New Yoke Agricultural Experiment Station. 213 



SIMILAR INJURY PRODUCED BY OTHER GASES 



AND LIQUIDS. 



Tubers exposed to the fumes of ammonia, bromine or ether show- 

 depressed brown spots almost exactly like those resulting from 

 fumigation with formaldehyde gas. According to Orton and Field 

 a similar spotting may be pioduced by fumigation with sulphur. 40 

 In our experiments, dipping or soaking the tubers in strong solutions 

 of formaldehyde and corrosive sublimate has had the same effect. 

 In mild cases of injury only lenticel spotting occurred, while in 

 more severe ones there was also eye injury as with tubers injured 

 by treatment with formaldehyde gas. With the strengths commonly 

 used in treating potatoes for scab, viz., one pint of 40 per ct. for- 

 maldehyde to 30 gals, of water (1 to 240) and one ounce of corrosive 

 sublimate to 7 gals, water (1 to 1000, approximately), no spotting 

 of any kind has been observed by us or by any one else so far as 

 can be determined from the literature of the subject. Tubers 

 dipped in 37 per ct. formaldehyde and those which were soaked 

 two hours in 18 per ct. and 9 per ct. solutions showed both lenticel 

 spotting and eye injury. Solutions of from 2 to 9 per ct. strength 

 usually produced only lenticel spotting, although in one case some 

 eye injury resulted from the use of a 1| per ct. solution on sprouted 

 tubers. When the dilution was below one per ct. no spotting occurred. 



With corrosive sublimate some lenticel spotting occurred when 

 tubers were soaked one and one-half hours in solutions as weak 

 as 1 to 200. 41 In saturated solutions (1 to 16) and a 1 to 25 solution 

 there was both lenticel spotting and eye injury. 



FORMALDEHYDE GAS CAUSES SPOTTING AND 

 BROWNING OF APPLES. 



Some apples which were in the cellar at the time the original 

 case of injury occurred showed severe lenticel spotting — circular, 

 brown spots, 1 to 3 millimeters in diameter, surrounding the lenticels. 

 Similar spotting, also a browning of the skin, occurred subsequently 

 in several of our potato fumigation experiments in which a few 

 apples were introduced into the fumigation chamber. On Rome 



40 Orton, W. A., and Field, Ethel C. Sulphur injury to potato tubers. Science 



31:796. 20 My 1910. 

 41 One gram of corrosive sublimate dissolved in 200 cubic centimeters of distilled 



water. 



