Question

Given below are two statements:
Statement (I): The combined effect of competition and allelopathy where growth of weeds or crop or both is reduced is called allelomediation.
Statement (II): Allelopathy depends on addition of chemical compounds while competition involves removal of an essential factor from the environment.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true.
• B. Both Statement (I) and Statement (II) are false.
• C. Statement (I) is true but Statement (II) is false.
• D. Statement (I) is false but Statement (II) is true.

Hint:

Recall that allelopathy adds chemicals to the surroundings while competition removes resources from it.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept.
Weeds affect a crop through two separate mechanisms, competition for resources and allelopathy through chemical release. Allelomediation is the term used when both mechanisms act together.

Step 2: Checking Statement I.
Statement I says allelomediation is the combined effect of competition and allelopathy, where the growth of weeds, crop, or both gets reduced. This matches the accepted definition used in weed science, where allelomediation describes the joint outcome of a plant taking up resources and releasing chemicals at the same time.

Step 3: Checking Statement II.
Statement II says allelopathy works by adding chemical compounds into the environment, while competition works by removing an essential factor, such as light, water, or nutrients, from the environment. This is exactly how the two processes are told apart in weed science. Allelopathy adds toxins or inhibitory chemicals through root exudates, leaf leachates, or residue decomposition, while competition takes away a resource that both plants need.

Step 4: Final Answer.
Both statements describe accepted, correct definitions, so option 1 is correct.