The relationship between aphid dynamics and two prominent potato viruses (PVY and PLRV) in seed potatoes in Hungary

An aphid and virus survey was conducted in Hungary yearly between 1993 and 2000. Aphid flight was monitored with yellow pan traps. Virus infection in seed potato progeny tubers was tested with Double Antibody Sandwich ELISA and varied between 0.75-31.8% (potato virusY, PVY) and 0-13.25% (potato leaf roll virus, PLRV). A simple linear regression analysis showed that the factors examined, i.e. total aphid number, vector number, cumulative Vector intensity and age-corrected vector intensity had significant effects on the proportion of PVY and PLRV infected progeny tubers in seed potato fields. In 4 of the 8 years, when cumulative vector intensity (an index that describes vector abundance and their propensity to transmit the virus) did not reach the value of 10 by the end of June, PVY and PLRV infection of progeny tubers remained below 5.2% and 1.7%, respectively. The forecasting method based on cumulative vector intensity was suitable to forecast virus threat to seed potato. (C) 2002 Elsevier Science Ltd. All rights reserved.