270 Diseases of Economic Plants 



Experiment Station for 1889, and a comprehensive article 

 upon corn smut in the Twelfth Report of the Indiana Agricul- 

 tural Experiment Station. 



Present methods of seed treatment.^-^- ^-^ — Preliminary 

 to any form of seed treatment, the seed should be thoroughly 

 cleaned , in some cases floating-out of the spore-filled grains is 

 necessary, and after treatment it should be protected from 

 contamination. Sacks, bins, drills, etc., with which seed will 

 come in contact, should be disinfected with formalin. 



The common methods of cereal seed treatment now are by 

 formalin, hot water, or copper sulfate. The first is simpler and 

 easier and is preferable whenever it is effective. In treating 

 for certain kinds of smut, however, the formalin treatment is 

 not so effective as is the hot-water method. These three 

 methods with their limitations are as follows: 



The formalin wet method. — The seed to be treated is 

 either dipped in the solution of formalin, 1 pint to 30 or 

 40 gallons of water, or this solution is sprinkled on the seed, 

 with thorough mixing, at the rate of one gallon to each 

 bushel of seed. The pile is then blanketed and later spread 

 out to dry. 



In a modification known as the formalin dry method ^-^ the 

 seed is shoveled from one pile to another and each shovelful is 

 sprayed or sprinkled with a solution consisting of, formalin 

 (37 per cent formaldehyde) diluted with an equal amount 

 of water, and applied at the rate of one quart (1 pint of 

 formalin) to 50 bushels of seed. A quart sprayer is conven- 

 ient for use. After treating, the seed should be blanketed 

 for five hours, when it is ready for planting. Workmen 

 will find the formalin irritating to the mucous membrane, 

 and therefore should apply the solution as directly as possi- 

 ble to the seed. A variation from this method is to mix 1 

 pint of formalin with 10 or 12 gallons of water and sprinkle 

 on the seeds as they are shoveled over. They may then be 

 sacked immediately and sowed next day. This method, 

 employing a strong solution, seems to be both safe and 

 efficient with oats, but its use with wheat and other grains is 



