Download or read book The Effect of Xylem Age on Volume Yield & Sugar Content of Sugar Maple Sap written by Carter Bradley Gibbs and published by . This book was released on 1969 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the Burlington, Vermont, research unit of the Northeastern Forest Experiment Station, a study was begun in 1966 in an effort to identify the portions of the xylem that produce the most sap and the sap with the highest sugar content. The study revealed that the greatest volume of sap comes from xylem that is about 35 years old, and that the sweetest sap comes from the young xylem just beneath the bark.