Final Study Guide Flashcards
(125 cards)
0
Q
Invasive species
A
Non native or alien to the ecosystem or a species whose introduction causes economic, environmental, or human health problems
1
Q
Define weed
A
ANy undesirable plant in an environment that is competitive with desirable plants or has no function.
2
Q
3 ways seeds are dispersed,
A
Wind, water, animals
3
Q
Define ecology
A
The study of organisms in their environment.
4
Q
What is a perfect flower?
A
A flower with all reproductive parts.
5
Q
What does WSSA Stand for?
A
Weed science society of America.
6
Q
Dioecious
A
A plant species that has pistillate and staminate flowers on different plants
7
Q
Leaf arrangement in which there are two leaves per node.
A
Opposite
8
Q
Rhizomes
A
Horizontal underground stems
9
Q
A group of organisms within the same species that occur in a given time and space.
A
Population
10
Q
Glabrous
A
Leaf that is smooth
11
Q
Horizontal above ground stems
A
Stolons
12
Q
Dehiscent
A
Term for type of dry fruit, in which the fruit splits open at maturity
13
Q
A community plus it’s non living environment
A
Ecosystem
14
Q
Leaf arrangement with 3 or more leaves per node
A
Whorled
15
Q
A flower with stamens but no pistil
A
Staminate
16
Q
Anther and filament make this structure
A
Stamen
17
Q
Niche
A
An organisms place in its environment
18
Q
Aggregate
A
A fruit that develops from several ovaries within one flower.
19
Q
An orderly change in species resulting from modification of the physical environment by the plant community
A
Succession
20
Q
Monocots have how many:
Cotyledons in seed?
Number of flower parts?
Leaf venation?
A
One
3s
Parallel
21
Q
Dicots have how many:
Cotyledons per seed?
# of flower parts?
Leaf venation?
A
Two
4s or 5s
Branched
22
Q
Reasons herbicides are the main method of controlling weeds,
A
They are cheaper
More reliable
Higher return on investment
23
Q
Induced dormancy
A
Type of dormancy in which unfavorable conditions cause sees to go dormant.
24
r group
Plants that are short lived and produce lots of seed.
25
The K group
Longer lived less seeds
26
Obligate weeds
Weeds that have never been found in the wild stage and that grow only in association with man.
27
A plant that completes its life cycle in one year
Annual
28
Negative effects of weeds
```
Reduced yields
Increased costs
Hard to remove
Harbor other crop pests
Interfere with harvests
Extra cleaning and processing
```
29
Ideal characteristics of weeds
```
Quickly reproducing
Competitive
Tolerant of stressful conditions
Hard to get rid of
Produces lots of seeds
Quickly germinating
```
30
What are the goals of herbicide application?
To kill or suppress the grown of plants
31
Define formulation
Preparation supplied by manufacturing for use,
| Manufacturing process carried out by the formulator in preparing a chemical for packaging,
32
Dry formulation types
Water soluble powders and water dispensable granules
33
Liquid formulation types
Water soluble liquids and water dispersal liquids
34
Dry formulation for direct application
Granules and pellets
35
What carries can be used for herbicide applicators
Water or other liquids
36
Adjuvant define
Any substance in herbicide formulation or added to spray tank to modify herbicidal activity
37
What does a Wetting agent do?
Enables spray deposit to spread and make better contact with plant surface
38
What are the 5 types of adjuvants
```
Surfactants
Crop oil concentrate
Comparability agents
Anti foaming agents
Drift control agents
```
39
What is the range for ground applications?
10 - 20 GPA
40
What is the range for Air spraying
3- 10 GPA
41
why do different nozzle sizes matter
Poor control
Crop injury
Wasted chemical
42
How should herbicides be stored
In a locked temperature controlled area with chemical resistant container treys
43
How do you dispose of herbicides
Triple rinse, drain, and puncture
44
What are the 3 types of herbicide names
Common, chemical, trade name
45
What's the difference in selective herbicides and non selective
Selective are more toxic to some plants than others
| Non selective toxic to all plants
46
Short residual herbicides
Injure or kill in short periods and used in rotated crops
47
Long residual herbicides
Soil sterilants, herbicides used in non-crop perennial crops.
48
Non-residual herbicides
No soil activity noticeable, burn down herbicides and selective post herbicides.
49
Use to kill crops before planting
Preplant burndown
50
Herbicide rolled into the soil before planting
Preplant incorporated
51
Application of herbicide at time of planting or before crop emergence
Preemergence
52
After crop or weed emergence
Post emergence
53
Difference between systemic and contact herbicides?
Systemic translocation to phloem
| Contact -no movement plant tissue damaged after exposure
54
Symplastic transport site in plant
Phloem affects photosynthesis
55
Apoplastic transport location
Xylem moves up only
56
What types of properties or characteristics are used to group herbicides into families
Physical/ chemical, biological, environmental fate and impact, toxicological hazards.
57
Measure of the amount of compound that is harmful or lethal when exposed by ingestion, inhalation, or dermal exposure.
Toxicity
58
Probability of encountering a harmful dose of a compound.
Exposure
59
What does oncogenicity mean?
Tumor producing
60
The six Carcinogenicity
Six cancer potential categories
61
Birth deformities
Tetratogenicity
62
Genetic abnormality
Mutagenicity
63
What is the difference between acute and chronic toxicity?
Acute is harm after short exposure and chronic is repeat exposure.
64
What is mode of action?
The plant process affected by the herbicide.
65
What is mechanism of action?
The biochemical site within a plant each herbicide directly interacts with.
66
3 herbicide classification systems
WSSA , AUstrailian, Herbicide resistance action committee
67
Lipid synthesis inhibitors are in what group?
WSSA 1 and blocks production of phospholipids
68
Amino acid synthesis inhibitors group?
WSSA 2 reduction of cell division
69
Nitrogen metabolism inhibitors group?
WSSA 10 increase in ammonia.
70
Growth regulators group
WSSA 4 clogs xylem and phloem
71
Mitosis inhibitors group
WSSA 15 microtubules inhibitors
72
What does LD 50 mean
Dose of a substance lethal to 50% of organisms
73
What does LC50 stand for?
Concentration of a substance lethal to 50% of organisms
74
What are the five types of toxicological studies that must be done on herbicides?
Acute, subacute, chronic feeding and oncogenicity, fish and aquatic organisms, birds
75
How long does it take to develop and register a new herbicide?
10-12 years
76
Difference between general use pesticide and restricted use?
General use - no reasonable adverse effects on environment and safe to apply
Restricted use- sold only to trained and certified applicators.
77
Section 18 allows for?
Emergency situation application
78
IR -4 allows for
Research project anoung state exp stations
79
DANGER
Highly toxic
80
Warning
Moderately toxic
81
caution
Slightly toxic
82
Preventative measures when spraying?
Long sleeves and pants, gloves, shoes and socks , eyewear.
83
What is included on a herbicide label?
Mixing instructions, spraying instructions, calibration, application directions.
84
What informating needed when identifying problems with herbicide?
Locate crop injury, access crop condition, determine if label was followed , record all important information.
85
What factors other than herbicide application can cause a problem?
Application at wrong stage of growth
86
What is carrying capacity
The plant density that can be maintained in a given community over time.
87
What 5 morphological factors of weeds are important?
```
High germination rate
Early extensive root system
Large expansive foliage
Multiple shoots
Climbing growth
```
88
What is the LAI? Leaf area index?
Amount of photosynthetic material or leaf suspended per unit of area of land.
89
When does a weed become competitive in LAI?
At 1.0
90
How do weeds reach the LAI ?
Through size density,
91
The interaction among species involving both competition and allelopathy,
Interference
92
The inhibition of one plant by another through release of toxins,
Allelopathy
93
The mutually adverse effects of plants which are competing for a resource in short supply.
Competition
94
Interference of plants of the same species.
Intraspecific interference
95
Interference of plants of a different species
Interspecific interference
96
What weed factors are important?
```
Species cultivar,
planting date,
planting rate,
duration,
Growth rate growth habit
Allelopathy
```
97
What crop factors are important?
```
Species cultivar
Planting date
Planting rate
Duration
Growth rate
Allelopathy
```
98
Other factors that influence interference?
```
Weather
Soil type
Soil fertility
Tillage
Herbicides and pests
```
99
Sigmoid relationship chart axis
Y:
X:
Y: crop yield
X: weed density
100
What does a longer critical period mean?
The crop is less competitive
101
How can weeds still have an effect of there is no yield loss from competition?
It can still produce seeds
102
6 general method of control
```
Preventative and regulatory
Mechanical
Cultural
Biological
Herbicide
Biotechnical
```
103
What is preventative control?
The prevention of introduction, establishment, and spread of specific weeds.
104
Farm management practices can be taken to reduce weeds in weed sanitation?
Plant weed free seed, clean equipment, screen irrigation water, inspection, pay special attention
105
What regulations are in place for weed seed in seeds?
There are noxious laws that prevent noxious weed seed in planting sees or nursery stock.
106
What are noxious weeds?
Weeds that cannot be sold and are limited by number / lbs
107
Isolates or prevents the spread of?
Quarantine
108
Elimination of weed species?
Eradication
109
Implies a reduction in an infestation level?
Control
110
What are the mechanical methods of weed control?
Tillage, hand picking, mowing, smothering or mulching.
111
Advantages and disadvantages of mechanical control
Adv: selective, effective, alternative to herbs, stimulates germination, destroys.
Dis: time consuming, tedious, expensive,
112
Primary tillage is how deep?
| Secondary tillage?
P: 6- 36
Sec: less than 6
113
Disadvantages of mechanical tillage
Soil erosion, energy requirements, increases weed, damages crops, buries weed seed.
114
Use of clear plastic film to cover soil for disease and insect control
Solarization
115
3 areas hand weeding is still used?
Homeowners,
High priced horticulture
Organic farmers
116
What weed can survive flooding?
Johnsongrass
117
What types of management practices improve crop competitiveness?
Optimum planting date
Seeding rate
Fertility and irrigation
Cultivar selection
118
What is biological weed control?
Using natural methods to fight weeds,
| Ex. Bugs
119
Why are biological controls usually aimed at perennial weeds?
2/3s of them are perennial!
120
Types of biological control? 3
Classical- natural predators
Mycroherbicidal- fungal spores
Feeding- animals
121
What are the 8 contributions of herbicides?
```
Cost effective
Permit control
Reduce tillage
Reduce human effort
Controls difficult weeds economically
Flexible management system
Can solve most weed problems
```
122
Major risks of using herbicides?
Drift injury
Persistent in soil residues
Inconsistent weed control
Resistant weeds
123
What is integrated weed management?
The integration of environmentally safe sociologically acceptable control tactics, that reduce weed interference below the economic injury level
124
What are benefits of integrated weed management?
```
Wholesome food
Increased outputs
Economic stability
Increased biodiversity
Increased productivity
```
