Chapter 11: Plant Health Care

Allelochemical
substance produced naturally by plants as part of a defense against pests and other plants. May adversely affect the growth and development of other plants.
Appropriate response process (ARP)
method of systematically assessing plant health and client needs to determine which course of action, if any, is recommended.
Botanical pesticide
pesticides derived from plants.
Cellulose
complex carbohydrate found in the cellular walls of the majority of plants, algae, and certain fungi
Contact pesticide
materials that cause pest injury or death on contact.
Cultural controls
method of controlling plant pest by providing a growing environment favorable to the host plant and/or unfavorable to the pest
Fungicides
chemical compounds that are toxic to fungi
Horticultural oils
highly refined petroleum oil that may be applied to plants to smother certain insects and other pests by disrupting their respiration.
Insect growth regulators
substance, man-made or naturally occurring in insects, that affect growth and development of insects.
Insecticidal soaps
soap-based pesticide approved for application to plants to kill insects and certain mites by disrupting the cell membranes.
Insecticide
substance toxic to insects
Integrated Pest Management (IPM)
method of controlling plant pest by combining biological, cultural, mechanical, physical, and/or chemical management strategies.
Lignin
organic substance that impregnates certain cell walls to thicken and strengthen the cell to reduce susceptibility to decay and pest damage.
Microbial pesticide
pesticide derived from microorganisms.
Monitoring
keeping a close watch; performing regular checks or inspections
Mortality spiral
sequence of stressful events or conditions causing the decline, and eventual death, of a tree
Pest resurgence
increase in the population of a pest following a reduction in the population of natural predators or parasites of that pest. Usually the result of a nonspecific pesticide or unfavorable environmental condition.
Pesticide
chemicals used to control or kill unwanted pests such as weeds, insects, or fungi.
Phenol
naturally produced organic alcohols with acidic properties; one of several chemical defense compounds in trees.
Plant Health Care (PHC)
comprehensive program to manage the health, structure, and appearance of plants in the landscape
Resource allocation
(1) in plant physiology, distribution and use of photosynthates for various plant functions and processes. (2) in management, distribution of materials or other assets to accomplish objectives.
Secondary pest outbreak
increase in a secondary pest population following a reduction in the population of natural predators or parasites
Systemic pesticide
pesticide that moves throughout a tree after it has been injected or absorbed (often by roots or foliage).
Tannin
organic substance produced by trees; believed to be involved in the tree’s chemical defense process.
Threshold
(1) in Integrated Pest Management, pest populations levels requiring action. (2) in hazard assessment, and risk management, levels of risk requiring action.
Vigor
overall health; capacity to grow and resist stress. Sometimes limited in reference to genetic capacity.
Vitality
overall health; a plant’s ability to deal effectively with stress.
action threshold
pest population or plant damage level that requires action to prevent irreversible or unacceptable physiological and/or aesthetic harm.
augmentation
in Plant Health Care, the release of beneficial organisms to suppress pest insect or mite populations.
bactericide
pesticide that is used to kill or inhibit bacteria in plants or soil.
biological control
method of managing plant pests or weeds through the use of natural predators, parasites, or pathogens.
biorational control product
(1) control product or pesticide formulated from naturally occurring plant extracts, microbes, or microbial by-products that poses very low risk to nontarget organisms. (2) control product or pesticide that has limited environmental persistence and poses very low risk to nontarget organisms.
chemical control
control of pests using conventional pesticides.
contact pesticide
degree day
difference between the daily average temperature and a given temperature base.
eradication
total removal of a species from a particular area. May refer to pathogens, insect pests, or unwanted plants.
herbicide
chemical compound that kills vegetation.
herbivore
an animal that feeds primarily on plants.
miticide
chemical compound that is toxic to mites.
monoculture
cultivation or planting of a single species on agricultural land, in a forest setting, or within an urban landscape.
parasite
organism living in or on another living organism ( host) from which it derives nourishment to detriment of the host, sometimes killing the host.
pathogen
causal agent of disease. Usually refers to microorganisms.
pesticide resistance
ability to withstand certain pesticides; survival of just a few genetically resistant pests that reproduce can lead to populations that are resistant.
phenology
relationship between the climate and biological events, such as flowering or leafing out in plants.
phytotoxic
term to describe a compound that is poisonous to plants.
predator
any organism that preys on another organism.
prevention
proactive process intended to guard against adverse impact by avoiding or reducing the risk of its occurrence.
repellent
a substance that deters insects or other pests from approaching or settling.
suppression
management practices intended to reduce the pest population and associated plant injury to a tolerable level.