MAPLE SIRUP PRODUCERS MANUAL 



weather. The sap will flow from a wound in the 

 sapwood, whether the wound is from a cut, a 

 hole bored in the tree, or a broken twig. 



Date of Tapping 



To establish a rule of thumb that can be used 

 to set the date for tapping sugar maples is not a 

 simple matter. The date should be early enough 

 to assure collecting large early flows of sap (66). 

 Michigan and New York provide sugarmakers 

 with radio weather forecasts of the correct 

 tapping dates (22). A similar service is being set 

 up in other maple-producing States including 

 Massachusetts, Vermont, and Wisconsin. Gen- 

 erally, trees should not be tapped according to a 

 calendar date. In 1953 when this practice was 

 followed, many producers failed to collect the 

 large early flow that resulted from an unsea- 

 sonable, early warm spell. The danger of tap- 

 ping too early is now largely eliminated 

 through use of germicidal taphole pellets (17). 

 When pellets are used, trees can be tapped 

 several weeks ahead of the normal season. 



Selecting; Trees 



Selecting trees for tapping is of greatest im- 

 portance and can be done at any time through- 

 out the year. 



Trees that produce sap with a density of only 

 1° Brix, as determined with a sap hydrometer 

 or refractometer, should be culled. Culling must 

 be done during the period of sap flow (64). If 

 time does not permit testing all the trees dur- 

 ing one sap season, test as many as possible the 

 first year and test the remaining trees during 

 succeeding years. 



Trees selected for tapping should have a 

 minimum diameter of 10 inches at 4V2 feet from 

 the ground (d.b.h.) (fig. 10). 



A good rule (H, 6i) for determining the num- 

 ber of tapholes that can safely be made in a 

 single tree is as follows: 



Tapholes 



Diameter of tree, per tree,' 



inches number 



Less than 10 



10 to 14 1 



15 to 19 2 



20 to 24 3 



25 or more 4 



' Number of buckets. 



PN-4706 



Figure 10. — Measuring the diameter of the tree to deter- 

 mine the number of tapholes the tree will support. 



To undertap a tree reduces the potential size 

 of the crop without any benefit to the tree. On 

 the other hand, to overtap (fig. 11) may seri- 

 ously damage the tree (72, 94). 



Once the trees have been measured, they 

 should be marked so they will not have to be 

 remeasured each season. This can be done by 

 painting a numeral or a series of dots on the 

 tree or by using paints of different colors, such 

 as white for 1 taphole, yellow for 2 tapholes, etc. 



Boring Tapholes 



Tapholes are made by boring with either a ^/e- 

 inch or a ''/le-inch fast-cutting wood bit. Al- 

 though tapholes can be bored by hand with a 

 carpenter's brace (fig. 12), this method is used 

 only for very small operations. 



For large operations, a portable motor-driven 

 drill not only speeds up the operation but also is 

 far less fatiguing. These drills are made in two 

 basic designs, one powered by a gasoline motor 

 and the other by an electric motor. In one of 

 the earlier models that is still popular (fig. 13), 

 the gasoline motor is mounted on a packboard 



