Which statement best defines the relationship between competition and allelopathy in plants?

• A. Allelopathy is the interaction between plants for space, nutrients and light.
• B. Competition is the interaction between plants for space, nutrients, moisture and light, while allelopathy is when one plant produces chemicals that inhibit the establishment and growth of others.
• C. Both terms describe insect-pest interactions.
• D. Competition is chemical inhibition of other plants; allelopathy is competition for resources.

Answer: (B)

The key idea is distinguishing two ways plants influence each other: competition and allelopathy. Competition refers to plants vying for limited resources like space, nutrients, moisture, and light; when these resources are scarce, growth and survival are constrained simply by sharing them. Allelopathy is a separate mechanism where a plant releases chemicals into the environment that directly inhibit the establishment, germination, or growth of neighboring plants, sometimes even when resource competition is not the main factor.

So the best statement captures both parts: competition is about acquiring resources, while allelopathy involves chemical inhibition of others. The other options mix up these concepts or describe unrelated interactions (such as insect-pest interactions) or invert the definitions.