Public Works Foreman - Wayne Dalueg
Public Service Operator - Bernie Knievel
Public Service Operator- Jason Loosemore
Public Works Shop Phone 780-582-4195
More information is available on the Alberta Governement Website: www1.agric.gov.aba.ca - search "Black Knot"
from Manitoba Agriculture - www.gov.mb.ca/agriculture/news/topics/daa63d13.html
Management of Black Knot - www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq7622
Black Knot Factsheet - plantclinic.cornell.edu/FactSheets/black_knot/blacknot.htm
Bronze Leaf Disease of Poplar
Site evaluations of poplar trees are finding that Bronze Leaf Disease or BLD is showing up on Swedish Colmnar Aspen poplar. Both of these ornamental trees are highly susceptible to BLD. The infected leaves turn a reddish-brown colour from the leaf's edge towards the leaf base. The leaf veins and petiole or leaf stem may remain green for a time.
Initially introducted by spores, BLD cannot be controlled by chemicals. It can only be managed through good sanitation practices such as removing leaves, pruning out diseased material, and maintaining good plant health and vigor with adequate water, fertilizer, etc. Diseased plant material should be pruned out below the lowest visible point of infection with trees severely infected or those that have recently died from BLD being removed, burned or buried. Only this will reduce the risk of this disease spreading to other trees.
The diagnosis of this disease is achieved by examining the fruiting bodies of the pathogen. However, this can be difficult because the fungal fruiting bodies only form after an over-wintering period. The infected, over-wintered leaves, with fruiting bodies add a "Bumpy" texture to the leaf. Symptoms of BLD appear in mid-summer. It was originally found in both SCA and Tower poplar plantings in Manitoba. From there it has spread westward. This is thought to be the result of shipping diseased plant material.
This information should be used as a guide. If you suspect BLD, sanitization procedures should be instigated with a follow-up tree and site analysis again during the spring.