Which term describes when one plant species suppresses the growth of another?

The correct choice, allelopathy, describes a biological phenomenon in which one plant species releases chemicals into the environment that can inhibit the growth of other plant species. This chemical interaction is often part of a survival strategy, allowing the allelopathic plant to reduce competition for resources such as nutrients, light, and water.

Understanding allelopathy is critical for managing plant communities and agricultural systems, as it can influence crop yields and the diversity of plant species present in an area. Recognizing which plants have allelopathic properties can help in planning planting strategies to either utilize beneficial relationships or mitigate harmful effects in farming and gardening practices.

In contrast, companion planting involves planting different species together for mutual benefit, while plant parasitism refers to one plant living off another, often harming it. Mutualism describes a scenario where two species interact for their mutual benefit, which does not involve the suppression of one by the other. These concepts highlight different types of interspecies relationships, but they do not specifically encompass the suppressive interaction described in allelopathy.