Texas FFA Nursery Landscape Practice Exam

What term is used in horticulture to define plant injury sometimes caused by pesticides?

1. Emulsification

2. Expectoration

3. Eutrophication

4. Phytotoxicity

The correct answer is: Phytotoxicity

Phytotoxicity refers to the toxic effects that certain substances, including pesticides, can have on plants. When a plant is exposed to a chemical agent that disrupts its normal physiological processes, it can lead to symptoms of injury such as leaf burn, stunted growth, or even plant death. Pesticides, which are intended to manage pests but may sometimes be applied improperly or at inappropriate levels, can cause such harmful effects if they are phytotoxic. Understanding phytotoxicity is crucial for horticulturists and landscape professionals as it allows them to use pesticides effectively while minimizing harm to desirable plants. Emulsification, on the other hand, is a process involved in mixing two immiscible liquids, usually not directly related to plant injury. Expectoration refers to the act of expelling substances from the respiratory tract and does not pertain to horticulture. Eutrophication describes the process of nutrient over-enrichment of water bodies, often leading to excessive algae growth, and while it relates to plant health, it is not specific to injury caused by pesticides. Thus, phytotoxicity is the accurate term for plant injury due to exposure to harmful chemicals.