides, nematocides, etc.
Petiole: the stalk which supports the leaf.
PH: means "potential Hydrogen" and is used to determine the acidity or alkalinity of the soil.
Phloem: conducting tissue to the outside of a vascular bundle, notably active in moving organic compounds to regions of low concentration.
Phosphorous(P2O5): one of the three major plant nutrients necessary for healthy growth. Used in root growth, plant development and seed formation.
Photosynthesis: the process by which plants containing chlorophyll convert sunlight, carbon dioxide and water into chemical energy for their own use.
Plugging: a method of starting a turf area by inserting small cores of grasses at given intervals.
Post-emergence control: applying a herbicide which destroys a growing plant.
Potash (K2O): one of the three major plant nutrients necessary for healthy growth. Used for the overall growth.
Pre-emergence control: applying a herbicide which prevents germination or growth of a plant.
Prostrate: lying flat upon the ground.
Protoplasm: the life-giving substance of all organisms.
Pubescence: having a covering of soft, fine hairs.
Pupa: the intermediate stage of insect development between the larva and adult.
Purity: the percent, by weight, of pure seed of each component in the blend.
Pustules: a small blister-like elevation found on grass blades and generally associated with fungi.
R
Renovate: to rebuild a turf using an existing turf as the seedbed.
Residual: the length of time a chemical remains effective after an application.
Resilience: the ability of a grass blade to return to an upright position after bending.
Respiration: a process by which living plants and animals use oxygen for metabolism. This is often mistaken for inhaling or the breathing of oxygen.
Rhizome (rootstock): the underground stem which is capable of producing a new plant.
Roguing: the manual process of selectively removing off-breed plant types from seed production fields.
Root system: the underground downward growth of a plant; anchors plant to the soil and absorbs moisture and nutrients from the soil for use by the entire plant.
Root zone: the area of the soil where roots develop, grow and mature.
Rosette: a plant having a circular cluster of leaves.
Ryegrass: annual or perennial types of cool season grasses of fine and coarse textures.
S
St. Augustine: a coarse-textured, warm season grass which spreads by stolons
Salt tolerance: the ability of a plant to withstand salt water or salt-laden soil.
Sandy soil: a broad term used to indicate a soil type with the major part being 2/3 to 3/4 sand.
Saprophyte: an organism which lives on a host without taking food from the plant.
Saturation: a condition when the soil is holding its total capacity of water.
Scalp: to cut the turf from the soil, or to mow overly close, or to cut into the grass crowns.
Sclerotia: a hard, dense, compact mass of mycelium with a specialized outer coat or rind that contains spores in over-summer or over-winter periods.
Sedge: a family of plants resembling grass, but having a solid triangular stem.
Seed: the reproductive structure of a plant containing the embryo (young plant), food supply and protective coat.
Seed bed: soil that is properly tilled and prepared for seeding.
Seed coat: the outer layer of the seed structure which holds the embryo and food supply and protects the young plant until germination.
Seed count: the number of seeds in a pound.
Seedpod: a dried case or capsule containing a seed or seeds.
Segmented body: the body of an insect which is divided into several distinct parts.
Selective herbicide: a weed killer capable of controlling one type of weeds without damaging other types of plants.
Serrated: the saw-toothed pattern on the margin of a leaf.
Sessile: a condition where a plant has flowers or leaves without a stalk.
Shattering: the dropping of seeds from a seed head due to over ripening in the production field.
Sheath: the tubular lower portion of a grass leaf which surrounds the stem.
Silt: a finely textured soil or sediment usually deposited by water
Sod: the grass covered surface of the ground.
Soil: the natural medium for plant growth, usually containing inorganic and organic materials.
Soil amendments: any material added and worked into the soil to improve productivity.
Soil porosity: describes the availability of pores or cavities for nutrient and moisture storage.
Soil sterilant: a chemical which will destroy all vegetation and seeds in the soil.
Soluble: capable of being dissolved by a given liquid.
Solution: a liquid containing a dissolved substance.
Spatulate: a leaf which gradually widens from the base to a rounded end, resembling a spatula.
Species: a class of organisms having common characteristics designated by a common name.
Spike: an inflorescence on which the flowers or seeds are sessile and are arranged on any unbranched stem.
Spore: the reproductive structure of a fungus functioning as a seed.
Spray drift: the movement of airborne spray particles from the spray nozzle outside the intended contact area.
Sprigging: establishing new turf by planting stolons in the soil.
Stand: a group of plants growing together in one area.
Stem: the part of a plant which develops buds and shoots and supports a leaf or flower
Stolon (runners): a stem growing along the soil surface which is capable of taking root and starting a new plant at each node.
Stoloniferous (creeping): the spreading of plants by stolons.
Stomata: minute openings for transpiration on the surface of leaves and stems, which are opened and closed by guard cells.
Stress: a condition under which a plant suffers due to lack of moisture, food, extreme heat, or any combination of the three.
Stromata: a cushion-like, mycelial mass of tissue on or in which fructification usually occurs.
Sub-irrigation: supplying moisture to the root zone from beneath the surface.
Subsoil: the stratum of weathered material that underlies the surface soil.
Surfactant: a material that improves the emulsifying, spreading, wetting and other surface modifying properties of chemical formulations.
Swathing: the process of cutting the seed heads in the seed production fields and laying them into windrows before combining.
Symptom: a change or conditions indicating the existence of disease, injury, etc.
Synthetic: any material created by artificial means.
Syringing: adding moisture to a plant through the leaf to reduce or prevent water loss and cool the plant.
Systemic pesticide: a chemical which is absorbed by the plant roots, and thus, internally prevents disease or insect damage.
T
Taproot: a long, single, vertical-growing root.
Tensiometer: instrument used for measuring the pressure of soil water.
Terminal: the end of a branch or stem.
Thatch: the accumulated layer of undecomposed plant parts between the living plant parts and the soil surface.
Tillers: a sprout or stalk that forms its own leaves and originates at the base of the parent plant.
Tolerance: degree to which a plant endures a stress.
Top dressing: a prepared mixture spread over, and worked into the turf. It is apt to be formulated of sand, compost, organic matter and fertilizer.
Topsoil: the upper layer of soil, which ideally, contains rich, fertile, organic matter.
Trace elements: small amounts of certain elements essential for healthy plant growth.
Translocate: to move about in the plant in solution.
Transpiration: the exchange of gases and water vapor between the plant and the atmosphere.
Turf: the upper stratum of soil bound by grass and plant roots into a thick mat.
Turgidity: the expansive force in a blade, caused by the presence of water, permitting it to stand erect.
U
Urea: a water soluble nitrogen compound, used in fertilizers, made from carbon dioxide and ammonia.
V
Vascular system: transports the nutrients and water to all parts of the plant.
Veins: part of the vascular system which forms the framework of the leaf.
Venation: the arrangement of the veins in a leaf.
Vermiculite: a micaceous mineral silicate which expands with heat and has absorption qualities.
Vertical mowing: cutting perpendicular into the turf to lift or cut stolons to control grain, or to remove thatch.
Viable: a seed which is capable of germinating.
Vining: plants whose stems creep along the surface of the ground.
Volatilize: the state of changing from a liquid to a gas at ordinary temperatures when exposed to the air.
W
Weed: any plant growing where it is not wanted.
Wet wilt: the inability of a plant to absorb enough moisture through the roots to equal the rapid loss of moisture through the leaves.
Whorl: a circular arrangement of three or more leaves or flowers around a single plant.
Winterkill: injuries of turf resulting from environmental stresses during the cold part of the year.
X-Y-Z
Xylem: the inner conducting layer of a bundle, through which bulk water is removed.
Zoysia: a warm season grass which spreads slowly by stolons and rhizomes.
