What type of plant diseases can be infectious?

Infectious plant diseases are those caused by living organisms that can spread from one plant to another. The correct choice encompasses a range of pathogens—fungi, bacteria, viruses, and nematodes—all of which are known to cause infectious diseases in plants.

Fungi are among the most common pathogens, responsible for diseases such as rust, blight, and mildew, which can spread spores to nearby plants. Bacteria can cause diseases like bacterial wilt and fire blight, often spreading through water or insect activity. Viruses typically infect plants by being transmitted through vectors like aphids or through mechanical means during plant handling. Nematodes are microscopic roundworms that can infect the roots of plants, causing significant damage and transmitting other pathogens.

The other choices refer to non-infectious factors affecting plant health. Stunting, scorching, and leaf distortion describe symptoms that can arise from various stressors, but they do not indicate infectious agents. Herbicides and pesticides, while they may be related to plant health, do not cause infectious diseases; instead, they are chemical controls to manage plant diseases and pests. Soil and water contaminants may lead to health issues in plants, but they do not represent living infectious agents responsible for disease transmission. Thus, the answer appropriately