Using Prescribed Fire to Control Insects And Disease
Prescribed burning can be used to control insects and disease. Brownspot disease (Scirrhia acicola) is a fungal infection that may seriously weaken and eventually kill longleaf pine seedlings. Diseased seedlings tend to remain in the grass stage. Control is recommended when more than 20 percent of the seedlings are infected or when some of the diseased seedlings are needed for satisfactory stocking. Once the seedlings become infected, burning is the most practical method of disease control. Any type of burning that consumes the diseased needles without killing the terminal bud is satisfactory. Burning the infected needles reduces the number of spores available to infect the seedlings. Generally a fast-moving winter heading fire under damp conditions, as exist after passage of a strong cold front, is best. Height growth of the seedlings often begins the first postfire growing season. Reinfection usually occurs quickly if there are infected seedlings in unburned areas near the burned area. If reinfection occurs, additional burns may be needed. However, longleaf is most susceptible to fire immediately after it comes out of the grass stage. Therefore, a reburn will likely kill some seedlings, so such a decision should be made in consultation with experienced personnel.
Prescribed burning seems to reduce problems from Fornes annosus root rot. This fungal disease is less frequent where periodic burns have reduced the litter. The fire alters the microenvironment of the forest floor and perhaps destroys some fruiting bodies and cauterizes tree stumps.
Prescribed fire has been successfully used under very exacting fuel and weather conditions to control cone insects such as the white pine cone beetle (Conophthorus coniperda) while the pest is overwintering in cones on the ground. Prescribed burning costs much less than traditional chemical control methods used to control this beetle.
See also: Prescribed Fire and the Southern Pine Beetle.
Encyclopedia ID: p577
