10 
are set in the square and in the alternate system, respectively. The 
figures in the squares represent the records of the trees fumigated, 
the two upper figures separated by a dash representing the dimen- 
sions of the tented tree and the lower figure the amount of cyanid 
given.” These records are made at the time each tree is fumigated. 
In presenting the dosage table recommended in Bulletin 76 it was 
stated that the amounts of cyanid could be increased from 10 to 25 
per cent with advantage under certain conditions. At the present 
time the authors advise for general use a table (fig. 4) representing 
-. 43-62 
33-47 on RE 
2 eg 
42-50 47-60} 23 
eae reat Lt | 
aie iet 
es 
23 
At Bee Cc DES Fs .1Gar nn 
S. 
Fig. 3.—Diagram of grove with alternating trees; first four rows in process of fumigation with four tents; 
three sets of trees fumigated, the tents being moved from south to north: X, X, X, trees missing. (From 
Morrill.) 
an increase of 25 per cent over the minimum requirements previously 
given in tabular form. This seems desirable, owing to the wide 
variations in the weave of various tenting materials and to the fre- 
quency with which slight winds might interfere with the results. 
MISCELLANEOUS SUGGESTIONS. 
With the gradual extension of the process of fumigation in the 
control of the white fly in Florida and other citrus-growing sections 
of the Gulf coast, the value of a citrus grove will be considerably 
“The amount is according to the dosage table given in Bulletin 76 of this Bureau, 
page 68. 
(Cir. 111] 
