328 
Journal of Agricultural Research 
Vol. XI, No. 7 
EFFECT ON THE COMPOSITION OF THE PLANT 
4 In view of the fact that the hydrocyanic acid absorbed by the plant 
is decomposed in the tissues, that the metabolism of the plant is changed 
because of the disturbed enzym equilibrium, and that several plants have 
been shown to utilize the nitrogen of the cyanid group (7, 14, 18), it 
was thought advisable to determine whether there was any change in 
the composition of tomato plants due to cyanid fumigation. 
Six uniform groups of 30 tomato plants were selected and fumigated 
in different ways, as described in Table II. After six weeks of growth they 
were cut off at the ground and the fresh weight, dry weight, percentage 
of ash, and percentage of protein determined for each set. From an 
examination of the data, it will be seen that there is no apparent change 
in the gross composition of these plants due to any combination of 
fumigation doses. 
Table II. —A nalysis of six sets of tomato plants fumigated with hydrocyanic acid , arranged 
in order of their total dry weight 
Set 
No. 
Treatment. 
Weight of 
plants. 
Ash. 
Protein. 
Fresh. 
Dry. 
Gm. 
Gm. 
Per cent. 
Per cent. 
XI 
i fumigation, 0.25 gm. of potassium cyanid 
per cubic meter overnight. 
1,463 
140 
21. 22 
14 - 31 
10 
3 fumigations, 0.25 gm. of potassium cyanid 
per cubic meter overnight, 2 weeks apart... 
r, 29s 
123 
16.45 
16. 84 
12 
1 fumigation, 1 gm. of potassium cyanid per 
cubic meter for 1.5 hours in daylight. 
1,174 
120 
19-95 
14. 28 
14 
1 fumigation, 0.5 gm. of potassium cyanid per 
cubic meter overnight. 
I, 089 
106 
20. 40 
14. 18 
IS 
Control, not fumigated. 
I, IOI 
103 
21. 88 
14-37 
13 
9 fumigations, 0.25 gm. of potassium cyanid 
per cubic meter overnight, 3 to 4 days apart.. 
944 
95 
21 . OO 
14. 28 
EFFECT ON THE GROWTH OF THE PLANT 
Townsend (20) has shown that there is an increase in germination in 
seeds fumigated with hydrocyanic acid. Woodworth (25) found that 
scale insect eggs fumigated with a sublethal dose of hydrocyanic acid 
resulted in their earlier hatching. Many of the fruit growers of the 
West are convinced that whether their trees are infested with insects 
or not they will not receive a maximum yield unless they have been 
given cyanid fumigation. A similar stimulation in the growth of plants 
may be noted in Table II, where four fumigated sets at the close of the 
fumigation exceeded in dry weight the normal set. In this experiment 
very frequent fumigation, with a consequent constant disturbance of 
photosynthetic activity, resulted in a diminished dry weight. 
