26 
THE NATIONAL NURSERYMAN. 
PRACTITIONER'S VIEW . 
Experience of Captain R. S. Emory, of Maryland, in the Sup¬ 
pression of San Jose Scale—First to Use Whale-oil Soap 
— A Prominent Pear Grower Gives Advice. 
At the recent meeting of nurserymen, horticulturists and 
entomologists in Baltimore, Md., Captain R. S. Emory, Chester- 
town, Md., one of the most successful pear growers in this 
country and the first to use whale-oil soap in the suppression 
of the San Jose scale, read a paper on that subject. Captain 
Emory has used over thirty-four barrels, nearly 14,000 pounds^ 
of whale-oil soap in his orchards fighting this pest during the 
past four years. 
We have heard much from the professional side ; now let us 
consider a few words from the practitioner. 
Captain Emory referred to the alarm felt in many sections 
regarding the scale and emphasized the statements of entomol¬ 
ogists as to the danger of its spreading to all parts of every 
state. He thinks it a much more troublesome pest than the 
codling moth, pear psylla, midge or Colorado beetle. Upon 
the subject proper of his paper Captain Emory said : 
“While whale-oil soap, in my experience, has held this pest 
in check and reduced it, in no single instance has it completely 
destroyed it on old bearing trees. Furthermore, I do not be¬ 
lieve there ever will be a wash found that will completely eradi¬ 
cate it. I have thoroughly tried all the washes that have been 
recommended for the destruction of this pest, and from my 
own practical experience I prefer to use whale-oil soap. This 
substance, when properly applied, will destroy every scale it 
touches. On young, smooth-barked trees not fruiting, the 
soap can be applied at the rate of two and one-half pounds to 
a gallon of water, but on bearing trees the amount should be 
reduced to two pounds to a gallon, as the stronger mixture 
invariably destroys the fruit buds. As I have said before, I 
do not believe that any wash can be applied so thoroughly that 
it will destroy every solitary insect upon a badly infested tree, 
from the fact that the creatures are so very small and seclude 
themselves under bark, in cracks and crevices, and in places 
where they cannot be reached by any spraying. 
“Professor Johnson informs me that he has located it in 
sixteen counties in Maryland, from Washington in the north¬ 
west to Somerset in the southeast. In these counties there are 
forty infested localities, representing seventy orchards and 
nurseries, as compared with the eighteen reported a year ago. 
In these orchards there are 1,442,299 trees growing, of which 
46,891 are infested with the San Jose scale. 40,367 of these 
have been killed outright by the pest, and have been dug up 
and destroyed, leaving in the orchards of the state still stand¬ 
ing 6,512 trees. Any one reviewing these facts must be struck 
with the magnitude of this subject, if they stop to consider the 
great horticultural interests of this state. The pest must be 
checked and controlled, or it will certainly ruin an industry 
that s'tands very prominent in this state. 
“ There is much to be done experimentally for the destruc¬ 
tion of this insect. The only remedies I have seen recom¬ 
mended besides whale-oil soap worthy of trial, are kerosene 
emulsion and pure kerosene applied on a clear, bright, sun¬ 
shiny day. In company with Professor Johnson I have tried 
both these remedies, and found at least twenty per cent, of the 
insects alive several weeks after the applications were made. 
The results were so unsatisfactory that I had the trees re¬ 
treated with whale-oil soap, and in the face of this heroic 
measure some of the insects still survive on those identical 
trees. In spite of this, one of the entomologists mentioned 
above tells us there is “little cause of alarm,” and places great 
stress upon the wash he recommends (pure kerosene), implor¬ 
ing his readers not to rely on laws and conventions to do the 
impossible. He undoubtedly has an ax to grind—at any rate, 
I am perfectly willing to ask this association if the fruit grower 
has any cause of alarm ? Does he need any protection for the 
preservation of his orchards, and the great fruit industry of 
the state ? 
“I believe I was the first to use whale oil soap as a remedy 
against the San Jose scale, and I have fought this insect per¬ 
sistently with that substance since 1892. Since 1895 I have 
used the soap in the form of a spray, and so completely 
destroyed the insects that less than a dozen living ones were 
found after many hours search by a deputy from the U. S. 
Department of Agriculture, and it was thought for a time that 
it would not be necessary to spray the orchard again. The 
spraying, however, was continued the following year, and not 
a living insect was found during the early part of the season 
of 1896, but late in the fall they were abundant throughout 
the orchard on, many trees, even showing conspicuously on the 
fruit. Having tried and done everything possible in the way 
of sprays for the destruction of this pest, after talking with 
Professor Johnson and hearing of his success with hydrocyanic 
acid gas for the destruction of the San Jose scale upon 
nursery stock, I decided to try this method in my orchard. 
The work was to be purely experimental, and Professor John¬ 
son assumed charge of the operations There were many 
difficulties in the way, the greatest of which was a lack of 
funds by the department to purchase the necessary outfit for 
the prosecution of the experiments. We borrowed several 
large tents from the U. S. Department of Agriculture, and 
had several others made in Baltimore. The tents received 
from the government were octagonal in form, and were made 
of eight-ounce duck, which was afterwards painted with boiled 
linseed oil, thus making them perfectly gastight. I designed 
another form, which we term the ‘box tent,’ which has a 
square top and a larger base. These box tents were easily 
handled on small trees, but the sheet tents were very much 
more convenient on large trees, as they could be taken off 
with very much more ease and rapidity. 
“We had many difficulties to overcome in this operation, 
and a long series of tests were necessary to ascertain what 
effect various densities of gas had upon the foliage and buds. 
These preliminary experiments were conducted at all hours of 
the day, and some of them at night. This done, others were 
made during cloudy and very disagreeable weather. After 
the preliminary tests were made, Professor Johnson placed the 
work of fumigating a block of Bartlett pears in the hands of 
Franklin Sherman, Jr., one of his students in entomology, who 
voluntarily assisted him throughout the entire period of ex¬ 
perimental work. The tents were easily handled, and two 
ordinary laborers could remove them from one tree to another 
as fast as the chemicals could be prepared and placed for the 
generation of the gas. Each tree was left covered thirty 
minutes, and where the trees were of uniform size, from 
fifteen to twenty trees an hour could be treated. 
“Of course I cannot give the results of these experiments, 
