New YorK AGRICULTURAL EXPERIMENT STATION. 271 
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TESTS AT YORKTOWN. 
During the winter of 1900-1901, two series of tests of crude 
petroleum were made at Yorktown, Westchester County, N. Y. 
The petroleum used had a specific gravity of 0.79 (44° on Baumé 
oil scale). Series I consisted of an application of 15 per ct. crude 
petroleum in a mechanical mixture with water as follows: 
(a) One application in December. 
(b) One application in December and one in April. 
(c) One application in April. 
Series II consisted of an application of 25 per ct. of crude 
petroleum in a mechanical mixture with water, under same 
conditions as Series I. In these tests the same spraying outfit 
was used as in previous tests. 
Conditions.— The tests were made on plum, peach; pear and 
apple. The plum orchard was the center of infestation, to most 
parts of which the scale was uniformly distributed. It con- 
tained 360 trees between eight and fifteen feet high. The varie- 
ties, with arrangement and treatment, are shown on Chart II. 
The pear and peach orchards joined the plums on the east. The 
pear orchard was very irregular, part being old and part recently 
set trees; all were sprayed as a precaution against possible infec- 
tion. The trees of the peach orchard which were slightly infested 
averaged about fifteen feet high. The arrangement and treat- 
ment of the latter is shown on Chart II. An apple orchard 
joined the plum orchard on the north; in this medium sized trees 
were twenty-five feet high. A few of the trees next the plum 
orchard were slightly infested. The varieties, their treatment 
and arrangement are shown on Chart IIT. 
In all five barrels of crude petroleum were used in these tests. 
The average specific gravity of the five barrels was 0.79 (44° on 
Baumé oil scale). 
. The winter treatments were made on December 7, 22 and 24. 
Clear, bright days with as little wind as possible were selected. 
The spring applications were made on April 12 and 13, under 
nearly the same conditions as those of December. 
