Texas FFA Nursery Landscape Practice Exam

What is the term for the effect when some plants release chemicals into the soil that inhibit the growth of surrounding plants?

1. Chemical Synpathy

2. Allelopathy

3. Reduction Oxidation

4. Hormonal Redaction

The correct answer is: Allelopathy

The correct term for when certain plants release chemicals into the soil that inhibit the growth of surrounding plants is allelopathy. This phenomenon involves the secretion of allelochemicals, which can affect germination, growth, and development of nearby plant species. Allelopathy can be a natural strategy for plants to reduce competition for resources such as water, nutrients, and sunlight. For example, some trees, like black walnut, produce juglone, a chemical that can be toxic to many other plants that grow nearby. This is an adaptation that can help ensure the survival of the allelopathic plant by limiting competition. The other terms in the options, such as chemical sympathy, are not widely recognized in the context of plant interactions and do not accurately describe this phenomenon. Reduction oxidation and hormonal redaction also pertain to different biological processes that do not involve the inhibitance of growth in surrounding plants due to chemical release. Thus, allelopathy is the precise term that encapsulates this interaction in the plant kingdom.