CONTENTS. 



Department Bulletin No. 513. — Fumigation op Ornamental Greenhouse 



Plants with Hydrocyanic-acid Gas: Page. 



Introduction _. 1 



Equipment necessary for fumigation 2 



Preparation of houjse for fumigation 3 



Method of computing the cubical contents of even and three-quarter-span 



greenhouses 4 



Time for fumigation 4 



Chemicals required for fumigation 5 



Determining the amount of cyanid to be used ; . . 5 



Chemical formula to be employed 6 



Mixing the chemicals 7 



Number of generators to be employed 7 



Exposures 7 



Ventilation after fumigation • 8 



Effects of weather conditions on fumigation 8 



Advisability of a fumigation box 9 



How insects are disseminated from house to house 9 



Cost of hydrocyanic -acid gas fumigation 10 



Precautions 11 



Plants and insects fumigated in greenhouses 11 



Plants and insects fumigated in fumigation box 18 



Conclusions 20 



Department Bulletin No. 514. — Wheat, Yields Per Acre and Prices, by 

 States, 50 Years, 1866-1915: 



Iittroduction 1 



Wheat, yields per acre and prices by States 2 



Department Bulletin No. 515. — Corn, Yields Per Acre and Prices, by 

 States, 50 Years, 1866-1915: 



Introduction 1 



Corn, yields per acre and prices by States 2 



Department Bulletin No. 516. — Table for Converting Weights of 

 Mechanical Separations into Percentages of the Sample Analyzed: 



Introduction 1 



Directions for using the table 2 



Department Bulletin No. 517. — An Intradermal Test for Bacterium 

 Pullorum Infection in Fowls: 



Dissemination of infection in white diarrhea 1 



The agglutination test 2 



Experimental work. 2 



Comparison of results of agglutination and intradermal tests 12 



Significance of swelling as an indication of reaction 13 



Various biologic tests 14 



Summary and conclusions 14 



Department Bulletin No. 518. — The Cost of Producing Apples in Hood 

 ,E,iVER Valley: 



' Facts brought out 2 



Conclusions 4 



The Hood River Valley 5 



Farm organization 12 



The orchards 15 



Marketing and prices received 17 



Orchard management 18 



Maintenance labor 19 



Handling crop 40 



Total labor costs 47 



Costs other than labor 48 



Total costs 50 



Department Bulletin No. 519. — Poles Purchased, 1915: 



Introduction 1 



Preservation 4 



