Antignus, Y., Department of Phytopathology, Virology Unit, ARO, The Volcani Center, Bet Dagan, Israel

Viral pathogens form an important group of obligatory parasites of plants. About 977 plant viruses have been described and classified in 14 families and 70 genera. This group of pathogens has complex interactions with their host plants and vectors due to their integration in the molecular mechanisms of living cells, interfering with our ability to manage the malfunctions of virus infected plants by curing means. These constraints led to the perception that the best protection from virus diseases is by prevention. Many cultural procedures used for virus control are aimed at eradicating or altering one or more of the primary participants in the transmission process (vector, virus source plants, and the crop) or preventing their coming together. Part of these control measures were devised to reduce to a minimum, the number of inoculative vector individuals that are active in the crop or interfere with the transmission process at any of its phases, thereby arresting virus spread. Advances in plant virology and a better understanding of plant vector interactions provide strategies based on the formation of mechanical and optical barriers that interfere with the ability of the viral pathogen or its vector to reach the plant and initiate an epidemic. © 2012 Elsevier Inc.