Which of the following is an abiotic factor affecting plant disease?

Air pollution is recognized as an abiotic factor affecting plant disease because it encompasses non-living elements that can influence plant health directly or indirectly. Abiotic factors are environmental conditions that are not biological in nature; they include physical and chemical components such as weather, soil conditions, and pollution.

Air pollution can lead to stress in plants, making them more susceptible to diseases caused by pathogens. For instance, pollutants can affect photosynthesis and respiration processes, weaken plant structures, or create conditions that foster the development of diseases.

In contrast, the other options pertain to biotic factors, specifically living organisms that can cause disease. Fungi, bacteria, and viruses are all biological agents that directly impact plants by causing infections and diseases, rather than impacting them through environmental conditions. Understanding the distinction between abiotic and biotic factors is crucial in plant pathology and pest management.