Tag: deforestation and conservation

Questions Related to deforestation and conservation

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

  1. Eichhornia

  2. Dactylis

  3. Parthenium

  4. Ageratum


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 

  1. 2, 4 - D

  2. 2,4,5 - T

  3. IAA

  4. ABA


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

  1. Typha latifolia

  2. Trapa bispinosa

  3. Cyperus rotundus

  4. Eichhornia crassipes


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.

Weeds affect the crop plants by

  1. Killing of plants in field before they grow

  2. Dominating the plants to grow

  3. Competing for various resources of crops causing low availability of nutrients

  4. All of the above


Correct Option: C
Explanation:

Weeds are nothing but unwanted crops that grow along with the main crop. Thus, they compete with the main crop for sunlight, water, nutrients, and space and thus reduce the resources available to them. In this way, they hamper the growth of the main crop.

So, option C is the correct answer.

................. helps in weed control.

  1. Mono cropping

  2. Multi cropping

  3. Both A and B

  4. Crop rotation


Correct Option: D
Explanation:

  • Rotating crops with ones that kill weeds by choking them out, such as hemp and other crops, can be a very effective method of weed control. 
  • It is a way to avoid the use of herbicides and to gain the benefits of crop rotation. 

Therefore, the correct answer is option D.

Weeds compete in which of the following with crop plants.

  1. Sunlight

  2. Space

  3. Nutrients

  4. All of the above


Correct Option: D
Explanation:

The unwanted plants which grow in field along with the crop plants are termed as weed. They are harmful for the crops as they compete for nutrients, space and sunlight with them.

___________ is an example of weeds.

  1. Wild oats

  2. Mango

  3. Lemon grass

  4. Oak


Correct Option: A
Explanation:

The unwanted plants which grow in field along with the crop plants are termed as weed. They are harmful for the crops as they compete for nutrients with them.

Troublesome American water weed found in India is

  1. Eichhornia

  2. Trapa

  3. Cyperus

  4. Typha


Correct Option: A
Explanation:

The  Eichhornia , commonly known as common water hyacinth, is an aquatic plant native to the Amazon basin, and is often a highly problematic invasive species outside its native range . It grows at an alarming rate and spreads on the surface of the water body. This cut out of the light and it also causes an increase in the oxygen demand. Thus, causing the death of fishes and other aquatic organisms. 

So the correct answer is 'Eichhornia

Congress grass is

  1. Cynodon dactylon

  2. Digitaria purpurea

  3. Cymbopogon citratus

  4. Parthenium hysterophorus


Correct Option: D
Explanation:

Congress grass is the common name for Parthenium hysterophorus . It is a species of flowering plant in the aster family, Asteraceae. 

So the correct answer is 'Parthenium hysterophorus'

Which one is a troublesome weed of agricultural fields?

  1. Chenopodium album

  2. Cyperus rotundus

  3. Parthenium hysterophorus

  4. Eichhornia crassipes


Correct Option: C
Explanation:

Parthenium hysterophorus is commonly called as congress grass or gajar ghass .It is a species of flowering plant in the aster family, Asteraceae. It is native to the American tropics. This weed is equally dangerous for all flora and fauna. It is highly dangerous for humans. It utilizes most of  the nutritious substances from soils, thus converting fertile ground into unfertile ones.

So the correct answer is 'Parthenium hysterophorus'