Representation of Potato Virus Y control strategies in current and past extension literature

The aphid-vectored Potato virus Y (PVY) is currently seen as an important limiting factor in the production of potatoes in many countries. Using a contentanalysis approach, we investigated the German extension literature for recommendations regarding the control of PVY. Media included articles from periodicals addressing farmers and agricultural textbooks published in the last five decades (1955–2004). In the current literature (1995–2004), the clearly dominating strategy was found to be insecticidal control, although this strategy has been subject to some criticism in the scientific literature. Over the last five decades we also found a strongly increasing representation of insecticidal strategies. Furthermore, over this period of time, information diversity, measured as the number of different strategies proposed per article or per textbook, decreased consistently