Fusiform Rust
HIGHCronartium quercuum f. sp. fusiforme
Overview
The most damaging disease of loblolly and slash pines in the southeastern US. It causes spindle-shaped galls on stems and branches that weaken trees and make them susceptible to wind breakage. Oaks serve as the alternate host.
- Type
- Fungus
- Severity
- HIGH
- Source
- USFS
Symptoms
Spindle-shaped swellings (galls) on main stem and branches, bright orange spore masses on galls in spring, stem breakage at gall sites, pitch seeping from galls, canopy dieback above girdling galls
Affected Species
Geographic Spread
Treatments
Plant Resistant Seed Sources
Use of genetically improved loblolly pine seedlings from rust-resistant families in reforestation. Seed orchards have been developed to produce planting stock with significantly reduced rust incidence.
Prune Infected Branches
Removal of branch galls before they reach the main stem can prevent stem infections. Most effective on young plantation trees during the first few years of growth.
Recommended Products & Tools
Helpful supplies for managing Fusiform Rust. Always read and follow label directions, and confirm a diagnosis before treating.
Broad-spectrum protectant for many fungal leaf and bark diseases.
Preventive spray for needle cast, leaf spots, and blights.
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Frequently Asked Questions
What is Fusiform Rust?
The most damaging disease of loblolly and slash pines in the southeastern US. It causes spindle-shaped galls on stems and branches that weaken trees and make them susceptible to wind breakage. Oaks serve as the alternate host.
What are the symptoms of Fusiform Rust?
Spindle-shaped swellings (galls) on main stem and branches, bright orange spore masses on galls in spring, stem breakage at gall sites, pitch seeping from galls, canopy dieback above girdling galls
Where is Fusiform Rust currently found?
Fusiform Rust is currently active in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, Virginia. It has been reported in 11 total states across the United States.
What plants are affected by Fusiform Rust?
Fusiform Rust affects Loblolly Pine, Red Oak, White Oak. Susceptibility varies by species.
How do I treat Fusiform Rust?
Treatment options for Fusiform Rust include: Plant Resistant Seed Sources, Prune Infected Branches. Treatment approaches may include chemical, biological, cultural, and mechanical methods depending on the severity and context.
Compare with Similar Ailments
Not sure if it's Fusiform Rust? Compare it side-by-side with similar ailments.