62 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
where it is tested on a comparatively small scale and with few duplicates 
or repeatings. Here, if it shows promise, it is promoted next season to 
the “continuation plots” where it is tested on a larger scale and usually 
duplicated at least ten times. If in the continuation plots it gives evi¬ 
dence of possessing undoubted commercial value, we endeavor to have 
it tested according to our instructions by a commercial grower. Two 
of the treatments that we have used have reached this latter stage and 
of these one of each have been given an adverse report by one of those 
who tested it—one of these was an official entomologist and one the di¬ 
rector of an experiment station. All the commercial growers secured 
excellent satisfaction from both treatments. 
These four treatments have all been tested in our continuation plots 
for at least three years and accordingly, we have prepared a table show¬ 
ing the average results for these three years, which should show better 
than a single year’s figures the comparative standing of the different 
treatments. 
In considering the factors that affect the price received we have to 
consider not only total weight, but also earliness of maturity. The latter 
is affected by certain treatments or lack of treatment and it is the treat¬ 
ment that produces the greatest weight of earliest maturing cabbage 
that, as a rule, brings the best price, because the greatest price is usually 
received for those cabbage that reach the market first. We have based 
our comparison of the different treatments mainly on the weight of 
head secured, primarily because we sell by weight, but also because it is 
the only really quantitative way to record results. If sufficient dupli¬ 
cates are employed to minimize variations in soil, moisture conditions, 
etc., it undoubtedly gives the most accurate idea of the comparative 
value of different treatments. Along with the total weight of head we 
consider the actual price received from the cabbages from each plot, 
careful records of which are always kept. This is the most practical 
standard of comparison and the one that has the greatest interest for 
the commercial grower. 
In considering these results it should be noted that with the creosote 
and anthracene oil dusts, we have used ordinary clay as a filler. All 
the treatments were applied twice except the tobacco dust-corrosive 
sublimate mixture, which only received a single application. The first 
of these applications was made when the flies first appeared, the second 
a week to ten days later. It should further be noted that all the plants 
were grown under the very best cultural conditions and consequently 
