Final answer:
Viroids are significant because they cause diseases in plants, leading to severe agricultural economic impacts. Their infection can affect various crops, resulting in crop failures and losses.
Step-by-step explanation:
Viroids are of economic significance because they cause disease in plants. These plant pathogens are small, single-stranded, circular RNA particles that can lead to devastating losses for the agriculture industry. They lack a protein coat and can only reproduce within a host cell. Viroids are responsible for a variety of plant diseases that can result in significant economic damage, impacting crops such as potatoes, cucumbers, tomatoes, chrysanthemums, avocados, and coconut palms.