Cedar-Apple Rust - Ask Extension
Hello.
We have several apple trees with Cedar-Apple Rust and about 20 small Junipers on our property. We believe they have Cedar-Apple Rust
Wh...
Knowledgebase
Cedar-Apple Rust #870285
Asked May 27, 2024, 2:49 PM EDT
Hello.
We have several apple trees with Cedar-Apple Rust and about 20 small Junipers on our property. We believe they have Cedar-Apple Rust
What is the best way to treat this? Also, when?
Thank you!
Clinton County Michigan
Expert Response
Hello,
Cedar-apple rust is a fungal disease that requires apple (or crabapple) and eastern red cedar (Juniperus virginiana) to complete its life cycle. Here are the best practices for managing Cedar-Apple Rust, as recommended by Michigan State University (MSU):
Remove Alternate Hosts: Eliminating red cedar trees near your orchards can help reduce disease pressure. However, since the infective spores can travel on air currents for miles, removing all sources of disease might be difficult. More information at this link:
https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust
Pruning: Pruning the “cedar apples” from cedar trees is an alternative to removing the tree. This can help to prevent the spread of the disease. More information is at this link:
https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust
Fungicide Application: Fungicides are typically applied from tight cluster through petal fall for apple trees. For the cedar or juniper host, sprays should be applied when spores are being released from the lesions on the apple leaves, usually three times at 2-week intervals beginning in mid-July. Possible fungicide choices for apple and cedar hosts include Ferbam and Mancozeb. More information at this link:
https://archive.lib.msu.edu/DMC/Ag.%20Ext.%202007-Chelsie/PDF/e1441-1980.pdf
NOTE: Read the label and follow recommended application instructions whenever a pesticide/fungicide chemical is used. Do not misuse or abuse pesticide/fungicide chemicals.
Timing: The best time to treat Cedar-Apple Rust is when the disease is active. This is typically in the spring following a warm rain on junipers, when the galls produce orange telial horns. On apples, treatment should begin at tight cluster through petal fall. More information is at these links:
https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust
https://www.canr.msu.edu/news/cedar_apple_rust_a_tale_of_a_fungal_disease_with_two_hosts
Follow the specific guidelines and recommendations provided by MSU extension services to effectively control and manage Cedar-Apple Rust in your area. Regular monitoring and timely treatment are key to managing this disease.
Additional information at these links:
https://archive.lib.msu.edu/DMC/Ag.%20Ext.%202007-Chelsie/PDF/e1441-1980.pdf
https://www.canr.msu.edu/news/creepy_orange_fungus_attacking_junipers
I hope this helps!
Cedar-apple rust is a fungal disease that requires apple (or crabapple) and eastern red cedar (Juniperus virginiana) to complete its life cycle. Here are the best practices for managing Cedar-Apple Rust, as recommended by Michigan State University (MSU):
Remove Alternate Hosts: Eliminating red cedar trees near your orchards can help reduce disease pressure. However, since the infective spores can travel on air currents for miles, removing all sources of disease might be difficult. More information at this link:
https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust
Pruning: Pruning the “cedar apples” from cedar trees is an alternative to removing the tree. This can help to prevent the spread of the disease. More information is at this link:
https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust
Fungicide Application: Fungicides are typically applied from tight cluster through petal fall for apple trees. For the cedar or juniper host, sprays should be applied when spores are being released from the lesions on the apple leaves, usually three times at 2-week intervals beginning in mid-July. Possible fungicide choices for apple and cedar hosts include Ferbam and Mancozeb. More information at this link:
https://archive.lib.msu.edu/DMC/Ag.%20Ext.%202007-Chelsie/PDF/e1441-1980.pdf
NOTE: Read the label and follow recommended application instructions whenever a pesticide/fungicide chemical is used. Do not misuse or abuse pesticide/fungicide chemicals.
Timing: The best time to treat Cedar-Apple Rust is when the disease is active. This is typically in the spring following a warm rain on junipers, when the galls produce orange telial horns. On apples, treatment should begin at tight cluster through petal fall. More information is at these links:
https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust
https://www.canr.msu.edu/news/cedar_apple_rust_a_tale_of_a_fungal_disease_with_two_hosts
Follow the specific guidelines and recommendations provided by MSU extension services to effectively control and manage Cedar-Apple Rust in your area. Regular monitoring and timely treatment are key to managing this disease.
Additional information at these links:
https://archive.lib.msu.edu/DMC/Ag.%20Ext.%202007-Chelsie/PDF/e1441-1980.pdf
https://www.canr.msu.edu/news/creepy_orange_fungus_attacking_junipers
I hope this helps!
