The Christmas Tree:
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 Studies relating to the etiology and management of this disease are currently underway in Ireland and the PNW. The development of procedures to induce CSNN under controlled conditions would make it possible to utilize seed obtained from controlled crosses between CSNN susceptible and resistant parents in seed orchards to obtain additional information concerning the genetic control of this important disorder of noble fir Christmas trees. Results from preliminary studies also indicate that it may be possible to reduce the severity of this disease with foliar applications of calcium metalosates or the plant growth hormone Propel.

Interior needle blight syndrome
Interior needle blight is the most important needle disease of noble fir Christmas trees (Chastagner 1997). With the increased production of noble fir in the PNW, this disease is becoming more common. Trees affected by this disease are generally unmarketable. In 1998, one grower lost an estimated $1.4 million dollars because of damage caused by this disease. Although several fungi can be associated with diseased needles, an undescribed species of a Mycosphaerella-like fungus is most commonly found on diseased needles.

Symptoms of this disease are most prominent during late summer and fall. They consist of random browning of older needles, mostly on lower branches. Eventually, all of the needles, except current season growth, can be damaged.  This disease also occurs on grand fir in the PNW. Initially, symptomatic needles tend to remain firmly attached to the branch. Small black fungal fruiting bodies are present on the undersides of the needles. Although this disease occurs most commonly on larger trees, it can occur on young trees, particularly when they are inter-planted among older diseased trees.