Chapter 11: Plant Health Care Flashcards
(110 cards)
1
Q
pesticides
A
any chemical used to control or kill unwanted pests such as weed, insects, or fungi
2
Q
Plant Health Care
A
PHC; comprehensive program to manage the health, structure, and appearance of plants in the landscape; approach to managing trees that recognizes that tree health problems are often the result of many factors, not just a single agent; holistic approach to make management decisions that focus on plants and their interactions with the living and nonliving elements of the landscape; attempts to prevent problems before they start; proactive and cost-effective approach to manage plant health; involves proper planning, plant selection, and a wide range of cultural practices aimed at improving site and soil conditions; a philosophy, an educational process, and a decision-making process
3
Q
Competition with trees above and below ground
A
above - light
below - water, minerals, and space
4
Q
elements of a landscape includes?
A
soil, shrubs, herbaceous plants, turfgrass, and hardscape; arborists cannot view trees in isolation
5
Q
What kind of different contractors might a property owner hire?
A
tree service for maintenance of trees, lawn care company to manage lawn, and landscape company maintenance firm to care for the other elements of the landscape
6
Q
Where does PHC begin?
A
with the design of the landscape and selection of plants
7
Q
What constitutes a healthy plant?
A
free of disorders and pests and has sufficient ability to resist stress
8
Q
vitality
A
overall health; ability of a plant to deal effectively with stress and thrive in a given environment
9
Q
vigor
A
overall health; capacity to grow and resist stress, sometimes limited in reference to genetic capacity; plant’s inherit genetic capacity to resist stress
10
Q
What define’s a plant’s vigor?
A
tolerance of various soil types, moisture conditions, cold or heat, and other factors
11
Q
How to manage plant vigor?
A
select plants well suited for the environment and resistant to pests
12
Q
resource allocation
A
in plant physiology, distribution and use of photosynthates for various plant functions and processes; in management, distribution of materials or other assets to accomplish objectives
13
Q
What are the four primary functions for photosynthesis?
A
maintenance (including reproduction), growth, storage, and defense
14
Q
What influences energy allocation to each primary function?
A
tree age and health, seasonal and environmental conditions, stress factors, cultural practices, and even by ecological strategies
15
Q
What does photosynthesis require?
A
light, water, CO2, chlorophyll, and a few essential minerals
16
Q
stress factor
A
any condition that limits a plant’s ability to obtain or use these key resources (or that leads to excessive amounts); often directly related to soil quality or other environmental conditions and may be attributed to human activity
17
Q
“survival mode”
A
when a tree is stressed and redirects resources away from growth, storage, and defense, and toward reproduction and maintenance
18
Q
physical defense mechanisms
A
thorns, spikes, tiny hairs on the leaves, or leaves with thick, toughened cuticles
19
Q
cellulose
A
complex carbohydrate found in the cellular walls of the majority of plants and algae and certain fungi
20
Q
lignin
A
organic substance that impregnates certain cell walls to thicken and strengthen the cell to reduce susceptibility to decay and pest damage
21
Q
How do cellulose and lignin serve as a cellular defense mechanism?
A
because many herbivores, and even some pathogens, cannot digest these compounds
22
Q
Is the compartmentalization process an anatomical or chemical defense mechanism?
A
both, because it resists insect damage and disease spread
23
Q
allelochemicals
A
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; compounds that have toxic or deterring effects on certain herbivores
24
Q
tannins
A
organic substance produced by trees; believed to be involved in a tree’s chemical defense process
25
phenols
naturally produced organic alcohol with acidic properties; one of several chemical defense compounds in trees
26
herbivores
an animal that feeds primarily on plants
27
Examples of natural insecticides
nicotine, pyrethrin, neem, and rotenone
28
What effect does moderate drought stress have on allelochemical levels?
can increase the levels of allelochemicals, perhaps boosting a tree's defense system
29
Is a rapidly growing tree always a healthier tree?
No, photosynthates may be diverted from defense compound production to increased growth of succulent tissues; increased growth without a corresponding increase in photosynthetic rate of individual leaves may stress the plant
30
How may a tree react if water is limited?
close stomata, levels of dissolved substances in cells may change to maintain turgor pressure, and the root:shoot ratio may increase; long term moisture stress may trigger more dramatic responses like leaf drop
31
How may a tree react to low light levels?
increase shoot growth toward the light source and adjust leaf size and thickness to maximize photosynthesis
32
How may a tree react to nitrogen deficiency?
decrease shoot growth and increase root growth to maximize mineral uptake and availability for existing foliage; produce smaller and thicker leaves
33
mortality spiral
sequence of stressful events or conditions causing the decline and eventual death of a tree
34
resource allocation in young trees vs. mature trees
young trees can afford to allocate more energy to growth than to defense; defense is more critical than growth to mature trees
35
appropriate response process
ARP; method of systematically assessing plant health and client needs to determine which course of action, if any, is recommended; process of gathering information, assessing the severity and implications of the problem, determining client expectations, formulating options, and deciding on a course of action
36
thresholds
in Integrated Pest Management, pest-population levels requiring action; in hazard assessment, risk assessment, and risk management, levels of risk requiring action
37
Integrated Pest Management
IPM; method of controlling plant pests by combining biological, cultural, mechanical, physical, and/or chemical management strategies; a component of PHC
38
What criteria defines a pest?
1. ) it competes with desirable plants for resources
2. ) it threatens the health, structural integrity, or appearance of desirable plants
3. ) it diminished personal enjoyment, utility, or safety in the landscape
39
focus of PHC with pests
pest prevention and suppression rather than eradication
40
What will an appropriate IPM strategy do?
1. ) avoid harmful effects on beneficial and nontarget organisms (people, animal, beneficial insects, and plants)
2. ) cause minimal disturbence in the built and natural environments
3. ) promote plant health, structural integrity, and appearance
4. ) achieve the goals of the client in a cost effective manner
41
monitoring
keeping a close watch; performing regular checks or inspections; programming of regular landscape inspections to make observations and collect information to aid in making decisions about the management of pests and other disorders
42
What three types of information should be collected during a landscape inspection?
site information, plant information, and disorder information
43
Valuable site information includes?
recent weather trends, landscape management practices, changes in drainage or land contour, addition or removal of nearby plant material, and hardscape construction or repair
44
Valuable plant information includes?
leaf number, size, and color; twig growth; symptomatic reactions; and/or any signs of disorders
45
action threshold
pest population or plant damage level that requires action or prevent irreversible or unacceptable physiological and/or aesthetic harm
46
phenology
relationship between the climate and biological events, such as flowering or leafing out in plants; relationship between recurring biological events and weather changes
47
Types of pest information to be collected during a landscape inspection?
1. ) a description or identification of the pest or disorder
2. ) population level or severity
3. ) life stage(s) present, symptoms, and signs
4. ) the potential for natural control of the pest
48
Tools to aid in on-site landscape inspection and monitoring?
hand lens, binoculars, field guide, soil probe, starch test kit, and sample collection containers
49
Use of trapping devices?
to monitor pest abundance and life stage, to evaluate action thresholds, and to properly time management tactics
50
phenology calendar
method for tracking the seasonal development of pests; pests can be reasonably predicted by observing the budding, leaf expansion, flowering, or fruiting stages of common native or landscape plants
51
degree-day
difference between the daily average temperature and a given temperature base; quantitative method for accounting for the effect of seasonal warming on pest development
52
How to calculate degree days?
the threshold value (50 degrees F) is subtracted from the daily average temperature; the difference equals the degree-day units for that day; negative units are recorded as zero
53
key stressors
pests or site conditions that are frequently encountered in landscapes and predictably cause injury to landscape plants
54
key plants
species that has a high susceptibility or common mismanagement or a specimen that has significant value to the client
55
Key aspects of pest prevention in the landscape?
1. ) minimizing plant stress by improving site conditions
| 2. ) minimizing pest activity by discouraging conditions that favor its development
56
What are some landscape sanitation practices?
removing diseased, dead, and fallen twigs, leaves, and fruit to reduce pest populations
57
monocultures
cultivation or planting of a single species on agricultural land, in a forest setting, or within an urban landscape; extensive plantings of the same species
58
Why are monocultures not ideal?
high density of a vulnerable plant species may favor insect and pathogen spread, species susceptible to environmental conditions such as drought, ice storms, or high winds can be devastating; plant diversity may promote natural pest control by providing alternate food sources and refuge for natural enemies of pests
59
Pest management goals for PHC practitioners?
1. ) prevention
2. ) eradication
3. ) suppression
60
prevention
proactive process intended to guard against adverse impact by avoiding or reducing the risk of its occurrence; sometimes insufficient for managing pest populations and plant injury at tolerable levels
61
eradication
total removal of a species from a particular area; may refer to pathogens, insect pests, or unwanted plants; uncommon goal because it is usually unwarranted and difficult to achieve; considered when dealing with highly noxious, introduced pests
62
suppression
management practices intended to reduce the pest population and associated plant injury to a tolerable level; most common insect pest control goal in PHC; usually can be achieved with limited applications of low-toxicity pesticides or non at all and still meet expectation for landscape appearance and helth
63
Considerations when devising a PHC management strategy?
1. ) communicate with the client to establish management goals and identify the management options for the pest, disease, or disorder
2. ) consider the advantages or disadvantages of each management plan
3. ) whenever possible, choose the management option that has the least detrimental impact on the landscape ecosystem
4. ) keep in mind that a management strategy that integrates complementary tactics is most effective
64
cultural control
method of controlling plant pests by providing a growing environment favorable to the host plant and/or unfavorable to the pest; landscape management practice to promote plant health (thereby reducing pest susceptibility) or suppress pest populations
65
Examples of cultural practices?
augmenting soil pH and organic matter content (promotes plant defense mechanisms), proper mulching (minimizes damage caused by pathogens, stem-feeding rodents and insects, and stem-girdling roots), pruning (suppresses localized pest populations such as canker diseases and crown clearing of dead and declining branches can remove breeding and refuge sites for certain pests), sanitation (remove and dispose properly of dead or infested plant material that accumulates in the tree or on the ground
66
biological control
method of managing plant pests or weeds through the use of natural predators, parasites, or pathogens; suppression of pest population by natural enemies; generally slow and less consistent in managing pests than other controls
67
Types of natural enemies in biological control
predators, parasites, and pathogens
68
predators
any organism that preys on another organism
69
parasites
organism living in or on another living organism (host) from which it derives nourishment to the detriment of the host, sometimes killing the host
70
pathogens
causal agent of disease, usually refers to micoorganisms
71
Approaches to applied biological control
introduction, conservation, and augmentation
72
introduction in biological control
attempts to create natural checks and balances for noxious exotic pests where none previously existed by introducing foreign predators, parasites, and pathogens
73
conservation in biological control
involves strategies to conserve existing predators, parasites, and pathogens, such as providing supplemental habitat and limiting use of broad-spectrum pesticides
74
augmentation
in PHC, the release of beneficial organisms to suppress pest insect or mite populations; rearing and release of beneficial organisms to supplement existing populations in the landscape
75
Examples of beneficial organisms commercially available for use in IPM programs?
lady beetles, lacewings, predatory mites, and parasitic wasps
76
chemical control
control of pests using conventional pesticides
77
Types of pesticides
insecticides, miticides, fungicides, bactericides, repellents, and herbicides
78
insecticide
substance toxic to insects
79
miticide
chemical compound that is toxic to mites
80
fungicide
chemical compound that is toxic to fungi
81
bactericide
pesticide that is used to kill or inhibit bacteria in plants or soil
82
herbicide
chemical compound that kills vegetation
83
contact pesticides
materials that cause pest injury or death on contact; suppress or kill pests through direct physical contact with the material or its residue
84
systemic pesticides
pesticide that moves throughout a tree after it has been injected or absorbed (often by roots or foliage); move within the plant after applied to the foliage, stem, or soil
85
What types of insects do systemic pesticides generally target?
sucking, leaf-mining, or cambium-feeding insects
86
Pros and Cons of contact pesticides
contact generally kills surface pests rapidly, but effectiveness depends on thorough spray coverage and proper timing (challenging with large and dense plants or plants in sensitive landscapes or when rain/wind does not permit application)
87
Pros and Cons of systemic pesticides
systemic takes longer and may require repeated applications for sustained pest control but has less environmental exposure than with spraying; has potential for ground water contamination from soil application depending on soil and site characteristics; may injure plant from stem injections
88
Process when using pesticides
1. ) identify the pest or disorder
2. ) evaluate the potential severity of the pest population
3. ) choose an appropriate pesticide that primarily targets the intended pest
4. ) use the correct dosage
5. ) apply at the recommended time and frequency
6. ) employ the correct application technique
7. ) always adhere to pesticide label instructions and all applicable pesticide regulations
89
What is pesticide selection based on?
pest identification, host plant identification, sensitivity of the environment, client expectations, and government regulations
90
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; pest population rebounds in the absence of natural enemies that are slower to repopulate than the pest
91
secondary pest outbreaks
increase in a secondary pest population following a reduction in the population of natural predators or parasites; a secondary pest takes advantage of the lack of competition and predators to become a prominent pest when the primary pest and natural enemies remain suppressed
92
How to minimize pest resurgence and secondary pest outbreaks?
choose narrow-spectrum pesticides and make precise, targeted pesticide applications based on landscape monitoring
93
pesticide resistance
ability to withstand certain pesticides; survival of just a few genetically resistant pests that reproduce can lead to populations that are resistant; when a pesticide selectively kills members of a pest population leaving only the resistant individuals to pass along their traits to future generations
94
How to reduce pesticide resistance?
use multiple pesticides with different active ingredients or modes of action in a rotation system; avoid treating repeatedly with the same chemical
95
How to avoid injury to nontarget organisms and the environment?
choose the least toxic, most narrow-spectrum pesticide necessary to meet the pest management objective
96
Types of alternative pesticide options?
biorational control products, insecticidal soaps, horticultural oils, botanical pesticides, insect growth regulators, and microbial pesticides
97
biorational control products
control product or pesticide formulated from naturally occurring plant extracts, microbes, or microbial by-products that poses very low risk to nontarget organisms; or control product or pesticide that has limited environmental persistence and poses very low risk to nontarget organisms
98
Types of biorational control products?
insecticidal soaps, horticultural oils, botanicals, insect growth regulators, microbial-based products, and microbial agents
99
Whey are biorational control products less toxic?
have residual activity, are pest specific, have unique modes of action
100
insecticidal soaps
soap-based pesticide approved for application to plants to kill insects and certain mites by disrupting the cell membranes; highly refined soaps that disrupt cell membranes of soft-bodied insects and mites
101
horticultural oils
highly refined petroleum oil that may be applied to plants to smother certain insects and other pests by disrupting their respiration; suffocate certain insects or disrupt their membranes
102
Types of horticultural oil applications
summer oil applications and dormant oil applications; vary based on timing and rates
103
dormant oil treatments
applied before budbreak and are highly effective on some pests without damaging beneficial insects
104
summer oil treatments
sprayed on the foliage of some plants during dry periods
105
phytotoxic
term to describe a compound that is poisonous to plants
106
botanical pesticides
pesticides derived from plants; plant extracts used for insecticidal purposes; range from highly toxic to quite mild for both insects and humans
107
Examples of botanical pesticides?
neem, pyrethrin, rotenone
108
insect growth regulators
substance, mad-made or naturally occurring in insects, that affects growth and development of insects; compounds that act like insect hormones, disrupting the molting or growth process; control populations by disrupting the mating process of certain insects or by making the adults sterile
109
microbial pesticides
pesticides derived from microorganisms; contain insect pathogens or lethal microbial byproducts that are derived from extracts of bacterial pathogens of insects; almost no toxicity to nontarget organisms or the environment
110
mechanical management
picking pests off of a single shrub or installing physical barriers to keep pests away or pruning out infested plant parts
