Some of these fungi effectively compete for foliar nutrients with the needlecast fungi and thus may inhibit the completion of the needlecast life cycle. Fir-fern needle rust, Uredinopsis sp. Management Photo 14. Needlecast disease on a forest-grown balsam fir seedling. Varying levels of needlecast may be observed in forest grown stands and on intensively managed sites, such as Christmas tree plantations.
Most injury occurs on small trees growing in cool, moist locations.
Symptoms may be observed one to three years following a wet growing season. Disease is most prevalent in low-lying areas, shaded areas and areas where trees are crowded together. Areas where young balsam fir are surrounded by tall fir can be an ideal environment for high levels of disease. Young fir trees near windbreaks and trees adjacent to densely forested areas are commonly infected. Control is usually not necessary because weather conditions and competition from other fungi keep the damage below serious levels.