68 VERMONT AGRICULTURAL REPORT. 



So tar as can be judged from the results of this single experiment 

 there is nothing to be gained by liming, there being but two per cent, 

 difference and that in favor of the untreated tubers. 



This trial of one season with only a few bushels of potatoes should 

 not be regarded as conclusive. It does, however, lead us to doubt the 

 value of the practice; yet the writer would be glad to learn of the ex- 

 perience of any potato growers with liming potatoes, where definite 

 gains were demonstrated. 



V. POTATO SCAB EXPERIMENT. 



Experiments in the disinfection of seed potatoes for scab were car- 

 ried out during the season of 1903, along the lines suggested by the 

 results of previous years. Two grades of seed were planted, "scabby" 

 and "smooth." 



The washed seed potatoes were divided into five lots; one was soaked 

 for two hours in formalin solution, 8 ounces in 15 gallons of water; 

 another was soaked for one and one-half hours in corrosive sublimate 

 solution, 1 ounce in 8 gallons of water; a third lot was moistened and 

 then submitted to the vapor of formaldehyde, a fourth was thus treated 

 dry, while a fifth lot was left entirely untreated. 



As in all previous trials, extending now through several years, cor- 

 rosive sublimate and formalin proved equally efficient. They afford a 

 cheap and eminently satisfactory means whereby the small potato 

 grower may combat scab. For the large grower and the seed dealer 

 who handles hundreds of bushels, a less laborious process is to be de- 

 sired. It would be so much more economical and satisfactory in such 

 cases to use a gaseous disinfectant that we have for several years been 

 testing various methods looking to this end. 



Formaldehyde gas is a most promising candidate for favor. Only one 

 per cent, of the crop raised from seed thus treated was scabby. 



We are not yet fully satisfied that this dry fumigation process is 

 equal to the disinfection attained by soaking the seed potatoes in for- 

 malin or in corrosive sublimate solution. These processes have been 

 proved reliable by long experience, where this fumigation method should 

 still be considered as in the experimental stage. In view of the several 

 years' results, however, and especially of those of the last summer, 

 dealers and large growers who do not consider the soaking process 

 practicable under their conditions, are advised to use the fumigation 

 process providing their storage room will permit it. 



