Khalil Al-Mughrabi1 and Patrice Audy2
Partner: Potatoes New Brunswick
Abstract: Over forty samples of potato leaves and stems infected with late blight were collected from Regions 2A and 5 in New Brunswick. Leaves and stems were cultured on Rye Extract Agar (REA). Various methods were followed to achieve this goal. These included culturing leaf and stem sections directly on REA; single spore transfer and culture on REA; placing infected leaves between 2 halves of a sliced tuber and incubate in plastic bags until infection occurs and then culture on REA. Pure cultures are maintained for long term storage. All of the isolates tested were of the A2 type. Twenty-two isolates collected from New Brunswick between 2000 and 2003 were tested for their sensitivity to fungicides registered for this purpose. Initial results indicated that late blight populations collected in 2003 from the Grand Falls and Fredericton areas are more sensitive to fungicides than those collected in 2001 and 2002. Reasons for these findings are being investigated.
1 NB Department of Agriculture, Fisheries and Aquaculture, Potato Development Centre, 39 Barker Lane, Wicklow, NB, E7L 3S4
2 Agriculture and Agri-Food Canada, Potato Research Centre, PO Box 20280, Fredericton, NB, E3B 4Z7