Weed Science Lab Midterm 2023

What are all the parts of a grass?

Blade

part of the leaf that doesnt surround the stem

Sheath

portion of the leaf that surrounds stem

Node

joint of stem, point of leaf attachment

Collar

leaf attachment to stem (key to ID grasses)

Ligule

thin projection at the base of sheath

Auricle

appendages at the opening of sheath

What are the two specialized stems for grasses?

Rhizomes: below-ground specialized stems (Johnsongrass)

Stolon: above-ground specialized stems (Bermudagrass)

Types of Ligules: Membranous

Types of Ligules: Fringe of hairs

Types of Ligules: Truncate

Types of Ligules: Absent

Types of Ligules: Rounded

Types of Ligules: Tapered

Types of Ligules: Scalloped or toothed

What are the 4 types of auricles?

What are the 3 types of sheaths?

What are the vernation (arrangement of leaf buds) in grasses?

What are the 3 types of stems in grasses?

What are the 3 types of seedheads?

Identifying Dicots: Leaf Parts

Identifying Dicots: What are the 3 types of leaf arrangement?

Identifying Dicots: Types of Leaves - Palmately trifoliolate (ternate)

Identifying Dicots: Types of Leaves - Pinnately trifoliolate

Identifying Dicots: Types of Leaves - Biternate

Identifying Dicots: Types of Leaves - Odd-Pinnate

Identifying Dicots: Types of Leaves - Even-Pinnate

Identifying Dicots: Types of Leaves - Bipinnate

Identifying Dicots: Types of Leaves - Tripinnate

Stipules

Lateral appendages at the base of a leaf (

Examples: Spurred anoda, Prickly sida

Ocrea

Polygonaceae family; a papery sheath that encloses the stem at the nodes, a fusion of 2 stipules

Examples: Pennsylvania smartweed, Ladysthumb

How can the midvein be arranged?

Middle or Offset

Pubescence

presence of hairs (trichomes)

Where can pubescence be found?

All over

Underside of leaf

Around collar region

Seedling only

What is a label?

The information printed on or attached to a pesticide container

What does the label provide the user?

What the product is

What it controls

How it is used

Various precautions

How to mix properly

What it can be used on

Application rate

Where can you find labels?

On the container

www.cdms.net

Manufacturer’s websites

Who regulates pesticides?

EPA under the authority of the Federal Insecticide, Fungicide, Rodenticide Act of 1947

Food Quality Protection Act (more recent)

Worker Protection Standards (more recent)

State government

What is the difference between a label and labeling?

Label: the information printed on or attached to the pesticide container

Labeling: includes the label, plus all other info you receive from the manufacturer about the product

What is a section 3 label?

the regular federally approved label

What does the label mean to different groups?

Manufacturer: “license to sell”

Regulatory groups: a way to control distribution, storage, sale, use, and disposal

User: provides info. on how to use the product, correctly and safely

Physician: a source of info. on the proper treatment for poisoning cases

What is a section 24(c) label?

Special Local Need (SLN): FIFRA specifies a state may provide registration for additional uses of federally registered pesticides to meet a special local need.

What is a section 18 label?

An “emergency condition” that allows someone to use an unregistered pesticide

section 2(ee)

allows a pesticide to be sprayed in conditions not specified on the label

What is the product name of a pesticide?

The trade name (Round-up)

What does the active ingredient include?

Chemical name, CAS #, and concentration

What does the inert ingredients include?

Concentration but not identified

What does KOOROC mean?

Keep out of reach of children (on all lables)

What are the 3 signal words on a label?

Danger: must include poison with a skull and crossbones symbol, Category 1

Warning: moderately toxic, Category 2

Caution: low toxicity, Category 3 and 4

What does PPE mean?

Personal Protection Equipment

What is the purpose of tank mixing two or more pesticides?

Broaden spectrum of control

Save trips across fields

Where can you find the information on what chemicals can be mixed?

any mixtures listed on one or more labels of products under consideration can be mixed

Is it legal to mix two pesticides if neither tank mix partner specifically mentions that mix?

Yes, as long as neither label prohibits that mixture and application rate and timing is within specifications on labels of individual products.

What is SDS?

Safety Data Sheet: provides both workers and emergency personnel with proper safety procedures for handling or working with a particular substance.

What is an Adjuvant?

Any substance in a herbicide formulation or added to the spray tank to modify herbicidal activity or application characteristics

What is the difference between spray and formulation adjuvants?

Formulation: present in the container when purchased by the user; added by the manufacturer for better mixing, handling, shelf-life, formulation stability, efficacy, and drift reduction.

Spray: added to the tank by the user, primarily to improve pesticide performance but also to aid in mixing, reduce drift, and reduce foaming.

What is the difference between activator and utility/spray modifier adjuvants?

Activator: enhance the biological efficacy of the pesticide

Utility/Spray modifier: modify the physical characteristics of the spray mixture.

What is a Surfactant?

WSSA: a material that improves the emulsifying, dispersing, spreading, wetting, or other properties of a liquid by modifying its surface characteristics

ASTM: a material that when added to a liquid medium modifies the properties of the medium at a surface level

How does a surfactant work?

Has a hydrophilic head and lipophilic tail that when mixed reduces the surface tension between the leaf surface and spray droplets and increases the surface area of the droplet across the leaf.

What is crop oil?

A derivative of paraffin-based petroleum oil aka phytobland oil. Consists of oil plus 1-2% surfactant to aid in mixing with water. No longer used in herbicide application.

Are ammonium sulfate (AMS) and urea-ammonium nitrate (UAN) used as adjuvants?

Yes, ammonium ions are thought to be responsible for beneficial effect of herbicide performance.

What do water conditioners and fertilizer adjuvants have in common?

what is a compatibility agent?

a surface-active material that allows simultaneous application of liquid fertilizer and an agrichemical as a uniform tank mix. Basically helps mix two things that otherwise may not mix well.

How do you conduct a compatibility test?

Take 2 jars, put carrier (water or fluid fertilizer) and pesticide in both. If they don’t mix well add a compatibility agent to one of the jars to see if it mixes well. If so tank mix can be used if the compatibility agent is included.

What is a defoaming agent?

a material that eliminates or suppresses foam in the spray tank that occurs from adjuvants in the formulation and agitation of the spray solution.

What is a drift reduction agent?

a material used in a liquid spray mixtures to reduce spray drift

Does a drift reduction agent reduce vapor drift?

No, it only reduces spray drift by increasing the viscosity of the spray solution and increasing droplet size.

What is the difference between spray drift and vapor drift?

Spray: movement of spray droplets off the target site, primarily movement of fine droplets by wind, across a relatively short distance.

Vapor: movement of pesticide off-target site in gaseous form, primarily related to the vapor pressure of herbicide and environmental conditions, can be long distance.

What is the basic purpose of an acidifying and buffering agent?

Acidifying: a material added to spray mixtures to lower pH but will rise if alkaline-based products are added

Buffering: compound or mixture that causes the solution to resist a change in pH, with a characteristic limited range of pH over which it is effective.

Where can you find information on adjuvants?

www.herbicide-adjuvants.com

What is the difference between an adjuvant and a herbicide based on government regulation?

Adjuvants are non-pesticidal and EPA doesn’t regulate

Herbicides are heavily regulated by the EPA and State governments

What is a formulation and what is its purpose?

It is the pesticidal preparation sold by the manufacturer

formulating allows AI to be mixed with a carrier. Aids in mixing with other pesticides and is used to dilute AI due to safety issues. Enhances efficacy

What are the basic types of formulations?

Sprayable formulations

Dry formulations for direct application

Sprayable formulations: Water-soluble liquids, soluble, water-soluble concentrates, or liquid formulation

S, SC, SL, WSC

for water-soluble AI

form true solutions when added to water. Components can’t be separated by physical means, no agitation is required after initial mixing. Transparent but may be colored.

Non-abrasive to nozzles and pumps

Sprayable formulations: Water-soluble powders

SP or WSP

Same as water-soluble sprays but has an inhalation hazard

Sprayable formulations: Emulsifiable concentrates

E or EC

herbicide mixed in with some organic solvent that is soluble, plus an emulsifier to make the formulation with water.

Sprayable formulations: Wettable powders

W or WP

AI combined with finely ground clay carrier and suspension agents

form a suspension (a mixture of finely ground particles dispersed in a liquid) when mixed with water and can be physically separated from liquid

Requires continuous and vigorous agitation

recommended to slurry before adding to the tank

very abrasive

Sprayable formulations: Liquid flowables

F or L

very finely ground solid containing AI suspended in a liquid.

Form suspension in water

Sprayable formulations: Water dispersible granules

DG, WDG, or DF

Basically an WP formulation that has been formed into small granules

Easy pouring and no dust

very abrasive

same agitation as F formulation

Sprayable formulation: Microencapsulated formulations

ME

pesticide particles surrounded by a polymer coating

Dry formulations for direct application: Granules

G

AI impregnated on small dry carrier particles like clay

granule size usually < 10 mm cubed

applied dry with no dilution

rarely used in Ag. crops, common in turf and ornamentals

relatively low % of AI

Dry formulations for direct application: Pellets

P

AI impregnated on dry carrier

Granule size >10 mm cubed

What is a carrier?

the material to which the user adds to the herbicide for application

purpose is dilute the AI to aid in distributing a small amount of AI over a large area

Which form of carrier has the lowest concentrations of AI per unit carrier?

What is the order for mixing tanks?

Follow label directions if given

If no specific label directions

WF → DF → F → EC → SP or SC

Put B for Broadleaf ID, G for Grasses ID, or both

1. Ligule

2. Ocrea

3. Stipule

4. Pubescence

5. Leaf shape

6. Sheath

7. Pinnate leaves

8. Collar

9. Auricle

10. Lobes

1. G

2. B

3. B

4. Both

5. Both

6. G

7. B

8. G

9. G

10. B

Give an example of alternate leaf arrangement;

opposite;

whorled;

odd-pinnate;

even-pinnate;

common ragweed

spotted spurge

carpetweed

poison sumac

hemp sesbania

Name a plant with rhizomes;

stolons;

stipules;

ocrea;

Johnsongrass;

Bermuda grass (has both rhizome and stolon)

Cannabis

Lady’s Thumb

Name 3 types of activator adjuvants

surfactant

crop oil

ammonium fertilizers

name 3 utility/spray adjuvants

defoaming agent

compatibility agent

drift reduction agent

What is the calculation for GPM

(GPA)(MPH)(W)

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(5940)

Calculation for Speed (MPH)

Distance (ft) * 60

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Time (sec) * 88

Calculation for Ounces Per Minute (OPM)

= GPM * 128

For broadcasting how do you find (W)?

For banding?

For Directed crop foliar spray?

nozzle spacing on boom

Band width (in inches)

---

# of nozzles per band

Row spacing (in inches)

---

# of nozzels per row

Formula Calibration Method

1. Select GPA from label

2. Calculate ground speed by traveling 200 ft (3x average)

3. Find GPM of each nozzle

4. select nozzle that delivers that GPM

5. Convert GPM to OPM

6. Collect water output from each nozzle in oz, repeat, find the average for each and replace if > 10% above or below

7. Make adjustments for desired output (Change in pressure = small adjustments)(Change speed or nozzle for large adjustments)

What are the functions of a nozzle?

1. regulate flow

2. form droplets

3. disperse droplets in specific pattern

Factors that affect nozzle flow rate?

1. orifice size

2. pressure (more pressure = higher flow rate)

3. specific gravity of spray solution

4. viscosity of spray solution

Effects of pressure on nozzle output calculation

GPM₁ = Sq root PSI₁

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GPM₂ = Sq root PSI₂

Effect of pressure on sprayer output

GPA₁ = Sq root PSI₁

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GPA₂ = Sq root PSI₂

Effects of Travel Speed Formula (no effect on nozzle output, effects sprayer output GPA)

GPA₁ = MPH ₂

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GPA₂ = MPH₁