project-report-strategies-for-minimizing-virus-infection-of-potato-crops
This project report combines published information with the results from this work to provide a Decision Support System for minimizing PVY infection.
The project combines close collaboration with participating seed growers. It implements a system of within field aphid trapping and virus testing with complementary experiments designed to provide information to evaluate the risk of virus (principally PVY) infection and examine the merit of various testing strategies for crop management. The experiments were particularly concerned with evaluating the importance of mature plant resistance to PVY infection. The aphid species which have been shown to transmit PVY were given an efficiency index based on their ability to transmit the virus.
Aphid trapping can be a useful management tool for controlling PVY. In the two years prior to the date of this interim report, seed crops were burnt down promptly once a substantial rise in the ‘PVY index’ was recorded and in most crops either no PVY or a low incidence (1- 5 %) was recorded in post harvest tuber tests. The data obtained from these crops allows estimation of conditions which preclude substantial PVY spread but the absence of high incidence of infection limits the potential for modelling PVY ingress. Results from the virus movement experiment carried out over two years have been largely consistent. ELISA tests carried out on leaves and stems gave substantially lower incidence of PVY than the results from tuber tests. The incidence of infection in tubers was negligible for tubers harvested immediately after one week exposure to infection but one week later, infected tubers were detected and the incidence increased after a further week although to a lesser extent. The proportion of tubers infected tended to increase with increase in aphid index up to c. 50 but there was considerable variation in incidence of PVY in relation to aphid indices between exposure dates. Older plants had a lower incidence of infection than young plants, but even for old plants (exposed 6 weeks after emergence) up to 30 % were infected during weeks when the vector index was high. The differences in tuber infection between young and old plants confirms the importance of mature plant resistance for modelling infection in crops
