514 
Journal of Agricultural Research 
Vol. XXIV, No. 6 
Nevertheless, the investigator in this field must give it due recognition 
and repeat all work until a predominant tendency is clearly established. 
We have made it a point, therefore, in all cases in which certain results 
shown in a published table differed from those most commonly observed 
under the same conditions, to call attention to this fact. 
TabIvS IV .—Tomato plants in greenhouse, sprayed in triplicate, showing individual 
differences in susceptibility 
Chemical. 
Amoimt 
of chem 
icalin 2 
liters of 
water. 
Amoimt 
of soap 
in 2 
liters of 
water. 
Injury. 
Plant I. 
Plant 2. 
Plant 3. 
Lead arsenate, di- 
plumbic, Baker. 
Gm. 
9-4 
9-4 
9-4 
9-4 
Gm. 
0 
7.2 
14.4 
28.8 
None. 
.do. 
.do. 
None . 
.do . 
None. 
Do. 
Do. 
Moderate. 
Moderate . 
Moderate. 
Calcium arsenate, 
Merck. 
2.8 
2.8 
2.8 
. 2.8 
0 
7.2 
14.4 
28.8 
Very slight. 
Moderate. 
Slight. 
Moderate. 
Very slight. 
Slight. 
. do . 
Moderate . 
Very slight. 
Slight. 
Do. 
Moderate. 
Calcium arsenite, 
Adler. 
' 2.4 
2.4 
2.4 
. 2.4 
0 
7.2 
14.4 
28.8 
Moderate . 
Bad . 
Very bad . 
Partly defoli¬ 
ated. 
Moderate . 
Bad . 
Very bad . 
Partly d e f 0 1 i- 
ated. 
Moderate. 
Bad. 
Very bad. 
Partly defoli¬ 
ated. 
Calcium arsenite, 
Baker. 
■ 2.4 
2.4 
2.4 
. 2.4 
0 
7.2 
14.4 
28.8 
Moderate . 
Very bad . 
. do . 
. do . 
Moderate . 
Very bad . 
. do . 
Moderate. 
Very bad. 
Do. 
Do. 
Calcium arsenite, 
Merck. 
2.4 
2.4 
2.4 
. 2.4 
0 
7.2 
14.4 
28.8 
Slight. 
.do. 
Very slight. 
.do. 
Slight. 
Moderate . 
Very slight . 
Slight . 
Slight. 
Do. 
Very slight. 
Moderate. 
Arsenic trisul¬ 
phide, Baker. 
i 
0.8 
.8 
.8 
•8 
i 
0 
7.2 
14.4 
28.8 
None . 
Slight . 
Moderate. 
Very bad. 
Slight . 
Moderate . 
Very bad. 
Very slight. 
Moderate. 
Slight. 
Very bad. 
differences in parts of the plant 
In the spraying of trees and other plants all aerial portions are neces¬ 
sarily coated. This may or may not be necessary from the standpoint of 
controlling insects and diseases, but as it is practically unavoidable it 
makes the relative susceptibility of different parts of the plant to injury 
by the spray mixture of much importance in all spraying operations. 
This is especially true of fruit trees where,for example, the fruit may be 
russeted by Bordeaux mixture, greatly reducing its market value, while 
the same amount of burning on the leaves is unimportant. 
