UNITED STATES DEPARTMENT OF AGRICULTURE 





rontribution from the Bureau of Plant Industry 

 WM. A. TAYLOR, Chief. 



J\J^"^^U 



Washington, D. C. 



PROFESSIONAL PAPER 



August 19, 1922 



THE CONTROL OF SAP-STAIN, MOLD, AND INCIP- 

 IENT DECAY IN GREEN WOOD, WITH SPECIAL 

 REFERENCE TO VEHICLE STOCK/ 



By Nathaniel O. Howard, Pathologist, Office of Investigations in Forest 



Pathology. 



(In cooperation with tlie Forest Products Laboratory of the United States Forest Sery- 



ice, Madison, Wis.) 



CONTENTS. 



Page. 



Introduction 1 



Sap-stain 3 



Other fungous organisms causing 

 surface discolorations in green tim- 

 ber 12 



Factors which favor the growth of 



sap-stain and mold fungi 14 



Page. 



Durability of stained or molded 



wood 17 



Losses due to sap-stain or mold 18 



Control measures 21 



Summary 50 



Literature cited 52 



INTRODUCTION. 



During periods of transit and storage, previous to its ultimate 

 manufacture, green timber containing a high percentage of sapwood 

 often suffers considerable damage. This is particularly true during 

 the late spring and summer months when deterioration brought about 

 mainly through a discoloration of the sapwood, known as sap-stain, 

 sometimes necessitates degrading on a large scale. This staining 

 of timber has occasioned severe losses in Europe as well as in the 

 United States, and many expensive investigations have been made to 

 determine the nature of the stain and to discover a satisfactory 

 remedy. 



1 The writer wishes to acknowledge his indebtedness to Mr. C. J. Humphrey, in charge 

 of the Laboratory of Forest Pathology, Bureau of Plant Industry, in cooperation with 

 the Forest Products Laboratory, Madison, Wis., for facilities and for advice in Outlining 

 the work ; to Dr. Charles Thom and Miss Margaret B. Church, of the Bureau of Chem- 

 istry, for the identification of mold fungi ; to Mr. H. D. Tiemann, physicist and specialist 

 in kiln drying, Forest Products Laboratory, Madison, Wis., for the loan of photographs ; 

 to Mr. Joseph Ashcroft, of Poplar Bluff, Mo., for cooperation in the experimental dipping 

 of spokes ; and to all others who, by information, suggestion, or criticism, have con- 

 tributed to the preparation of the manuscript of this bulletin. 

 75579°— 22 1 



