Which of the following is NOT an abiotic disease cause?

• A. Water stress.
• B. Mechanical injury.
• C. Fungal infection.
• D. Pollution.

Answer: (C)

Abiotic disease causes are non-living stresses that injure plants, such as water stress, mechanical injury, and pollution. These factors disrupt plant function without involving any organism. A fungal infection is caused by a living organism—a fungus—so it is a biotic disease cause, not abiotic. Therefore, a fungal infection is not an abiotic disease cause. This distinction helps guide management: abiotic issues are addressed by environmental and cultural changes, while biotic issues require disease-control methods targeting the pathogen.