Vacuum pumping increases sap yields from sugar maple trees
By: by Barton M. B[l]um a[n]d Melvin R. Koelling.
Contributors: Koelling, Melvin R. 1937-; United States. Forest Service.
Series: Research paper NE -- 106.
Publisher: Northeastern Forest Experiment Station, Forest Service, U.S. Dept. of Agriculture
Published: 1968
Place of publication: Upper Darby, Pa
Language: eng
Number of pages: 14
Subjects: Maple syrup; Sugar maple; Sugar maple -- Tapping
Notes: Cover title.

Author's name misspelled on cover.

Bibliography: p. 14.