ABDOMEN -- The third division of the insect body.
ABSORPTION -- The process by which herbicides are taken into plants,
by roots or foliage (stomata, cuticle, etc.)
ACARICIDE -- A pesticide used to kill mites (an insect relative).
ACID SOIL -- A soil with a pH value of less than 7.0.
ACTIVE INGREDIENT (AI) -- The amount of actual pesticide in
ADJUVANT -- A chemical added to a pesticide formulation or mixture
to improve its effectiveness.
ADSORPTION -- The adhesion of herbicide spray droplets to the
ADULT -- An insect which is fully grown and sexually mature,
or in the winged stage.
AERATION, MECHANICAL -- See Cultivation.
ALKALINE SOIL -- A soil with a pH value greater than 7.0.
ALLELOPATHIC -- Substance produced by one plant which injures
or suppresses the growth of another.
ALTERNATE -- Leaves arranged singly at different heights and
on different sides of the stem.
AMENDMENT, PHYSICAL -- Any substance added to the soil for the
purpose of altering physical conditions (sand, calcined clay, peat, etc.).
ANNUAL -- A plant that completes its life cycle within one year,
ANTHER -- The pollen-bearing part of a stamen.
ANTIDOTE -- A remedy used to counteract the effects of a poison.
APICAL MERISTEM -- Terminal growing point.
ANTHRACNOSE -- Term describing a fungal disease having characteristic
necrotic lesions on leaves.
APPLICATION RATE -- The amount of pesticide formulation applied
to a given area.
AROMATICS -- Compounds derived from the hydrocarbon benezene
ATROPHY -- Under-development of a tissue due to a decrease in size of the individual cells. (See HYPERTROPHY.)
AURICLE -- Claw-like appendages occurring in pairs at the base
of the leaf blade or at the apex of the leaf sheath.
AWN -- Hairlike projections, usually extending from the mid-nerve
or section of a grass flower.
AXIL -- Upper angle formed between a leaf (or spikelet) and
the stem axis.
BACTERICIDE -- Material that will kill bacteria.
BACTERISTAT -- Material that inhibits bacterial growth, but does not kill the bacteria.
BACTERIUM (singular, bacteria) -- A microscopic, unicellular
organism, lacking chlorophyll and reproducing by simple cell division.
BAND APPLICATION -- An application of spray or dust to a continuous
restricted area such as in or along a crop row rather than over the entire
BASAL TREATMENT -- Applied to encircle the stem of a plant above
and at the ground such that foliage contact is minimal. A term used mostly
to describe treatment of woody plants.
BASAL WHORL -- Groups of leaves attached at the same point at
the base of a plant.
BENCH SETTING -- The height at which the bed knife of a mower
is set above a firm, level surface.
BIENNIAL -- A plant that completes its growth in two years.
The first year, it produces leaves and stores food; the second year, it
produces fruits and seeds.
BIOLOGICAL CONTROL -- Control of pests by means of living organisms
such as predators, parasites, and disease-producing micro-organisms.
BLADE -- The flattened portion of a grass leaf located above
the sheath; the portion of the leaf that grows away from the stem.
BLEND -- A combination of two or more cultivars of a single
BROADCAST TREATMENT -- Application of a herbicide over an entire
BUG -- An insect belonging to the order Hemiptera.
BUNCH-TYPE GROWTH -- Plant development at or near the soil surface
without production of rhizomes or stolons.
CANKER -- A diseased or dead area in the bark and wood of trees
or shrubs. Characterized by a drying out of the tissues.
CARBAMATE INSECTICIDE -- A synthetic compound derived from carbamic
acid. Carbamate insecticides are contact killers with relatively short-lived
effects. Examples are carbaryl and bendiocarb.
CARRIER -- The liquid or solid material added to a chemical
compound to facilitate its storage, shipment, or use in the field. CULM
Stem of a grass plant.
CASTINGS, EARTHWORM (WORMCASTS) -- Soil and plant remains excreted
by earthworms that are deposited on the turf surface or in the burrow;
forms a relatively stable soil granule that can be objectionable on closely
CATERPILLAR -- Usually applies to the larvae of the Lepidoptera,
but the larvae of sawflies in the Hymenoptera are also caterpillarlike.
CELL -- The unit of plant and animal structure; it consists
of a small bit of protoplasm which, in plants, is usually surrounded by
a cell wall.
CHLOROSIS (Adj. chlorotic) -- A yellow to white or gray condition
of normally green plant tissue resulting from the partial to complete destruction
of chlorophyll. Chlorosis is a common symptom of iron deficiency.
CLAW -- Sharp, hollow appendages on the end of the last tarsal
segment of insects, used for clinging to objects.
COLEOPTILE -- Protective sheath of an embryonic shoot.
COLLAR -- A light-colored band at the junction of the leaf blade
and sheath on the outside of the leaf.
COLORANT -- A paintlike material, usually a dye or pigment,
applied to (a) brown warm-season turf grasses that are in winter dormancy;
or (b) brown cool-season turf grasses that are in summer dormancy; or (c)
turfs that have been discolored by environmental stress, turf-grass pests,
or the abuse of human beings. Its purpose is to maintain favorable green
COMPATIBLE -- Quality of two compounds that permits them to
be mixed without effect on the properties of either.
COMPLETE FLOWER -- One possessing all floral parts -- sepals,
petals, stamens and pistils.
COMPOST -- A mixture of organic residues and soil that has been
piled, moistened, and allowed to decompose.
COMPOUND LEAF -- One divided into two or more distinct leaflets.
CONCENTRATION -- The amount of active material in a given volume.
Specifications for concentration of herbicides should be on the basis of
pounds per unit volume of diluent.
CONTACT PESTICIDE -- A pesticide that kills on contact.
COOL-SEASON TURF GRASS -- Turf-grass species adapted to favorable
or optimal growth during cool portions (60 to 75 degrees F.) of the growing
CORE AERIFICATION -- A method of turf cultivation in which soil
cores are removed by hollow tines or spoons to control soil compaction
and to aid in the penetration and distribution of pesticides and water.
CORNICLES -- Dorsal, tubular appendages on the posterior part
of the abdomen of certain aphids.
CORTEX -- Outside of conducting tissue (xylem and phloem) to
CORTICAL -- Of or pertaining to the cortex.
CRAWLER -- An immature stage of an adelgid or scale insect --
the active, crawling stage.
COTYLEDON LEAVES -- The first leaf, or pair of leaves, of the
embryo of seed plants.
CROWN -- The point where stem and root join in a seed plant.
CULTIVAR -- A group of cultivated plants distinguished by any
characteristics (morphological, physiological, cytological, etc.)
which, when reproduced sexually or asexually, retain their distinguishing
features; a cultivated variety.
CULTIVATION -- Applied to turf, cultivation refers to working
of the soil and/or thatch without destruction of the turf, such as coring,
slicing, spiking, or other means.
CURCULIO -- Beetles of the suborder Rhynchophora which have
slender snouts curving downward and backward, with chewing mouthparts at
DAMAGE THRESHOLD LEVEL -- The lowest pest population density at
which damage occurs.
DAMPING-OFF -- Decay of seeds in the soil or young seedlings
before or after emergence. Most evident in young seedlings that suddenly
wilt, topple over, and die of rot at the stem base.
DESICCATION -- Drying out.
DETHATCHING -- Removing excessive thatch from a turf-grass area
by hand-raking or with various types of machinery equipped with vertical
knives or tines.
DICOT -- Plant having two cotyledons in the seed, as in broadleaf
DIRECTED APPLICATION -- A pesticide directed onto weeds or soil
in a way that avoids contact with the turf grass.
DORMANCY -- State of inhibited germination of seeds or growth
of plant organs; a state of suspended development.
DORMANT SPRAY -- Spray applied during the dormant season, when
plants are inactive.
DRIFT -- The movement of material by air outside the intended
target area during or shortly after application.
ECOLOGY (Applied to plant pathology) -- The study which deals with
the effect of environmental factors such as soil, climate and culture on
the occurrence, severity and distribution of plant diseases.
ECONOMIC-INJURY LEVEL -- The lowest population density of pests
that will cause economic damage.
EELWORMS -- Nematodes.
EMERGED -- The emergence of the adult from the cocoon, pupal
case or nymph.
EMERGENCE -- Appearance of the first part of the crop plant
through the ground.
EMULSIFYING AGENT -- A material which facilitates the suspending
of one liquid in another.
EMULSION -- A mixture in which one liquid is suspended in tiny
globules in another liquid; for example, oil in water.
ENTOMOLOGY- - The science which includes all phases of studies
ENVIRONMENT -- The external conditions and influences surrounding
ERADICANT -- A fungicide or other chemical used to eliminate
a pathogen from the host or environment.
ERIOPHYID -- Any of a group of tiny mites characterized by having
a slender body and two pairs of legs, rather than four.
EVAPOTRANSPIRATION -- Total loss of moisture through the combined
process of evaporation and transpiration.
EXOSKELETON -- Hard or resistant outside covering of an insect.
EXUDATE -- Material that has been forced out of infected area.
FACULTATIVE -- Opposite of obligate.
FAMILY -- A unit of classification which includes a number of
genera agreeing in certain characteristics which cause them to appear related
FLAIL MOWER -- A mower that cuts turf by high-speed impact of inverted
T-blades rotating in a vertical cutting plane relative to the turf surface.
FLORET -- A grass flower enclosed by a lemma and palea.
FLOWABLE -- A finely ground wettable-powder formulation sold
as a thick suspension in a liquid. Flowables require only moderate agitation
and seldom clog spray nozzles.
FOLIAR APPLICATION -- Application of a herbicide to the leaves
or foliage of plants.
FOLIAR BURN -- Injury to shoot tissue caused by dehydration
due to contact with high concentrations of chemicals, such as certain fertilizers
FORMULATION -- The form in which a pesticide is offered for
sale to the user (as emulsifiable concentrate, wettable powder, granule,
dust, oil solution, etc.). Includes both the active and inert ingredients.
FRASS -- Wood fragments mixed with excrement produced by an
FUMIGANT -- A pesticide that, as a gas, kills destructive micro-organisms,
animals and plants.
FUNGAL -- Relating to fungi.
FUNGICIDE -- Material that will kill fungi.
FUNGUS -- A thallus plant (that is, one not
differentiated into root, stem and leaves) devoid of chlorophyll.   Some
fungi attack other plants and cause plant diseases such as rusts, smuts
mildews, wilts, and leaf spots.
GALL -- An unusual enlargement on some portion of a plant. An abnormal
growth of plant tissue stimulated by insect or pathogen attack.
GENUS (plural, genera) -- A group of species which have many
characteristics in common. A family consists of one to many genera.
GLUMES -- A pair of bracts usually present at the base of a
GRADUAL OR DIRECT METAMORPHOSIS -- Metamorphosis with three
stages, namely egg, nymph and adult, as in the growth of grasshoppers.
GRANULAR -- A dry formulation of herbicide and other components
in particles, generally less than ten cubic millimeters in size.
GRANULES -- A formulation in which the pesticide is attached
to particles of an inert carrier, such as clay or ground corncobs. Granules
range in size from 15 to 20 mesh.
GRASS -- Any plant that is a member of the family Gramineae
GROUND COVER -- Low-growing, non-grass plants used to cover
the soil in areas where mowing is impractical or turf will not grow.
GROWTH STAGES -- (1) Tillering stage -- when a plant produces
additional shoots from a single crown, as in wheat. (2) Jointing stage
-- when the internodes of the stem are elongating. (3) Boot stage -- when
the seedhead of a plant begins to merge from the sheath, usually
applied to grain crops.
GRUB -- Larvae of certain beetles, especially the Scarabaeidae
and Rhynchophora, and also some flies -- for example, white grubs and cattle
HABITAT -- Usually, the environment in which an insect lives.
HAZARD -- The likelihood that an injury will result from the
use of a pesticide. A hazard constitutes both toxicity and exposure.
HEAD -- The first division of the insect body.
HERBACEOUS -- Soft, lacking woody tissue.
HERBICIDE -- A chemical that is generally toxic to plants without
regard to species. Toxicity may vary with dosage, method of application,
HONEYDEW -- A sweet, sticky fluid excreted by aphids, certain
scales, mealybugs, whiteflies and leafhoppers.
HOST -- Any plant or animal invaded by a parasite and from which
the parasite obtains its food.
HUMUS -- The organic fractions of soil in which decomposition
is so far advanced that its original form canít be distinguished.
HYBRID -- Product of a cross between individuals of unlike genetic
HYDROSEED -- To apply seed in a water mixture by pumping through
a nozzle that sprays the mixture onto a seedbed. The water mixture may
also contain amendments such as fertilizer and mulch.
HYPERPLASIA -- An abnormal development of tissues due to an
increase in the number of cells. (See HYPERTROPHY.)
HYPERTROPHY -- An abnormal development of tissues due to an
increase in the size of individual cells. (See ATROPHY)
HYPHA (plural, hyphae) -- One of the filaments which collectively
form the mycelium of a fungus.
HYPOPLASIA -- Under-development of growth due to a decreased number of cells.
INCUBATION PERIOD -- The period between the time the inoculum is
introduced onto the host and the time when the diseased condition becomes
INERT INGREDIENTS -- Ingredients of a pesticide formulation that
are not active, such as water, sugar, dust, wetting and spreading agents,
emulsifiers, propellants, etc.
INFECTION -- The process of gaining entrance and becoming established
as a parasite.
INFECTION COURT -- The specific area on a plant where
a pathogen gains entrance to the host.
INFECTIOUS DISEASE -- A disease caused by a pathogen that multiplies
and can be transmitted from plant to plant.
INFEST -- To overrun.
INFLORESCENCE -- The flowering portion of a shoot including
the spikelets, and any supporting axis or branch system.
INOCULUM -- That portion of a pathogen which is transferred
to a host. It usually consists of spores, bacteria, or mycelial fragments.
INOCULATION -- The process of transferring inoculum to a host.
INSECT -- A term used to describe numerous small invertebrate
(no backbone) animals, such as true insects, spiders, mites, ticks, centipedes
and millipedes. In the adult stage, true insects usually have six legs,
three body divisions, and wings.
INSECTA -- One of the classes of animals in the Phylum Arthropoda.
They have three body divisions and six legs, and may or may not have wings. The true insects.
INSECTICIDE -- A pesticide used to prevent, destroy, repel,
mitigate or attract insects and their relatives.
INSTAR -- The stage of an insect between molts.
INTEGRATED PEST MANAGEMENT (IPM) -- Controlling pest populations
through chemical, physical, cultural, biological and regulatory methods.
INTERNODE -- Portion of a stem between the nodes or growing
LABEL -- A printed statement affixed to the pesticide container
by the manufacturer, listing the contents, directions for use, and precautions.
A pesticide label must be approved and registered by the U.S. Environmental
Protection Agency and the Utah Department of Agriculture.
LARVA (plural larvae) -- The immature or worm stage (caterpillar,
maggot, grub) of an insect that passes through four stages (egg, larva,
pupae, adult) in its development. Caterpillars,
maggots and grubs are kinds of larvae.
LATERAL SHOOT -- A shoot originating from a vegetative bud in
the axil of a leaf or from the node of a stem, rhizome or stolon.
LEACHING -- The washing of soluble materials from the soil by
the downward movement of water (deep irrigation or rain).
LEAFLET -- Secondary division of the compound leaf.
LEATHERY WING -- Somewhat thickened but flexible front wings,
found on grasshoppers and earwigs.
LESION -- A diseased region, usually sunken or discolored.
LIFE CYCLE -- Span of time between fertilization of the egg
and the death of the individual.
LIGULE -- A membranous or hairlike appendage inside the grass
leafs at the junction of the leaf and blade.
LOCAL INVASION -- That involving only a localized area of the
plant. (See Systemic Invasion.)
LOCALIZED DRY SPOT -- A dry spot of sod amid normal, moist turf
that resists rewetting by normal
irrigation and rainfall. It is associated with many factors, including
thatch, fungal activity, shallow soil over buried
material, or elevated sites in the terrain.
MAGGOT -- Larvae of the higher diptera, especially of some families
related to houseflies.
MELTING OUT -- A disease (primarily of Kentucky bluegrass) caused
by the fungus Drechslera poae. It is characterized by the appearance
of dark leaf spots, often followed by the killing of irregular areas of
MICRO-ORGANISM -- Tiny living organism such as a bacterium,
fungus, nematode, protozoan or virus.
MIDRIB -- The central vein of a grass leaf, extending from the
stem to the leaf tip.
MOLD -- Any fungus with conspicuous mycelium or spore masses;
often saprophytic. Grows most commonly on damp or decaying matter and on
the surface of plant tissues.
MOTTLE -- An irregular pattern of light and dark areas.
MOUTHPARTS -- The name given to all parts of the mouth when
taken together (collectively).
MOWING FREQUENCY -- The number of times a turf-grass area is
mowed per week, month, or growing season. (The reciprocal of mowing frequency
is mowing interval -- the number of days, weeks, etc., between successive
MOWING HEIGHT -- The distance above the ground surface at which
the turf grass is cut during mowing.
MOWING PATTERN -- The pattern of back-and-forth travel while
mowing turf. Patterns may be changed regularly to distribute wear and compaction,
to avoid creating "grain," and to create visually aesthetic effects, especially
for spectator sports.
MULCH -- Any non-living material (straw, sawdust, leaves, plastic
film, etc.) spread on the soil surface to protect it.
MUMMY -- A dried, diseased fruit.
MYCELIUM (plural, myulin) -- Collective term for a group or
mass of hyphae or fungus filaments.
NECROSIS -- A type of pathological condition marked by the rapid
destruction of cell structures and a consequent prompt death of the protoplasts:
the death of a tissue.
NEMATICIDE -- A material that will kill nematodes.
NEMATODES -- Generally microscopic, unsegmented roundworms that
usually live free in moist soil, water, or decaying matter, or as parasites
of plants and animals.
NITRIFICATION -- Formation of nitrates and nitrites from ammonia
by soil micro-organisms.
NOCTURNAL -- Active at night.
NODE -- The joint of a stem; the region of attachment of leaves
on a stem.
NON-INFECTIOUS DISEASE -- A disease (or disorder) caused by
unfavorable growing conditions and which canít be transmitted from
plant to plant.
NON-SELECTIVE HERBICIDE -- A chemical that is generally toxic
to plants, without regard to species. Toxicity may vary with dosage,
method of application, etc.
NOZZLE -- A device for metering and dispersing a spray solution.
NYMPH -- The immature stage (resembling an adult) of an insect
that passes through three stages (egg, nymph and adult) in its development.
OBLIGATE -- Necessary; essential; (of parasitism) necessary parasite,
capable of living on living tissue.
OBLIGATE PARASITE -- Organisms that can live only as parasites.
OBLIGATE SAPROPHYTE-- Organisms that can live only as saprophytes.
OPPOSITE -- Leaves attached precisely opposite each other on a stem.
ORGANIC MATTER -- Plant or animal material capable of undergoing
breakdown and resynthesis (in the soil). ORGANIC-PHOSPHOROUS INSECTICIDE
-- A synthetic compound derived from phosphoric acid. Organic-phosphorus
insecticides are primarily contact killers with relatively short-lived
effects. They are decomposed by water, pH extremes, and high temperatures
and micro-organisms. Examples are malathion, diazinon, chlorpyrifos, aspon,
phorate, isofenphos, trichlorfon, dimethoate and fenthion.
ORIFICE -- An opening in a nozzle tip, duster, or granular applicator
through which the spray, dust or granules flow. OVERSEED -- To seed
onto an existing turf, usually with temporary turf grass, to provide green,
active grass growth during dormancy of the original turf (usually
a warm-season turf grass).
OVIPOSITOR-- A tubular structure on female insects for depositing eggs.
PALMATE -- Three or more lobes, leaflets or veins arising from one
PANICLE -- Type of inflorescence in which the spikelets are
not directly attached to the main axis.
PARASITE -- An organism (fungus, bacterium, virus, nematode,
etc.) that obtains its food from another organism. An obligate parasite
is one that can develop only in living tissues (e.g., a virus or plant-parasitic
PARASITIC INSECT -- An insect that lives in or on the body of
PARTICLE DRIFT -- Sprays which are carried away from the application
area by air movements.
PATHOGEN -- An organism or agent capable of causing disease.
PATHOGENICITY -- Ability of an organism to produce disease.
PATHOLOGY -- The study of disease.
PELLET -- A dry formulation of herbicide and other components
in discrete particles usually larger than ten cubic millimeters.
PERENNIAL -- A plant that lives for three years or more under
normal growing conditions.
PERSISTENT HERBICIDE -- A herbicide which, when applied at the
recommended rate, will harm susceptible crops planted in normal rotation
after harvesting the treated crop, or which interferes with regrowth of
native vegetation in non-crop sites for an extended period of time.
PESTICIDE -- A material that will kill, reduce, ease the effects
of, or control weeds, diseases, insects, rodents, and other pests.
PETAL -- Portion of a flower surrounding the stamen and pistil;
sometimes colorful or showy.
PETIOLE -- The stalk of a leaf.
pH SOIL -- A numerical measure of the acidity or hydrogen ion
activity of a soil. A pH of 7 is neutral; above 7 is basic (alkaline);
below 7 is acidic.
PHEROMONE -- A biochemical substance produced by insects to
attract within the same species through the sense of smell. PHLOEM
-- The food-conducting tissue of vascular plants.
PHLOEM -- Food-conducting tissues in plants.
PHOTOSYNTHESIS -- Process by which carbohydrates are produced
from carbon dioxide, water, light energy in chlorophyll-containing plants.
PHYSIOLOGY -- The study of processes, activities and phenomena
related to life.
PHYTOTOXIC -- A pesticide that is injurious or poisonous to
PIERCING-SUCKING MOUTH PARTS -- Mouth parts adapted for penetrating
and sucking juices from tissues.
PINNATE -- Having branches, lobes, leaflets or veins; attached
or arranged on two sides of a stem.
PISTIL -- Female structures of a flower, usually consisting
of an ovary and one or more stigmas and stiles.
PLANT-GROWTH REGULATOR -- A substance used for controlling or
modifying plant-growth processes without appreciable phytotoxic effect
at the dosage applied.
POST-EMERGENCE HERBICIDE -- A herbicide that is applied after
emergence of the crop or weed.
POST-EMERGENCE TREATMENT -- Treatment made after the crop plants
POSTERIOR -- Hind part.
PREDATORY OR PREDACEOUS INSECT -- An insect that feeds on other
PRE-EMERGENCE HERBICIDE -- A herbicide that is applied before
emergence of the crop or weed.
PRE-EMERGENCE TREATMENT -- Treatment made after a crop is planted
but before it emerges.
PRE-PLANT HERBICIDE -- A herbicide that is applied before the
crop is planted.
PROLEGS -- Fleshy abdominal legs of certain insect larvae.
PROTECTANT -- A pesticide used to prevent infection by an organism.
PSI -- Pressure; measured in pounds per square inch.
PUPA (plural, pupae) -- An intermediate stage between the full-grown
larva and the adult in insects with complete metamorphosis; usually inactive.
PUPATE -- To change from the larval stage to the pupal stage.
PURE LIVE SEED (PLS) -- Percentage of the content of a seed
lot that is pure and viable.
PUSTULE -- A small, raised blister or pimplelike swelling on the surface of a leaf that
may rupture the epidermis to expose the causal agent (e.g., rust or smut).
RACEME -- Type of inflorescence in which the spikelets are borne
on short stems (pedicels) attached directly to the main axis.
RASPING -- Sucking mouth parts fitted with structures for roughening
plant tissues, and also provided with modification of structures for sucking
RATE AND DOSAGE -- These terms are synonymous. "Rate" is the
preferred term. Usually refers to the amount of active-ingredient material
(such as 2,4-D acid equivalent) applied to a unit area (such as one acre),
regardless of percentage of chemical in the carrier.
RECUPERATIVE POTENTIAL -- The ability of a turf grass to recover
from injury through vegetative growth.
RE-ESTABLISHMENT -- Rebuilding a lawn by complete removal of
any existing turf, followed by site preparation and planting.
RENOVATION, TURF -- Turf improvement involving replanting into
existing live and/or dead vegetation.
RESIDUAL -- The property of a pesticide for persisting after
application in amounts sufficient to kill pests for several days to several
weeks or even longer.
RESIDUE -- The amount of pesticide present following application.
RESISTANT SPECIES -- Pests that survive relatively high rates
of pesticide application.
RESTING SPORE -- A spore, usually thick-walled, which may remain
alive in a dormant state for months or years, later germinating and being
capable of causing the infection.
RHIZOME -- Underground stem capable of sending out roots and
ROGUE -- Remove; pull out.
ROOT ZONE -- The upper six to eight inches of soil, in which
most of the turf-grass roots are concentrated.
ROSETTE -- A basal, circular cluster of leaves not separated
by evident internodal-stem elongation.
RUNOFF -- Pesticide material that is carried away from an area
by the flow of surface water. Also used to describe the rate of application
to a surface -- "spray to a rate of runoff."
RUST -- Originally, the summer or uredinial stage of the Uredinales
on grasses; now used either for the fungus itself in any of its stages
or the disease caused by any of the stages.
SALINITY -- An excess of soluble salts in the soil; turf-grass growth
and quality are impaired.
SAPROPHYTE -- An organism that obtains its food from dead organic
matter, as opposed to a parasite that feeds on living tissue. See also
SCALD -- A condition that exists when a turf grass collapses
and turns brown under conditions of intense sunlight; high water temperatures;
and standing water, usually of a relatively shallow depth.
SCALE INSECTS -- A group of insects characterized as having
a hard, convex covering over their body with no visible appendages or segmentation.
Usually small, ranging from one to five millimeters in length or diameter.
SCALP -- To remove an excessive quantity of functioning green
leaves at any one mowing; results in a shabby, brown appearance caused
by exposing crowns, stolons, dead leaves, and even bare soil.
SCLEROTIUM (plural, sclerotia) -- A hard, dense, compact mass
of mycelia serving as a resting body.
SCUM -- The layer of algae on the soil surface of thinned
turfs; drying can produce a somewhat impervious layer that can impair subsequent
SECONDARY INFECTIONS -- Those infections initiated (usually
during the summer) by inocula from primary or other secondary infections
without an interposed resting or dormant period.
SEDGE -- A grasslike plant with triangular stems that spreads
by rhizomes and overwinters as tubers.
SEED BLEND -- A combination of seeds of two or more cultivars
of the same turf-grass species.
SEEDHEAD -- Floral development; in the case of grasses, usually
a fruiting cluster or spike.
SELECTIVE HERBICIDE -- A chemical that is more toxic to some
plant species than to others.
SELECTIVITY -- The ability of a pesticide to kill some pests
but not others.
SHEATH -- The tubular, basal portion of the leaf that encloses
SHOOT DENSITY -- The relative number of shoots per unit area.
SIGN -- The structure of the pathogen itself.
SKELETONIZE -- To remove the green portions of a leaf, leaving
only the veins, midrib, and a transparent membrane.
SLICING -- A method of turf cultivation in which rotating flat
tines slice intermittently through the turf and soil.
SLIME MOLD -- Primitive organisms whose plasmodium "flows" over
low-lying vegetation like an amoeba.
SLIT-TRENCH DRAIN -- A narrow trench (usually five to ten centimeters
wide) backfilled to the surface with a porous material such as sand, gravel,
or crushed rock. Used to intercept surface or lateral subsurface drainage
SLOWLY AVAILABLE FERTILIZER -- Designates dissolution less than
that obtained for completely water-soluble fertilizers. May involve compounds
that dissolve slowly, materials that must be decomposed microbiologically,
or soluble compounds coated with substances highly impermeable to water.
Used interchangeably with delayed release, controlled
release, controlled availability, slow-acting and metered release.
SLUGLIKE -- Larvae of sawflies and of some moths which resemble
SNOUT BEETLE -- A weevil -- an insect with a long proboscis
or snout bearing chewing mouthparts.
SOD -- Plugs, squares or strips of turf grass, with adhering
soil which are used in vegetative planting.
SOIL APPLICATION -- A herbicide applied primarily to the soil
surface rather than to vegetation.
SOIL MODIFICATION -- Alteration of soil characteristics by adding
soil amendments; commonly used to improve physical conditions.
SOIL PROBE -- A cylindrical soil-sampling tool with a cutting
edge at the lower end.
SOIL STERILANT -- A material which renders the soil incapable
of supporting plant growth. Sterilization may be temporary or almost permanent.
SOIL STERILIZATION -- Treating soil by heat or chemicals to
kill living organisms.
SOLUBILITY -- The maximum amount of a liquid or solid that will
dissolve in a liquid.
SOLUBLE POWDER -- A powder formulation that dissolves and forms
a solution in water.
SOLUTION -- A mixture in which a pesticide is dissolved in a
liquid. The pesticide is evenly dispersed as individual molecules among
the molecules of liquid.
SOOTY MOLD -- A dark, often black, fungus growing on insect
SPECIES -- The primary biological unit which mates with others
of its kind, producing fertile offspring which resemble each other and
their parents as much as the progeny of a single set of parents.
SPIKING -- A method of turf cultivation in which solid tines
or flat, pointed blades penetrate the turf and soil surface.
SPIRACLE -- The external opening of the respiratory organ of
SPOON, CORING -- A method of turf cultivation by which curved,
hollow, spoonlike tines remove soil cores and leave a hole or cavity in
SPORE -- In fungi, a one-celled structure formed by mycelium
and serving as an agent of propagation.
SPOT TREATMENT -- A herbicide applied over one or more small
areas of a whole unit; for example, treatment of patches of weeds within
a larger field.
SPRAY DEPOSIT -- The amount of wet pesticide initially deposited
per acre of plant or other surface.
SPRAY DRIFT -- The movement of airborne spray particles from
the spray nozzle beyond the intended contact area.
SPREADER -- Material added to a spray preparation to improve
contact between the chemical and the plant surface.
SPRIG -- A single turf-grass stem (stolon, rhizome or tiller),
usually with some attached roots, used in vegetative propagation.
SPRIGGING -- Vegetative planting by placing stolons, rhizomes
or tillers in furrows or small holes.
STAND -- The number of established individual shoots per unit
STEMMOTHER -- In aphids, the form that hatches from the overwintering
egg and gives rise to the series of summer generations which reproduce
STOLON -- An elongated horizontal stem (or shoot) that grows
above the soil and roots at the nodes. It is used to propagate certain
STOMA (pl. stomata) -- A tiny opening in the epidermis of a
leaf or stem through which gases are exchanged.
STOMACH POISON -- A poison, sprayed or dusted on the food of
insects, which kills the insect when it eats the food.
STOMATA (plural, stoma) -- Small openings or pores on the surface
of leaves or stems.
STOOL -- To throw out shoots; to tiller.
STREAK -- Necrosis along vascular bundles in leaves or stems
SUBGRADE -- The surface grade of a turf site before the addition
SURFACTANT -- A material that reduces surface tension between
two unlike materials, such as oil and water. A spreader or wetting
agent used to increase coverage of the surface being sprayed.
SUSCEPTIBLE SPECIES -- Pests readily killed by relatively low
rates of pesticide application.
SUSPENSION -- A mixture in which the pesticide in a solid form
(tiny particles) is suspended in water.
SYMPTOM -- An outward, visible sign of a diseased condition.
SYNERGISM -- The action of two pesticides that produces a greater
cumulative effect when the pesticides are used together than when they
are used individually.
SYRINGE -- To spray turf with small amounts of water, usually
on a hot, dry, windy day, to reduce water loss (transpiration).
SYSTEMIC CHEMICALS -- Chemicals that enter the plant and move
from the point of contact.
SYSTEMIC INVASION -- Micro-organisms that enter plants and penetrate
or move throughout the plant.
SYSTEMIC PESTICIDE -- A pesticide absorbed by treated plants
or animals and translocated (moved) to most tissues.
TAPROOT -- The primary descending root of a plant.
TAXONOMIST -- A scientist especially trained in the classification
of plants or animals.
THATCH -- A tightly intermingled layer of undecomposed or partially
decomposed organic residues situated above the soil surface and usually
below the green portions of the turf.
THATCH CONTROL -- The process of (a) preventing excessive thatch
accumulation by cultural manipulation and/or (b) reducing excess thatch
from a turf by either mechanical or biological means.
THORAX -- The middle region of an insect's body, where the legs
and wings are attached.
TILLER -- A lateral stem (or shoot), usually erect, which develops
from the central crown.
TOLERANCE -- The amount of pesticide deemed safe and permitted
by law on an agricultural product.
TOPDRESSING -- A prepared soil mix added to the turf surface;
usually incorporated into the soil by raking or irrigating.
TOTAL VEGETATION -- Application of single or multiple herbicides
at once or in sequence to provide pre- emergence and/or post-emergence
control of all plants. The term usually refers to non-crop areas.
TOXICITY -- The capacity of a pesticide to cause harm to a living
TRANSITIONAL CLIMATIC ZONE -- The suboptimal zone between temperate
and subtropical climates.
TRANSLOCATED HERBICIDE -- A herbicide moved within the plant.
Translocated herbicides may move either in the phloem or xylem, but the
term is often used to refer to herbicides moved in the phloem.
TRANSMISSION -- Spread of virus or other pathogens from plant
TUBER -- A swollen, usually underground stem with numerous buds.
TUMOR -- An abnormal, functionless swelling or protuberance.
TURF-GRASS COMMUNITY -- An combination of individual turf-grass
plants that have mutual relationships with the environment and individual
UREA FORMALDEHYDE -- A synthetic, slowly soluble nitrogen fertilizer
consisting mainly of methylene-urea polymers of different lengths and solubilities;
formed by reacting urea and formaldehyde.
VAPOR DRIFT -- The movement of chemical vapors from the area of
application. Some herbicides, when applied at normal rates and normal temperatures,
have a vapor pressure high enough to cause them to change into vapor form;
this may cause serious injury to susceptible plants away from the site
of application. Note: Vapor injury and injury from spray drift are
often hard to tell apart.
VARIETY -- A subspecies or a near relative with minor differentiations.
VASCULAR -- Pertaining to conductive (xylem and phloem) tissue.
VECTOR -- An organism able to transmit a pathogen.
VEGETATIVE PROPAGATION -- asexual propagation using pieces of
vegetation, such as sprigs or sod pieces.
VEINATION -- The arrangement of veins in a leaf.
VERTICAL MOWER -- A mechanical device whose vertically rotating
blades cut into the face of a turf for the purpose of reducing thatch,
grain, and surface compaction.
VIRULENT -- Highly pathogenic.
VIRUS -- A sub-microscopic entity (parasite) capable of producing
mosaics, ringspots, flower-breaking, growth malformation, and other plant
diseases. Viruses are capable of reproducing only in living plant or animal
VOLATILE -- Quality which makes a compoun devaporate or vaporize
(change from a liquid to a gas) at ordinary temperatures on exposure to
WWARM-SEASON TURF GRASS -- Turf-grass species adapted to an optimal
growth during warm portions (80 to 95 degrees F.) of the growing season.
WATER-SOAKED -- Pertaining to plants or lesions that appear
wet, dark, and usually sunken and translucent.
WEED -- Any plant growing in a place where it is not wanted.
WEEVIL -- Small beetles with a snout in the suborder Rhynchophora.
WETTABLE POWDER -- A powder formulation containing a wetting
agent that causes the powder to form a suspension in water.
WETTING AGENT -- A compound which, when added to a spray solution,
causes it to spread over and wet plant surfaces more thoroughly.
WILT -- Limpness and drooping of plant parts caused by insufficient
water in the plant.
WIND BURN -- Death and browning most commonly occurring on the
uppermost leaves of semi-dormant grasses; caused by desiccation. See also
WING MEMBRANE -- The thin, membranous portion of the wings lying
between the veins.
WINTER ANNUAL -- An annual plant that usually initiates growth
in the fall, lives over winter, and produces seed the following spring.
WINTER DESICCATION -- The death of leaves or plants by drying
during winter dormancy.
WINTERKILL -- Any injury to turf-grass plants that occurs during
the winter period.
WINTER OVERSEEDING -- Seeding cool-season turf grasses over
warm-season turf grasses at or near their start of winter dormancy, practiced
in subtropical climates to provide green, growing turf during the winter
period, when the warm-season species are brown and dormant.
WITCHES'-BROOM -- An abnormal cluster of twigs around a common
focus or a brush-like growth of small branches on trees and shrubs.
XXYLEM -- Water-conducting tissue in plants.
ZZONATE -- Targetlike; appearing in concentric rings.