540 EXPERIMENT STATION RECORD. 



maldehyde gas, formaldehyde solution, and corrosive sublimate solution being 

 compared. 



It was found in laboratory experiments ttiat neither formaldehyde gas nor 

 solution can be depended upon to kill all the Rhizoctonia sclerotia. This seems 

 to be due to the inability of the formaldehyde to penetrate to the center of the 

 larger and more compact sclerotia. The standard corrosive sublimate treat- 

 ment, on the contrary, was found thoroughly efficient, and even when used in 

 a strength of 1 : 2,000 the corrosive sublimate solution killed all the Rhizoctonia 

 sclerotia. The author concludes that when it is desired to treat seed potatoes 

 for Rhizoctonia the corrosive sublimate should be used. 



The injurious effect of formaldehyde gas on potato tubers, F. C. Stewaet 

 and W. O. Gloyer (Xeio York State Sta. Bui. 369 (1913), pp. 385-416, pis. 2).— 

 In 1912 the authors undertook the disinfection of a quantity of seed potatoes 

 by the formalin-permanganate method, and as a result a great amount of 

 injury was caused. Investigations were subsequently inaugurated to deter- 

 mine the cause of the injury, temperature, relative humidity, quantity of po- 

 tatoes in proportion to space, and varietal differences being studied. It was 

 found that the chief cause of the injury was the small quantity of potatoes per 

 cubic foot of space in the fumigation chamber, although high relative humidity 

 and the sprouted condition of the potatoes were important accessories. 



Other experiments were carried on which have demonstrated the cause of 

 the injury and how to avoid it. It was found that potatoes absorb a consider- 

 able quantity of the gas, resulting in two forms of injury, one called lenticel 

 spotting and the other where the eyes are affected. In the experiments lenticel 

 spotting occurred with all quantities of tubers used up to 12 lbs. per cubic foot, 

 but no eye injury appeared when 5 lbs. or more per cubic foot were used. The 

 effect of the lenticel spotting on germination and growth has not been definitely 

 determined, but it is believed to be without material injury to the tubers for 

 seed purposes. 



In view of their experiments the authors recommend the use of gas treat- 

 ment only where liquid treatments are impracticable, and they recommend as 

 safe and efficient treatment for scab the use of 3 pints of formaldehyde and 23 

 oz. of permanganate of potash to 167 bu. of potatoes in 1,000 cu. ft. of space. 



In the course of the investigations it was found that similar injury to that 

 produced by formaldehyde gas was produced by fumes of ammonia, bromin, 

 or ether, and that strong solutions of formaldehyde and corrosive sublimate 

 had somewhat similar effects. In the use of formaldehyde solution the quan- 

 tity of potatoes treated had no appreciable influence on the degree of injury, 

 and it was found that the same solution may be used at least ten times without 

 loss of strength. 



Certain varieties of apples are also reported as being injured by formalde- 

 hyde gas. 



Some faults in formaldehyde disinfection of potatoes, F. H. Hall (New 

 York State Sta. Buls. 369 and 370, popular ed., pp. 10). — This is a popular 

 edition of the above bulletins. 



Diseases of rice, E. J. Butler (A^gr. Research Inst. Pusa Bui. 34 (1913), 

 pp. 37, pis. 3, figs. 3).— A further account (E. S. R., 28, p. 151) is given of 

 studies by the author on a disease of rice attributed to a nematode claimed to 

 be new and named Tylcnchus angustus, which is discussed at some length; 

 also some fungus diseases of rice, including bunt ascribed to Tilletia horrida, 

 false smut to Vstilaginoidea virens, and sterility to Sclerotium oryzw. 



The important cane fung-i in Santo Domingo, J. R. Johnston (Rpt. Bd. 

 Comrs. Agr. P. R., 2 (1912-13), pp. 29-31).— The author reports having found 

 the following important cane diseases in Santo Domingo ; Root disease, ascribed 



