The most effective method of controlling or preventing viral diseases in plants is by

The most effective method of controlling or preventing viral diseases in plants is by planting resistant varieties. This is because resistant varieties of plants are genetically modified to be immune or less susceptible to the virus, which means they are less likely to be affected by the virus or can recover from it quickly without the need for chemical treatment. This approach is more sustainable and environmentally friendly as it reduces the need for chemical pesticides, which can harm beneficial insects and other organisms, as well as contaminate the soil and water. Therefore, planting resistant varieties is a more reliable and long-term solution for preventing the spread of viral diseases in plants.