Outbreak of Scleroderris canker, European race, in Central Newfoundland: Escape from Quarantine….
G. Warren and G. Laflamme CFS, NRCAN
Introduction:
scleroderris canker is a serious disease of hard pines, causing seedling blight, branch dieback, stem cankers and tree mortality two races of the disease affect pines in North America, the native North American (NA) race and the introduced European (EU) race the NA race causes lower branch dieback and mortality in pines less than 2 m in height the introduced EU race is a very serious disease which causes branch dieback, stem cankers and mortality of mature trees red pine is very susceptible to this disease, Scots and Austrian pine are moderately affected while jack pine is the most resistant
2 - easily identifiable symptoms and signs of Scleroderris canker
- basal needle yellowing - leader candles 3
- black pycnidia - buried cryptopycnidia - multi-celled spores 4 - 1979, first record of Scleroderris canker EU in Nfld. on Austrian pine in St. John’s5
- 1980, quarantine zone established, no movement of conifer stock from area north of Whitless Bay Line -information pamphlet produced on identification, hazard and quarantine zone 6for Scleroderris canker - 1981, severe infection and total mortality of red pine in Torbay plantation, 15 km north of St. John's (within quarantine zone) 7
- mid 1980's, Scots pine dieback and mortality caused by Scleroderris canker EU observed along Salmonier Line and at site of old Back River Nursery 8 - in early 1990's Scleroderris canker infection and limited mortality was observed in a number of mixed pine plantations along the southern shore of Conception Bay - in 1996 major red pine mortality was observed at Upper Island Cove plantation9
- Back River nursery and Conception Bay plantations were outside the quarantine zone - planting stock for all affected plantations came from the Back River nursery - 1998, quarantine zone was extended to all areas east of Route #202, a natural barrier for the Avalon Peninsula, but no public information pamphlet produced10 - research into the Back River Nursery provided information on the source of planting stock and plantations established - report by A.J. Doyle, 1967 "Reforestation in Newfoundland 1937-1952" summarized, the establishment of the Back River Nursery, details of planting stock produced and identified 16 plantations established on the Avalon, Burin and Bonavista Peninsula between 1938 and 1951 - this report indicated all stock at the Back River Nursery was produced from seed, white spruce, white pine and balsam fir of local origin and Norway spruce, red pine, Scots pine and jack pine from Ontario - Scleroderris canker cannot be transmitted by seed - another report by M. Baker and J. Miller-Pitt, 1998 "By Wise and Prudent Measures: The Development of Forestry on Salmonier Line" provided a detailed historical account of the Back River Nursery - in 1939 the Nfld. Forestry Div. received 30,000 seedlings of red, white, jack and Scots Pine, free from the Ontario Government 11
12 - 1998 survey of 16 plantations established with Back River Nursery stock, revealed most plantations in very poor shape, but Scleroderris canker EU was still present in a number of them - majority of red pine had died but the disease was still present and viable in the surviving Scots and jack pine - jack pine is resistant to the disease, whereas Scots pine is moderately susceptible and persists as an endemic carrier until it finally succumbs to the disease
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14 - infected plantations at Sunnyside and on the Bonavista Peninsula were sanitized with expectations of limiting the disease to the Avalon Peninsula and keeping the 1998 quarantine zone in place - the quarantine and natural barrier at the isthmus of the Avalon Peninsula was successful in limiting the spread of Scleroderris canker EU for over 65 years
UNTIL
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- severe red pine mortality was reported in a plantation at Berry Hill Pond 90 km down the Bay D'Espoir highway from the Trans Canada Highway, about 400 km outside the quarantine zone
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- tests have proven the disease to be Scleroderris canker EU - damage assessment revealed the disease had been present for 7-8 yr, and optimum conditions conducive for spore release, dispersal and infection occurred 2-3 years prior to 2007 resulting in the severe damage - forestry personnel from the Bay D'Espoir office commented that locations along the road through the plantation were common camp sites for moose hunters from the Avalon Peninsula in the late 1980's early 1990's - two tall communication towers along the road to the plantation were easy landmarks for hunters to locate the campsites - it is suspected that hunting groups from the Avalon Peninsula brought their own firewood/kindling with them, which would have been readily available from recently killed red pine in the infected Conception Bay plantations
18 Development of an epidemic from 1- a centre of infection, 2 - then on lower branches in the snow over a large area, 3 - followed by the progression towards the top of the crown…under conducive climatic conditions. Infected shoots at year 1 will produce symptoms at year 2 only if conducive climatic conditions are present.
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A = 4 YEARS B = 1 YEAR
B
A
20 UNUSUAL SYMPTOMS for North America : DEAD TOPS at Berry Hill Pond
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multiple cankers on leaders
22 Great number of pycnidia on a single tree, each containing thousands of conidia. Results: extremely high rate of inoculum !
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The spread of the disease showed a new pattern: instead of spreading on lower branches over a large area, it quickly spread towards the top of pine in the centre of infection and spread over the top, and down on lower shoots.
24 Similar damages in Sweden: 400,000 ha
G reen R iver S p acing Trial B H D isk Review Tree G row th & Im p act C a tego ry Sum m ary
Tree G row th/Imp act # trees DB H Std. AIRatio Std. Category (c m ) Dev. D ev.
Normal 37 23.4 4.1 0.57 0.12
Suppression & cont'd 10 17.5 5.5 0.29 0.07 decline
Im p a ct '77 m o d . rec o ve ry 17 19.3 5.8 0.40 0.06
Impa ct '77 po o r recovery 12 13.6 3.2 0.27 0.05
Impa ct '96 po o r recovery 8 17.8 3.5 0.31 0.05
2X Im pact '96, '89 , 10 12.9 2.9 0.19 0.04
3 X Im p a c t '9 6 , '8 9 , '7 7 6 13.8 2.8 0.12 0.02
Total # trees sam pled 120
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If multiple cankers on the trunk = slow progression of the disease. Conducive climatic conditions are not frequent. Ex.: Mortality of red pine, Upper Island Cove, Avalon Peninsula. If no canker on the trunk = fast progression of the disease. Conducive climatic conditions are frequent. Ex.: Berry Hill Pond, North Central Newfoundland 26 RECOMMENDATION
¾breach of the quarantine zone now places the natural red pine stands and numerous, recently planted, plantations at a serious risk of extinction ¾ preventive pruning of red pine is necessary in central Newfoundland because conducive climatic conditions for scleroderris canker, European race, are frequently present ¾communication to the public through information pamphlets, display notices, roadside signage etc., is necessary to maintain the Scleroderris canker quarantine ¾the isthmus of the Avalon Peninsula is a natural barrier with limited alternate access, where quarantine notices, signage and material deposition depots can be setup 27
Thanks to all students and their teachers
28 MOOSE LAND
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