28 BULLETIN 1422, TJ. S. DEPARTMENT OP AGRICULTURE 
MORE ECONOMICAL PRODUCTION NEEDED 
A second means of improvement lies in more economical production. 
To this end tapping methods may be improved, the latex handled 
more carefully, and less rubber allowed to go to waste. These 
economies are not at all easy to carry out in an exploitation so little 
controlled as the one in question. They are especially hard to insure 
when an industry is so sadly demoralized as this one. Some 
saving might be effected by expending more time in selecting trees 
for tapping in an estrada. As may be seen by an inspection of Table 
1, some trees give an excellent yield. There are 22 trees which have 
yields of latex of 200 cubic centimeters or more, and these give a 
total yield of 6,749 cubic centimeters; that is, 9 per cent of the trees 
give 30 per cent of the latex. Of trees yielding less than 50 cubic 
centimeters of latex, there are 88 which give a total yield of 2,033 
cubic centimeters of latex. This is 9 per cent of the yield of the 
estrada and is given by 37 per cent of the trees. There are 42 trees 
bearing 20 cubic centimeters or less of latex, and these yield 528 
cubic centimeters. Of these trees the lowest yielding contingent 
makes up 17 per cent of the estrada, but yields only 2.4 per cent of 
the latex. It is easy to see that these 42 trees are not worth tapping 
even though they are directly on the estrada. They should be 
dropped out and other trees added which give a higher return for the 
labor. Obviously, it is not always possible to rearrange estradas so 
that more trees may be available. Sometimes the limitations are 
those of site; impassable streams intervene, etc. If every estrada 
were in tapping it would be more difficult than it is now with idle 
estradas everywhere, so that some rearrangement should not be 
difficult. The seringueiro can well afford a somewhat longer round, 
if he secures a considerably augmented return. There are dozens of 
trees in nearly every estrada which are not worth tapping. With 
these eliminated, there is a chance that the higher yielders may prove 
worth tapping even under present conditions. 
The loss of latex in the average estrada is very great. Much of 
it never reaches the cup, but drips over the edge of the slanting cut 
and runs down the bark or drops to the ground. The lip of the cup, 
which is thrust into the bark at the lower end of the cut, is bent into 
so narrow an angle that it does not form an adequate spout for collect- 
ing the latex. 
The rubber which coagulates on the cut is never removed, though 
in many trees it exceeds the quantity secured from the collected 
latex. Akers (2) considers that this fact has saved the trees of the 
region from ruin, keeping insects and fungi out of the cuts. This is 
probably not the case, because the rubber rarely seals the cuts, at 
least such cuts as are made nowadays. How far the rubber prevents 
insect attack the writer will not venture to say; but he knows from 
experiment that the rubber is of no avail in preventing attacks by 
fungi, because many fungi will grow on latex as a substratum, and 
coagulated rubber is in no way injurious to them. 
Latex is frequently lost also from cups which have broken along 
the seams. Most of the cups used are of flimsy tin and are rather 
poorly soldered. As a consequence of the bending which the edge 
undergoes in the formation of a sharp lip which can be thrust into 
the bark, the seams break open, a fact frequently overlooked by the 
seringueiro who in his haste has little time to look at each cup. 
