INSECT ENEMIES AND DISEASES 
91 
138. “Sticker” or adhesive. — It is difficult to cause solu- 
tions or mixtures to adhere to the leaves of some plants; 
for example, the onion and cabbage. To obviate this 
trouble, a “sticker” may be made of 2 pounds of resin, 
1 pound of sal soda crystals and 1 gallon of water. This 
mixture is boiled out of doors from 1 to 1^ hours, or 
until the solution is of a clear brown color, and then 
added to every 50 gallons of bordeaux mixture and to 
every 100 gallons of other spray materials. 
Corrosive sublimate (bichloride of mercury) and for- 
maldehyde are used in the treatment of seeds for seed- 
borne diseases, such as potato scab, black leg of cab- 
bage, celery blight, and others. Irish potatoes are soaked 
for two hours in a solution of one pint of forty per cent 
formalin in 30 gallons of water, or, if the material is 
heated to 52 to 55 degrees Centigrade, the period of 
treatment may be reduced to 2^2 minutes, thus effect- 
ing a considerable saving of time, and securing better 
control of tuber diseases. Corrosive sublimate may be 
used for the same purpose at the rate of 4 ounces to 30 
gallons of water, for 1^2 hours. Seed sweet potatoes are 
treated for stem rot with corrosive sublimate at the same 
rate as given above, for 5 to 10 minutes. Small seeds 
as cabbage and celery are soaked in the bichloride of 
mercury solution only 10 minutes, then are washed with 
clear water and dried ; or 40 per cent formalin may be 
used at the rate of 1 teaspoonful to a pint of water for 
20 to 30 minutes. Corrosive sublimate is also used in 
the control of cabbage maggot as described in Chapter 
XXI. 
Various special methods for the control of insects and 
diseases will be discussed under Cultural Directions in 
Chapter XXI. 
