10 



AGRICULTURE HANDBOOK 134, U.S. DEPT. OF AGRICULTURE 



PN^707 



Figiire 11. — Overlapped tree (8 buckets on a 4-bucket 

 tree). Note attempt to tap over large roots. 



PN-170K 



Figure 12. — Boring the taphole at convenient breast 

 height. The hole is 6 inches from that bored the pre- 

 vious season. 



and is connected to the drill by a flexible shaft. 

 In other models, the drill is attached directly to 

 the gasoline motor, which is held in the hand. 



The electric battery-powered drill (figs. 14 

 and 15) is newer than the gasoline-powered 

 drill. It is light and free from vibration and is 

 fast becoming popular. With either a gasoline- 

 or an electric-powered drill, one man can drill 

 holes as rapidly as a crew of two or three can 

 set the spouts and hang the buckets or bags, or 

 install the tubing. 



The hole is bored into the tree, preferably at 

 a downward pitch of approximately 5 degrees. 

 The downward pitch is especially desirable if 

 germicidal pellets are used in the tapholes. The 

 hole is bored 3 inches deep or until stained 

 heartwood is reached. Studies at Michigan 

 State University {57) have shown that a taphole 

 3 inches deep (fig. 16) produces up to 25 percent 

 more sap than a taphole only 2 inches deep. 



The position of the first taphole is selected 

 arbitrarily. The hole should be 2 or 3 feet above 

 the ground or, if there is snow on the ground, 

 as close as possible to this height. This low 

 position is particularly well suited to the use of 

 plastic tubing. The compass location of the hole 

 is not important. Data obtained in New York 

 (m) and in Michigan {16, 93, H, 96) have shovm 

 that the total yield is essentially the same 

 regardless of the compass location of the hole. 

 However, the warm side of the tree is favored. 

 Data also show that the height above ground 

 level has little effect on yield. The best practice 

 is to make the new taphole on successive years 

 6 to 8 inches from the previous year's taphole, 

 working up the tree in a spiral pattern (fig. 17). 

 With this procedure, the producer may tap his 

 tree year after year in different quadrants and 

 avoid striking an old taphole or dead tissue that 

 has been hidden by new bark, either of which 

 would result in a smaller flow and poorer qual- 

 ity sap. 



When plastic tubing is used to collect sap, 

 there is no minimal distance at which the 

 taphole is located above the ground, and an 

 even larger area of the tree becomes available 

 for tapping. This permits a longer interval be- 

 tween periods when a repeat tap has to be 

 made in the same area of the tree. 



