4 DEPARTMENT OF AGRICULTURE, BULLS. 76-100. 



Department Bulletin 80. — Effects of Varying Certain Cooking Con- 

 ditions in Producing Soda Pulp from Aspen — Continued. page. 



Effects of variations in the cooking conditions 15 



Influence of cooking conditions on cost 31 



Summary 38 



Practical value of results 40 



Appendix 41 



Aspen as a raw material for paper pulp 41 



Paper pulp from aspen 44 



Records of the series tests 47 



Methods for auxiliary tests 54 



Autoclave tests on aspen 57 



Bibliography 61 



Department Bulletin 81. — The Potato Quarantine and the American 

 Potato Industry: 



Introduction 1 



Review of the potato-disease situation 2 



Introduced parasites the more dangerous 2 



The wart disease 4 



Powdery scab 5 



Other reasons for potato regulations 10 



A general quarantine now in effect 12 



General explanation of regulations 13 



Relation of imported to domestic potatoes 15 



The 1913 potato crop 16 



A progressive policy needed '. 17 



Protection from disease 18 



Lack of an outlet for surplus potatoes 19 



Department Bulletin 82. — Powdery Scab (Spongospora Subterranea) 

 of Potatoes: 



Introduction 1 



Common name of the disease caused by spongospora 2 



Scientific name of powdery scab 2 



Description of the disease 3 



Geographical distribution of powdery scab 5 



Presence of powdery scab in Canada 6 



Powdery scab in the United States 6 



Damage to the potato crop 7 



Effect on seed potatoes 7 



Is powdery scab a dangerous malady? 8 



Macroscopic differences between spongospora and oospora scab 10 



Function of the spore balls and methods of infection 11 



Seed treatment 12 



Soil treatment 12 



Sacks and barrels as agents in spreading powdery scab 14 



Bibliography 15 



Department Bulletin 83. — Farmers' Institute and Agricultural Ex- 

 tension Work in the United States in 1913: 



Progress of farmers' institutes in 1913 1 



Growth of the institutes during the last decade 3 



Administrative methods 4 



Association of farmers' institute workers 7 



Extension work by the agricultural colleges 8 



Section on extension work of the association of American agricultural 



colleges and experiment stations 10 



