Glossary

PLANETProfessional Landcare Network

plant growth regulatorcompound effective in small quantities that affects the growth and/or development of plants. May be naturally produced (hormone) or synthetic (see plant hormone).

Plant Health Care(PHC) comprehensive program to manage the health. structure. and appearance of plants in the landscape.

Plant Health Care (PHC)comprehensive program to manage the health. structure. and appearance of plants in the landscape.

plant hormonesubstance produced by a plant that. in low concentrations. affects physiological processes such as growth and development. often at a distance from the substance's point of origin (see plant growth regulator).

plantinginstalling a plant in the landscape.

planting pithole dug in the soil to plant a tree or other plant.

planting sitelocation chosen to plant a tree. including its surroundings.

planting specificationsdetailed plans and statement of particular procedures. requirements. tools materials. and standards for planting.

plasmodesmatajunctions through cell walls that connect the cytoplasm of adjacent plant cells. forming a circulatory and_ communication system connecting the cells in plant tissue.

pleachingspecialty technique of pruning and training branches or vines. generally horizontally and where they may be interwoven. often to form an arbor. wall~ or arching tunnel.

plunge cutusing the tip of a chain saw to cut into or through the middle of a piece of wood. Back-cut technique in which the hinge is established by cutting through the stem behind the notch then cutting back away from the hinge. Bore cut.

pole1 in utility systems. vertical structure (often made of wood) used to support utility line above the ground. 2) a long too] handle u ed to work at a distance. In tree care and removal operations. poles are made of non-conductive materials such as wood or fiberglass. Consumer poles are(...)

pole chain sawa small chain saw mounted on a pole and used to cut branches from a distance.

pole prunerlong-handled. scissors-like tool used to make small pruning cuts.

pole sawlong-handled tool with a pruning saw on the end. used to cut branches from a distance.

pollardingspecialty pruning technique in which a tree with a large-maturing form is kept relatively short. Starting on a young tree. internodal cuts are made at a chosen height. resulting in sprouts. Requires regular (usually annual) removal of the sprouts arising from the same cuts. Callus knobs(...)

pore spaceair or water-filled spaces between soil particles.

poroushaving spaces or holes through which liquid or air may pass.

Portawrapbrand name of a device used to create and manage friction in the lowering line (load line) in rigging operations.

positive-locking(obsolete) in reference to carabiners and snaps. locking automatically and requiring two or more motions to prepare the gate to open. Prevents unintentional opening.

postemergence herbicideHerbicide applied or effective during the period after seedling emergence

pot boundsee root bound.

potential energystored energy that an object has due to its position in relation to a fixed. horizontal plane.

powdery mildewany of various fungi of the genus Erysiphe producing powdery conidia that appear as a white. fuzzy coating on the upper leaf surfaces. often causing distortion of the leaf.

powerrate of work done per unit of time.

PPEpersonal protective equipment

predatorany organism that preys on another organism.

preemergence herbicideHerbicide applied or effective during the period before seedling emergence

prescription fertilizationphilosophy of basing fertilization recommendations on plant needs. which are primarily determined by soil or tissue testing.

prescription fertilization (fertilisation)basing fertilization on plant needs as determined by conducting soil and/or foliar nutrient analysis. setting plant health goals. and selecting a fertilizer to achieve the goals.

preventionproactive process intended to guard against an adverse impact by avoiding or reducing the risk of its occurrence.

preventive maintenanceroutine service and upkeep performed to avoid development of future problems. failure or breakdowns.

primary elementsnitrogen (N). phosphorus (P). and potassium (K . lncluded in various ratios in fertilizer (see essential elements. macronutrient. and micronutrient).

primary growthroot and stem growth in length. Occurs at the apical meristems of all vascular plants.

primary injuryInjury that is the principal or fundamental problem

primary (primary line)in an electric utility system. a high-voltage distdbution electric supply line. usually 2.400 to 34.500 volts. that carries electricity from distribution substations to distribution transformers.

Proctor testtest used to determine the relationship between soil moisture content and soil density.

progressive reductiona phased reduction in crown height and/or spread over a period of years or decades.

propagationprocess of increasing plant numbers. both sexually and asexually.

protection zonesee tree protection zone and branch protection zone.

provenancegeographic origin of a plant. differing from the range of a species or where a specie can be expected to be hardy.

proximate causelegal term that describes an act or omission that can be attributed as cause of loss and/ or injury.

pruning sawhand saw designed for pruning trees. generally with a bowed blade and teeth oriented for cutting on the pull stroke.

Prusik looploop of rope used to form a Prusik hitch for climbing or rigging.

Prusik mindingspecific type of pulley configured with extended cheek plates to keep a Prusik hitch from jamming in the sheave.

pubescenceshort. soft hairs covering the surface of leaves or other plant parts.

PUCpublic utility commission

PUDpublic utility district

pull line (tagline)line attached near the top of a tree or tree section to be felled or any tree section being removed to help pull or guide it in the desired direction or to control its swing.