Which disease is caused by Grape fanleaf nepovirus?

The disease caused by Grape fanleaf nepovirus is Grapevine fanleaf. This virus specifically affects grapevines and leads to various symptoms, including leaf distortion, reduced growth, and overall decline in vine health. The name "Grapevine fanleaf" directly indicates the association with this specific virus, highlighting its role as the causal agent.

Grapevine fanleaf is important to acknowledge within the context of grape production, as it can significantly impact yields and quality. Understanding the relationships between specific pathogens and the diseases they cause is essential for effective management and control strategies in viticulture.

The other options listed involve different pathogens or diseases that do not relate to Grape fanleaf nepovirus, which is why they are not applicable in this case.