What factor can contribute to the spread of viral diseases in plants?

The spread of viral diseases in plants can be significantly influenced by insect vectors. Insects such as aphids, whiteflies, and leafhoppers can carry and transmit viruses from one plant to another. These insects feed on the sap of plants, and during this feeding process, they can introduce viral particles into the plant tissues. Since many viral diseases can be asymptomatic in their early stages, it can lead to widespread infection if insects are not managed properly.

In contrast, while overwatering, soil acidity, and excessive sunlight may create stress or unfavorable growing conditions for plants, they do not directly contribute to the transmission of viral diseases. These factors might affect plant health or susceptibility to diseases in general, but the mechanism of viral transmission is specifically tied to the activity of insect vectors. Understanding the role of these vectors is crucial for implementing effective pest management strategies to mitigate the spread of viral diseases in crops and ornamental plants.