Comprehensive Strategies to Manage Potato Virus Y in Potato and Eradicate the Tuber Necrotic Variants - ID
Potato virus Y (PVY), once managed effectively by strict seed certification practices, has reemerged as a serious disease problem in the seed potato crop. The seed potato industry has identified PVY as its most serious disease problem and has set goals to reduce PVY incidence below tolerance limits set by seed certification programs, and to eliminate the new tuber necrotic isolates. Our overall objective in this proposal is to refine the current PVY management strategies used by growers and seed certification agencies to reduce virus levels in seed stocks and spread of virus within the crop. Specifically, we will: a) Assist seed certification agencies to amend current practices and improve their ability to detect, monitor and eliminate PVY from seed stocks. b) Assist breeding programs to develop improved methods to screen for PVY resistance and symptom expression. c) Assist growers to develop cost effective, on-farm virus control strategies. Reducing the overall incidence of PVY to manageable levels and eliminating the tuber necrotic strains will require an adjustment of seed certification practices and a more aggressive use of on-farm management strategies by both seed and commercial potato growers. Similar strategies have been successful in eliminating other potato pathogens from seed production by learning important control points for each of the pathogens, implementing control measures on farms, and making appropriate changes in seed certification and regulatory practices. The goal of this proposal is to achieve a similar level of control for PVY. The expected outcomes and deliverables of our proposed research include: 1. Improved diagnostic tests capable of differentiating all the PVY strains affecting U.S. potatoes. 2. Educational training aids for seed inspectors and growers to recognize all the various foliar and tuber symptoms caused by the new PVY strains. 3. Information back to each participating seed programs on the PVY strains collected from their state. 4. Alternatives to current post harvest test methods, including a comprehensive economic analyses of the different methods currently in use and for those developed in this proposal. 5. Knowledge of the susceptibility of the major U.S. potato varieties to potato tuber necrotic ringspot disease cause by the recently introduced necrotic and recombinant strains of PVY. 6. Establishment of regional trials to evaluate susceptibility, symptom expression, and resistance in varieties and advanced breeding lines to the range of PVY isolates now present in the U.S. 7. Improved minituber production methods that would allow varieties to reach the market earlier and reduce the potential for PVY infection of minituber crops planted in the field. 8. Forecast and economic models that relate the levels of PVY in seed lots of major cultivars to the levels of PVY incidence determined in the field and harvested tubers. 9. New information on the aphid transmission efficiency of the new PVY strains to help predict the likelihood of spread of these strains within and between crops. 10. New information on the efficacy of new antifeedant compounds that could prevent aphid inoculation of PVY to potato.