Galls on cedar and leaf spots on apple are caused by which type of disease?

Galls on cedar and leaf spots on apple are indicative of rust diseases, specifically because rust fungi typically have complex life cycles that involve one or more host plants. In the case of cedar apple rust, the fungus alternates between two hosts: the cedar trees, where it forms galls, and apple trees, where it causes leaf spots.

This relationship is crucial to understand as it highlights how certain diseases are dependent on specific environmental conditions and host interactions. Rust diseases are characterized by distinctive symptoms, such as the formation of galls and lesions, which can help in their identification. Knowing that these gall formations on cedar and leaf spots on apple trees are part of this pathogen's life cycle assists in the development of effective management practices for these diseases.

In contrast, other options discuss different types of plant diseases. Fungal blight generally leads to decay and dieback but does not specifically produce the gall and leaf spot symptoms associated with rust disease. Root rot primarily affects the roots of plants and is characterized by a different set of symptoms, whereas leaf scorch relates to environmental stress rather than a specific pathogen causing galls or leaf spots. Understanding the signs of rust diseases is vital for effective pest management and disease prevention strategies.