Effect of N, P, and K Fertilization on Yield and Sugar Content of Sap of Sugar Maple Trees

Abstract

Sap yield, sap sugar concentration, and sugar yield data from sugar maple trees collected over 3 years revealed great intra-and interseasonal variations. The effect of N, P, and K fertilizers, applied singly and in combination, affected the yield of sugar by affecting sap yield and/or sap sugar concentration. The combination fer-

Sugar content in the sap of birches, hornbeams and maples in southeastern Poland

“…The sucrose concentrations found both in native Polish maples (A. platanoides, A. pseduplatanus and A. campestre) and in the exotic American species cultivated in SE Poland (A. negundo, A. saccharinum) were similar to mean sucrose concentrations in sugar maples in America (usually around 3-4% [1][2][3][4][5][21][22][23][24]). Sugar proportions in birches were similar to those found in northern Europe (Finland, Lithuania, Russia) but the concentrations were higher; more than double [14][15][16][17]25,26].…”

“…The tree sap sugar concentrations can be affected by time of day, part of flow cycle (beginning/ end of the flow), tree size, age and soil fertility, basal area of ray tissue and weather conditions in the year, or even changes in gas contents in the atmosphere [1][2][3][4]21,23,24]. A variation between individual trees is attributed to genetic factors and was also documented [4,6,22,23].…”

Modelling the effect of climate on maple syrup production in Québec, Canada

“…Yield of maple syrup may vary according to numerous factors including physical tree parameters (Blum, 1973), genetic characteristics (Kriebel, 1989), foliar chemistry (Leaf and Watterston, 1964), soil fertility (Watterston et al, 1963), sap extraction and conversion methods (Morrow and Gibbs, 1969), and management of the production. For example, modernization of collection systems including the use of plastic tubing and vacuum pumping has gained in popularity over the last decades with an expected positive effect on maple syrup yield Koelling et al, 1968).…”

Soil nutrients affect sweetness of sugar maple sap

“…Adding N increased sap sweetness in a study in Ohio (Kriebel, 1961) but had no effect in central New York (Watterston et al, 1963) or New Brunswick (Bary and Roy, 1998). Adding P decreased sap sweetness of trees in central New York (Watterston et al, 1963). Potassium, Ca, and Mg together increased sap sweetness in northern Vermont (Wilmot and Perkins, 2004) but not in northwestern New Brunswick (Bary and Roy, 1998).…”

“…Potassium, Ca, and Mg together increased sap sweetness in northern Vermont (Wilmot and Perkins, 2004) but not in northwestern New Brunswick (Bary and Roy, 1998). Often, N, P, and K are added together, with positive effects (LaValley, 1969;Leech and Kim, 1990) or no effect (Watterston et al, 1963;Wilmot et al, 1995) on sap sweetness.…”