34 DEPARTMENT BULLETIN 1425, U. S. DEPT, OF AGRICULTURE 
SPECIES EMPLOYED AS SPECIAL CROSSERS 
Various species are used as special crossers. In the Inland Em- 
pire the larch-fir strip is generally employed, although cedar and 
white fir are used to some extent. The white-fir crosser is most com- 
mon in the California pine region, Douglas fir being second in im- 
portance for this purpose. Douglas fir is also the chief species used 
in the redwood territory. In the Douglas fir region the practice of 
self-crossing stock fixes the kind of crosser used. | 
At any plant, availability of suitable species and grades plays 
an important part in the kind of crossers used. But within such 
limitations, three considerations should serve as guides. Where pine 
is to be seasoned, susceptibility to stain is of first importance; ob- 
viously, species and grades which do not favor stain development 
should be selected. Mechanical properties which will enable the 
crosser to stand up under the usual wear and tear incident to such 
use are also necessary. And the value of the material utilized of 
course bears directly upon the investment which must be carried, 
as well as upon the amount of the actual losses due to breakage and 
other forms of depreciation. 
CONDITION OF THE CROSSER 
It is customary at a majority of plants to use special crossers_ 
repeatedly until they are worn out. Some of the more progressive 
companies, however, attempt systematically to dispose of this crosser 
stock after it has been used three or four times. This is a very 
desirable practice, especially in yards where pine is handled. Not 
only does this permit the sale of such stock before it is seriously 
depreciated (probably a drop of one grade on the average), but 
it also avoids the possibility that with prolonged use the crossers may 
become a source of blue-stain infection. Although the crossers may 
be made of species not susceptible to blue-stain development, their 
use on stain-infected pine stock and careless handling and storing 
about the yard soon results in their collecting blue-stain spores which 
readily transmit new stain infections to the piles of freshly cut pine. 
Actual comparisons to determine the effect of the age of the crosser 
upon crosser-stain development showed that stock piled upon old 
crossers was stained two-and-a-half times as much as that piled on 
new seasoned crossers. This same test brought out the fact that the 
use of green crossers resulted in four times as much crosser stain as 
did the use of new dry crossers. Investigation also indicates that 
a rough crosser causes less stain than a surfaced crosser. Unques- 
tionabiy, rough seasoned crossers which are disposed of after a short 
period of use will give the most satisfactory seasoning results. 
PLACEMENT OF THE CROSSER 
After the general plans for crossing stock has been settled, stand- 
ard methods for the actual placement of the crossers should be 
adopted. Periodic yard checks are then necessary to see that the 
prescribed standards are being carried out in practice. The place- 
ment of crossers, as practiced throughout the West, embraces both 
good and bad practice. One of the most general violations of good 


