weedscience

76問 • 1年前

Anne Ranay

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問題一覧

Who among the following is known as the Father of Weed Science?

Tull

What invention started the recognition of Weed Science?

Hoe

This herbicide was discovered during the World War II and marked the beginning of the herbicide phase of “Chemical Agriculture”.

2,4-D

Author of the first reference textbook in Weed Science, “Introduction to Weed Science”, in the Philippines.

Mercado

Known as the Father of Allelopathy.

Molisch

Damage caused by weeds is generally not visible or noticeable because

weeds seldom cause total crop failure

Which of the following does not characterize weeds?

Limited environmental plasticity

Which of the following describes the negative impacts of weeds?

Both A and B

Which of the following herbicides is allegedly responsible for soil erosion in the provinces in Northern Luzon, resulting to the proposed ban of the product?

Glyphosate

Consider a tomato growing in an onion garden. If the tomato was considered a weed, which of the following definitions of weed fits this scenario?

Out of place

Some weed species can enter reproductive stage as early as three weeks of age.

True

Weed seed dormancy is a survival mechanism to escape favorable environment.

False

Rosette formation is a characteristic that increases the competitive ability of some weed species.

True

All weeds have allelopathic potential, but not all allelopathic plants are weeds.

False

Which of the following negative impacts of weeds is the most important in agriculture?

Decreases crop yield

Weeds that grow and complete their life cycle under dry or wet condition of the soil.

Upland

Lowland weeds with their roots attached to the soil but the shoots are aerial or above water.

Emerged

Weeds that belong to the Family Cyperaceae.

Sedges

Which of the following weeds is considered as a true parasite?

Cuscuta sp.

Which of the following is an example of a broadleaf weed?

Cleome rutidosperma

Which of the following is an example of a grass weed?

Digitaria setigera

Which among the following weed species reproduces by seed alone?

Synedrella nodiflora

The following are classification of weeds based on gross morphology except

epiphytic

Purple nutsedge is characterized by which of the following?

Presence of tuber

Most weeds in the soil are found within the

upper 15 inches

The following are physical causes of weed seed dormancy except

presence of inhibitors

The mechanism which controls sprouting of Cyperus rotundus tubers that are still attached to the mother plant.

Apical dominance

Which among the following is not a weed dispersal unit?

Leaves

The following are means by which weed seeds are dispersed from one area to another, except

Fire

Which of the following weed species is the easiest to spread by wind?

Tridax procumbens

The following are steps in the germination process except

Inhibition

The underground vegetative propagule that can be used for weed propagation.

Tuber

Asexual reproduction of weeds is greatly affected by the following factors except

Minerals

An example of weed dispersal agent

Animal

Described as the struggle between two or more plants for a limited resource.

Competition

The term that collectively describes the effects of both competition and allelopathy.

Interference

The point during the life cycle of a crop when it is most affected with the competition by weeds.

Critical period of competition

The weed density, which beyond that level will cause significant yield losses.

Critical threshold level

The weed density and duration when the crop is most affected.

Crop-weed competitive threshold

Allelopathic substances include the following except

Auxin

The critical period of competition is usually _________ of the life cycle of the crop.

One-third

What type of competition is present between weedy rice and cultivated rice?

Intraspecific competition

It refers to the total adverse effect that plants exert on each other when growing in a common ecosystem.

Interference

Which of the following factors does not affect the degree of competition?

None of the above

What type of allelopathy is it when released substance is toxic in the form in which they are produced in the plant?

True allelopathy

Which of the following is not a cause of interference?

All of the above

What kind of interference is it when plants compete for limited resources?

Negative

What type of competition is given more importance in Weed Science given its economic impact in agriculture?

Interspecific

Which of the following resources do crops and weeds compete for?

All of the above

The process of decreasing weed population to minimize competition.

Weed control

The stage of growth when the weed is most affected by weed control measures.

Seedling stage

Chemicals that are used to kill weeds are called

Herbicides

The world’s worst weeds based on distribution

Cyperus rotundus

These genera of weeds resemble rice at its seedling stage

Echinochloa

Nutrient management is what type of control method?

Cultural method

It is a type of herbicide applied before the crop emerge.

Preplant

What type of herbicide is FLUAZIFOP-BUTYL based on timing of application?

Post-emergence

What type of herbicide is MCPA based on timing of application?

Post-emergence

What type of herbicide is GLUFOSINATE-AMMONIUM based on timing of application?

Preplant

Which of the following herbicides is soil-applied?

Pretilachlor

Which of the following herbicides is non-systemic?

Glufosinate

Which of the following herbicides is Leptochloa chinensis resistant to?

Bispyribac-sodium

It refers to the inherited ability of a plant to survive and reproduce following exposure to a dose of herbicide normally lethal to the wild type.

Herbicide resistance

It is a type of resistance where a weed population becomes resistant to two or more herbicides under the same mode of action.

Cross resistance

Which part of the knapsack sprayer system develops the pressure which forces the liquid materials out of the tank?

Hand lever

Which type of sprayer is most commonly used in plantation farms?

Tractor-mounted sprayer

It refers to the cross-section of the main body of sprayed fluid as it disperses.

Spray pattern

What type of nozzle and spray pattern is appropriate for herbicide application?

Fan type, flat pattern

What is the purpose of sufficient overlap of the spray swath when using boom sprayer?

To optimize weed control

A solid pesticide formulation applied undiluted where the active ingredient is combined with inert ingredients such as clay to form particles about the size of coarse sugar?

Granule

What kind of herbicide is ATRAZINE based on timing of application

pre-emergent

What type of competition is present between weedy rice and cultivated rice?

intraspecific competition

What kind of herbicide is PETILACHLOR based on timing of application?

pre-emergent

What kind of herbicide is 2,4D AMINE OR ESTEE based on timing of application?

post-emergent

What kind of herbicide is GLYPHOSATE based on timing of application?

pre-plant

What type of nozzle type and spray pattern is appropriate for herbicide application?

fan type, flat pattern

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