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Management Strategies for Reducing Losses Caused by Fusiform Rust, Annosus
Root Rot, and Littleleaf Disease
Robert L. Anderson - Supervisory Pathologist, USDA Forest Service, Southeastern Area, State and Private Forestry, Forest Pest Management, Ashville, N.C., and
Paul A. Mistretta - Supervisory Pathologist, USDA Forest Service, Southeastern Area, State and Private Forestry, Forest Pest Management, Pineville, La.
United States Department of Agriculture, Forest Service, Cooperative State Research Service, Agriculture Handbook No. 597, October 1982.
Fusiform Rust Management Practices
All Other Areas
| Management Practices |
Fusiform Rust |
| A. Use protective chemical treatments. |
Time the first fungicide treatment to coincide with the development of tellia on oak leaves. Water and willow
oak are the best indicators. |
B. Cull seedlings with any obvious
fusiform swellings on the stem. |
Avoid movement of rust-infected stock from the
nursery or cull rust-infected seedlings before planting. |
E. Use seeds or seedlings that are
resistant or less susceptible to
disease. |
Avoid planting rust-susceptible pines on high-hazard sites. (Use figs. 6 and 7 as a guide). Regeneration of high-hazard sites should be done with seeds or seedlings from:
- Rust-resistant slash and loblolly pine seed orchards, or
- Less susceptible species (e.g. longleaf, shortleaf, sand pine), or
- Geographic areas of resistance (e.g. Livingston Parish, LA; east Texas; Maryland; Arkansas) or a mixture of these. Use resistant local sources when possible.
Avoid planting slash pine outside of its natural range. |
| F. Consider altering planting density. |
The planting strategy to reduce the incidence of fusiform rust requires that planting density be increased to compensate for losses. Note that this recommendation conflicts with that made for both annosus and littleleaf. Where more than one disease is being considered, individual management goals will influence the selection of outplanting spacing. |
| G. Modify fertilization practices. |
On moderate- to high-hazard sites, fertilization (which predisposes pines to infection by promoting more succulent tissue) should be delayed until trees are 8 to 10 years old. Lethal fusiform rust infections after age 10 are rare.
On low-harzard sites, fertilization will not increase infection significantly and improved growth will offset the impact of that increase. |
H. Prune or excise fusiform galls and
cankers. |
From midsummer to midwinter, remove limbs with infections more than 3 inches (7.5 cm) and less than 18 inches (45 cm) from the bole. Treat stem infections and branch infections that are 3 inches (7.5 cm) or closer to the stem by completely removing the bark, down to the wood, around the canker. Leave a margin of clear wood at least 1 inch (2.5 cm) on each side and 2 inches (5 cm) above and below the furthest extent of the canker. (Consult Matthews and Anderson 1979 for more details).
Consider pruning forested stands if the practice would bring the stand up to adequate, disease-free stocking. |
I. Reduce oak population when practical
and when not in conflict with other
management practices. |
Consider using management techniques (e.g. hot summer burns before planting or herbicides), which reduce the amount of oak in or adjacent to pine plantings, nurseries, or seed orchards. Indiscriminate eradication of oak trees is not recommended, and careful attention should be given to the value of oaks for wildlife food and habitat, esthetics, and land values. |
K. Remove the most severely affected
trees during thinning operations when
the residual stand will be adequately
stocked. |
The higher the level of infection in a stand, the more important it is to thin selectively. Infected trees can be allowed to grow for up to 8 years if less than 50 percent of the trunk circumference is cankered.
The following guidelines are recommended for stands that are old enough to thin commercially and that will have adequate stocking (Table 1) after the thinning operation:
- In stands with low levels of rust infection (less than 25 percent of trees with stem infections), remove the most severely stem-cankered trees first, then remove less damaged trees to obtain a residual basal area of 75 to 85 feet² per acre (17 to 19.5 m²/ha) for loblolly and 75 feet² per acre (17 m²/ha) for slash pine.
- In stands with stem infections on 25 to 50 percent of the trees, thin by removing the most severely cankered trees first, and then the less damaged trees.
For stands that will be inadequately stocked (Table 1) because of thinning, regenerate or justify carrying the stand (management option N). |
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