56 BULLETIN" 479, U. S. DEPARTMENT OF AGRICULTURE. 
a trench ; the " Michigan board " only with trenches which are con- 
structed by excavating the soil. A single "Mast board" is better 
adapted for use with all sizes of seedlings, if they are of uniform 
development, than a single "Michigan board." With the "Mast 
board" the most efficient man for trenching, threading, and- trans- 
planting can be detailed to those duties, while with the " Michigan 
board " each man performs all of the operations. When the " Mast 
board" is used with seedlings which are not of even development, 
the smaller ones get displaced easily or lost out or, in the process of 
tamping the dirt around the roots, are pulled down too deeply into 
the trench. With both boards there is some danger of pulling the 
tops off the seedlings as they are released, but this is more pro- 
nounced with the " Michigan " than with the " Mast board." Under 
the greatest variety of conditions it seems that the " Mast board " is 
preferable to the " Michigan." * Where the danger of drying out the 
roots of the seedlings is very great, the "Michigan board" should 
prove the better of the two. Using either board an efficient crew can 
average from 4,000 to 5,000 plants per day per man, and a record 
as high as 8,500 plants has been made at the Uinta Nursery with a 
board of the Mast type. 
The " Yale board " is a modification of the Mast boards differing 
from it principally in that the slat which holds the seedlings in place 
is attached to the two hinged handles. The slat swings over to rest 
against the seedlings in much the same manner as when leather 
hinges are used with the "Mast board." The Yale type of board 
used at the Savenac Nursery is provided with spring clamps which 
press the slat against the seedlings and make knobs or buttons un- 
necessary. These clamps are conducive to greater speed in the trans- 
planting operation. The two-men crews using these boards average 
12,000 trees per man per day at this nursery. 
Another board which is cheap, efficient, and used extensively is 
made simply by tacking a thin hardwood strip 2 or 3 inches wide 
on the flat undersurface of a 5 or 6 inch board, so that its edge will 
project about an inch beyond the edge of the wider board. In this 
projecting edge notches are cut to receive the seedlings. When 
threaded, the seedlings are held in place by means of strong elastic 
twine stretched in front of them from one end of the board to the 
other. 
Planting boards are usually 6 feet long, to conform to the most 
common width of transplant beds. At the Converse Flats Nursery 
boards 8 feet long and at the Savenac Nursery boards 8-J feet long 
are used. At the latter nursery the rows run lengthwise, and the 
greater length of board is quite advantageous. 
