The phenomenon of one plant having a detrimental effect on another through the production and release of toxic chemicals is termed as:

Correct option is C

The correct answer is (C) Allelopathy

Explanation:
• Allelopathy (from Greek 'allelos' meaning each other and 'pathos' meaning suffering) refers to the chemical inhibition of one plant by another.
• The donor plant releases allelochemicals into the environment (through leaf litter, root exudates, or volatilization) that interfere with the growth of 'receiver' plants.
• Common examples include the Black Walnut tree inhibiting nearby vegetation.

Information Booster:
• True Allelopathy: Release of chemicals that are toxic in the form in which they are produced.
• Functional Allelopathy: Release of a precursor that is transformed into a toxin by microorganisms.

Additional Knowledge:
• Synergism (Option A): When two components work together to produce an effect greater than the sum of their individual effects.
• Symbiosis (Option B): A close, long-term biological interaction (can be mutualistic, commensal, or parasitic).
• Mutualism (Option D): A type of symbiosis where both organisms benefit.