Tag: cropping patterns

Questions Related to cropping patterns

American water plant that has become a troublesome water weed in India is

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Cyperus rotundus

  2. Eichhornia crassipes

  3. Trapa latifolia

  4. Trapa bispinosa

Show answer
Correct Option: B
Explanation:

Eichhornia crassipes , commonly known as water hyacinth , is an aquatic plant native to Amazon basin, known for it's highly problematic invasion outside it's native range. It forms dense mats in the water bodies, which causes the reduction in the oxygen for other organisms in the water body .

So the correct answer is 'Eichhornia crassipes'

Given below are statements about the harmful effects of weeds on crop plants.
(i) They interfere while harvesting.
(ii) They help crop plants grow healthily.
(iii) They compete with crop plants for water, nutrients, space, and light.
(iv) They affect plant growth.
Choose the correct statements from above.

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. (i), (iii) and (iv)

  2. (iii) only

  3. (iii) and (iv)

  4. (i), (ii), (iii) and (iv)

Show answer
Correct Option: A
Explanation:
Harmful effects of weeds on crop of plant are as follows:
  • They interfere in harvesting.
  • They compete with crop plants for water, nutrients, space and light.
  • They affect plant growth.
  • Presence of weeds increases the cost of agriculture and hinders the progress of work.
  • It increases the irrigation requirement.
  • They reduce the value of produce or otherwise adds the cost of cleaning.
  • Some weeds when eaten (Cleome viscosa) by milch animals will produce an undesirable odour in the milk. At times death/disorder/deformity may occur.  For example, Datura stramonium.
  • The fruits and seeds of Xanthium strumarium and Achyranthes aspera entangle with wool which fetch lower prices.
  • They harbour insect pests, pathogens and parasites.
  • They reduce the value of the land.
  • Presence of weeds will impair the purity of varieties by chance of cross pollination.
  • Weeds cause health hazards to man and animals.
  • Weeds cause allelopathic effect.
Therefore, the correct answer is option A.

Which of the following is a weed?

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Oryza sativa

  2. Cyperinus rotundus

  3. Arachis hypogea

  4. Triticum vulgare

Show answer
Correct Option: B
Explanation:

Weeds can be defined as the unwanted plants that are grown in the field and harm the desired crops. Cyperinus is the most invasive weed found throughout the world. It is the weed of rice field. This is the weed which is commonly found in the temperate regions. 

The prodigious spread of prickly pear (Opuntia) in South India was controlled by

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. cochineal insect

  2. colchicine

  3. DDT

  4. 2, 4-D

Show answer
Correct Option: A
Explanation:

When the invasive species prickly pear was introduced it possessed a threat to the native species. The growth Opuntia is then controlled by the introduction of the species of the cochineal insect.

This was the biological methods of the plant management.
So, the correct option is 'cochineal insect'

'Aquatic' weeds can be utilized and converted into

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Ethanol

  2. Fertilizers

  3. Leather

  4. Solid waste

Show answer
Correct Option: B

Which of the following groups of herbicides is derived from urea, and is used for controlling weeds in tea, tobacco and cotton?

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Carbamates

  2. Triazines

  3. Pyrethroids

  4. Organophosphate

Show answer
Correct Option: B
Explanation:

A carbamate is an organic compound which is derived from carbamic acid (NH$ _{2}$COOH). 

A pyrethroid is an organic compound similar to the natural pyrethrins produced by the flowers of pyrethrums (Chrysanthemum cinerariaefolium and C. coccineum). Pyrethroids now constitute the majority of commercial household insecticides. 
An organophosphate or phosphate ester is the general name for esters of phosphoric acid. 
Triazines show antimalarial, antibacterial, and antimicrobial activities. They are derived from urea and used in tea, cotton and tobacco plantation and some orchid plantation. Thus, option B is correct.

Weeds affect the crop plants by

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Killing the crop plants before they grow

  2. Secreting poisons which cause diseases in crop plants

  3. Competing for various resources of crop plants causing low availability of nutrients

  4. None of the above

Show answer
Correct Option: C
Explanation:

Weeds are unwanted plants in the cultivated field. They compete with the crop plants for food, space and light. They take up the nutrients and reduce the growth of the  crop.

The most important weed against which eradication measures would be taken on war footings is

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Eichhornia

  2. Dactylis

  3. Parthenium

  4. Ageratum

Show answer
Correct Option: C
Explanation:

Parthenium is most common weed which grows anywhere on the land like roadsides, war footings etc.  It releases chemicals to supress the growth of plants and allergents toxic to other livestock. Thus it is important to supress  this weed first. Thus the correct answer is 'Parthenium'. 

The common weedicide used in cultivating fields is 

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. 2, 4 - D

  2. 2,4,5 - T

  3. IAA

  4. ABA

Show answer
Correct Option: A
Explanation:
Weedicides can be defined as the pesticides used to kill the weeds. Bio-weedicides are called herbicides. Herbicide also commonly known as weedkillers, are pesticides used to kill unwanted plants. 2,4-D (2,4-dichlorophenoxy) is a systemic phenoxy herbicide developed in the 1940s and still in use today. The low cost of 2,4-D has led to continued usage, and it remains one of the most commonly used herbicides in the world. 

An American plant, which had become a troublesome waterweed in India is

evs whose forests? improved methods of agriculture cropping patterns food for all conservation of forest and wildlife wildlife deforestation and conservation

  1. Typha latifolia

  2. Trapa bispinosa

  3. Cyperus rotundus

  4. Eichhornia crassipes

Show answer
Correct Option: D
Explanation:

Eichhornia crassipes also known with the common name of water hyacinth is a free-floating aquatic plant native to America. It is often considered a highly problematic invasive species outside its native range. E. crassipes reproduces both vegetatively and sexually, but the vegetative reproduction is responsible for the plant’s rapid spread and colonization of water bodies. It occurs through the formation of stolons, which produce daughter plants. This is generally very rapid, if the temperature is high and nutrients are available, it often invades bodies of water that have been impacted by human activities as they often receive large amounts of nutrients. One plant can multiply to cover one acre in a single growing season forming a dense strand. So, with the combination of its free-floating habit, rapid vegetative propagation, and ability to survive on mud during periods of low water levels, E. crassipes has been able to naturalize in a wide variety of aquatic habitats.

Therefore, the correct answer is option D.