3 IQ 
Journal of Agricultural Research 
Vol. VIII, No. 8 
When trees are wounded at the crown, as by the cutting off of water 
sprouts, which is a fairly common orchard practice, the danger of arsen¬ 
ical injury is greatly increased, as shown by a comparison of the wounded 
and unwounded trees in this table. 
To determine whether a more rapid injury could be produced by larger 
applications of more injurious chemicals, the tests were made that are 
recorded in Table X. A study of this table leaves no doubt that the 
crown of an apple tree is very poorly protected against the absorption of 
arsenicals. Three days after treatment nearly every tree showed some 
symptoms in the foliage and at the end of a week every tree was badly 
injured. In a few weeks every crown was completely girdled. 
Table "K.-^Results of treating unwounded crowns of apple trees on July ig , JQi2 t with 
500 gm. of Baker*s calcium arsenite , to determine the extent and character of injury 
No. 
Diame¬ 
ter of 
trunk. 
Injury 1 week after treat- 
ment. 
Injury 9 weeks after treatment. 
Injury 8% months after 
. treatment. 
Inches. 
x 
2 
3 
4 
5 
6 
3 
3 
3K 
3 K 
6 
9 
No injury except the killing 
of water sprout at base of 
tree. 
Streak runs up trunk on 
north side and out onto 
several limbs. More than 
half the leaves, especially 
on north side, badly in¬ 
jured. 
Faint streaks rim from trunk 
onto several limbs. About 
two-thirds the leaves, espe¬ 
cially on southeast side, 
badly injured.® 
Leaves of four spurs on main 
limb badly injured. • 
Faint streaks run from trunk 
onto limbs. About one- 
fourth the leaves injured. 
Many leaves badly injured.. 
Crown girdled. No streaking. 
Foliage strongly purplish in 
color. 
Crown girdled. One wide streak 
and one narrow one run to top 
of tree. About one-third the 
leaves killed and others spot¬ 
ted . The rest have a strongly 
purplish color. Fruit small 
and highly colored, except on 
killed limbs, where it is dead 
and shriveled. 
Crown girdled. Streak three- 
fourths around trunk runs to 
top of tree. About three- 
fourths the leaves killed and 
others spotted. The rest nor¬ 
mal in color. 
Crown girdled. Wide streak 
runs to top of tree. About 
one-fourth the leaves killed or 
spotted. The rest normal in 
color. 
Crown girdled. One wide and 
one narrow streak run to top of 
tree. About one-eighth the 
leaves killed or spotted, the 
rest purplish in color. 
Girdled at crown and for 18 
inches above ground. Several 
streaks run to top of tree. 
About one-half the leaves dead 
and many others spotted, the 
rest normal in color. Fruit 
dark and soft at core. 
Bark around crown be¬ 
low ground very dark 
and friable. 
Bark at crown not so 
dark as No. 1 and 
rather tough instead 
of friable. 
Bark at crown rather 
dark and more friable 
than after 9 weeks. 
About like No. 3. 
Bark at crown very dark 
and friable. 
Do. 
® In removing the soil from crown for treatment a slight wound, not through the bark, was accidentally 
made on west side. 
Of much significance in reference to the interpretation of these results 
(see p. 314) is the change that takes place under ground. On Septem¬ 
ber 26, nine weeks after treatment, the color of the dead bark below 
and above ground was about the same—namely, about the same shade 
of brown as a roasted coffee berry. By the following March the color 
below the ground was a very much darker brown, especially that of No. 
