Which statement describes plant disease vs disorder?

• A. Diseases are caused by pathogens and can be spread from plant to plant.
• B. Disorders are caused by pathogens
• C. Diseases are caused by insects
• D. Disorders are caused by too little water

Answer: (A)

Plants get diseases from living agents—fungi, bacteria, viruses, or nematodes—and these diseases can move from one plant to another or spread within a population. That makes disease a pathogen-driven issue with potential for transmission, setting it apart from disorders, which arise from nonpathogenic factors like environmental stress, nutrient imbalances, or chemical injury. The statement that diseases are caused by pathogens and can spread among plants captures this key difference. Other options misattribute causation—disorders aren’t caused by pathogens, diseases aren’t caused by insects (insects may transmit or cause damage but aren’t the disease itself), and saying disorders are caused by too little water is an oversimplification that doesn’t define the broader distinction between disease and disorder.