Which of the following is an abiotic disease cause?

• A. Water stress.
• B. Fungal infection.
• C. Bacterial blight.
• D. Parasitic plant.

Answer: (A)

Abiotic disease causes are nonliving factors that injure plants. Water stress is a classic example because it results from too little or too much water, not from a living pathogen, and it can cause wilting, leaf discoloration, or reduced growth. The other options come from living organisms: a fungal infection involves fungi, bacterial blight involves bacteria, and a parasitic plant depends on another plant for nutrients. Recognizing abiotic stress often involves noting patterns tied to water availability and soil conditions, and it typically improves with proper irrigation and drainage rather than with pest-control measures.