Determining the Relationship Between Needle Nutrition and Post-harvest Needle Retention in Balsam Fir (Abies balsamea (L.) Mill.)

Abstract

The Christmas tree and greenery trade is a multi-million dollar industry in Atlantic Canada. Christmas trees grown in Nova Scotia are shipped internationally especially, to the United States. This thesis was set out to answer the over-arching hypothesis: pre- and post- harvest needle nutrient content influences post-harvest needle retention. Through a series of experiments it was shown that the pre-harvest needle P, Ca, Mg, Mn, Zn and B contents do not appear to be directly linked to post-harvest needle retention. Alternatively, the pre-harvest needle N, K, Cu and Fe contents significantly, but negatively influenced post-harvest needle retention. By maintaining needle N, K, Cu and Fe concentrations below 1.5 %, 0.55 %, 3.7 ppm and 35 ppm, respectively may extend needle retention in balsam fir. Xylem-fed nutrients negatively influenced needle retention. As well, foliar applications of calcium and zinc citrate did not promote needle retention at the concentrations used.