20 
FUMIGATION INVESTIGATIONS IN CALIFORNIA. 
belong to the latter class. The following statement and comparative 
table have been prepared which indicate the wide range of variation 
in these schedules: 
Dosage schedules. — For the information of those who may be inclined to doubt 
the writer's contentions in this bulletin with relation to the generally chaotic con- 
dition of fumigation schedules published in the interests of California citrus growers, 
a table has been prepared which includes nearly all of the more important sched- 
ules, together with a comparative analysis of the same. The dosages for trees of 
given dimensions were duly computed. Having this data at hand and utilizing 
the dosage allotted to each individual tree, it was possible to work out the rate of 
Fig. 10.— A typical California lemon orchard with row of fumigation generators placed ready for use 
the following night. (Original.) 
dosage per 100 cubic feet of inclosed space at which that particular tree was being 
fumigated. This has been done for all trees in the schedules proposed by several 
writers, and the results have been arranged in the latter half of the table. 
A glance at this table will show that the schedules of Morse, Coquillett, and Wood- 
worth were all based on the cubic contents of the trees, which were dosed at a uni- 
form rate, but without regard to the leakage of gas. Large trees are dosed at the 
same rate as small ones, thus giving a lack of uniformity in results. All of the other 
schedules detailed in this table were apparently prepared with little or no regard 
to the cubic contents represented by trees of different dimensions. Although it 
would appear from the table that leakage was taken into account, inasmuch as the 
smaller trees receive a greater rate than the larger ones, proper allowance could not 
be made for this factor without definite consideration of the cubic contents. Con- 
sequently the decrease of rate recommended is in all cases irregular and widely 
removed from a rate proportionate to the actual leakage. The fact that trees in- 
