2i6 Maine; agricuIvTural i^xperim^nt station. 1911. 



Seed tubers untreated. Diseased plants per acre 390 



Seed tubers treated (formaldehyde gas). 



Diseased plants per acre ' 150 



While there was a considerable number of diseased hills on 

 the treated portion of the field the fact should not be overlooked 

 that over 60 percent of the disease as compared with the plants 

 grown from the untreated seed was eliminated by the treat- 

 ment. As is stated elsewhere in this paper while the large 

 amount of blackleg on the treated seed, compared with the 

 results obtained in the Parsons, Donaldson and Hussey experi- 

 ments, may indicate that the gas treatment is less effective than 

 the liquid treatment. It should be noted that in these last men- 

 tioned experiments the owners were able to either cut the seed 

 themselves or have it do'ne under their immediate supervision. 



The Blake Bxperinient. 



Mr. Blake treated sufficient selected seed to plant about 20' 

 acres of Irish Cobblers. About half of this was soaked iil 

 formaldehyde solution and the remainder given the gas treat- 

 ment in the Edblad disinfecting room. Unfortunately no un- 

 treated check plot was planted at the same time with the same 

 lot of seed. Such a plot was planted some 10 days or 2 weeks 

 later and there was also some doubt as to whether the seed was 

 from the same source as that originally planted. Obviously 

 this could not be used as a check on the treated portion. The 

 field was carefully examined first on July 7 and again on July 

 20 as it represented the only case where the liquid and gas 

 methods of treatment were applied to seed on the same field. 

 No' comparisons between these could be made, however, for 

 only two plants showing the disease could be found on the 

 whole 20 acres. This disease was said to have been observed 

 on the crop of the year before from which the seed was ob- 

 ta'ned, therefore it would seem that its absence the present 

 season must be the result of seed selection, disinfection or both. 



The Bdhlad B.vperiment. 



Mr. Edblad disinfected all of his seed by the formaldehyde 

 gas method except about i barrel of the Irish Cobblers which 

 was not treated, and planted the following varieties: Green 



