AGRIC. 

 LIBRARY 



HANDBOOK OF THE DISEASES OF VEGETABLES 



OCCURRING UNDER MARKET, STORAGE 



AND TRANSIT CONDITIONS 



By GEORGE K. K. LINK and MAX W. GARDNER. Prepared under 

 the direction of W. A. ORTON and W. M. SCOTT. 1 



PREFACE 



This handbook is designed primarily to aid the inspectors 

 of the Bureau of Markets in the detection and identification 

 of plant diseases as they occur in vegetables under transit, 

 storage, and market conditions. 



The entire inspection service and the survey and study of 

 vegetable crop diseases under transit and market conditions, 

 were begun but little more than a year ago, consequently 

 this handbook, an outgrowth of that survey and study, is 

 necessarily incomplete. The text and illustrations are the 

 property of the United States Department of Agriculture, 

 and are not to be used in any published form whatsoever. 



The description of the signs, symptoms, or effects of each 

 plant disease is followed by a statement of the geographic 

 distribution and the seasonal or climatic relations of the 

 disease so far as they are known, since some diseases occur 

 only in certain districts and often only under certain con- 

 ditions. 



A statement is made as to the time and place of incep- 

 tion, development, and spread of the disease. This is 

 especially important from a market point of view. For 

 example, in placing the responsibility for the poor condition 

 of a shipment caused by bacteria or fungi, it is essential to 

 bear in mind that some diseases are field infections and do 

 not develop nor spread in transit or storage ; that others are 

 field infections which develop or progress but do not spread 

 ih transit or storage ; that others are field infections which 

 develop and spread under transit and storage conditions; 

 and finally that a number are transit and storage infections 

 of stock perfectly sound when harvested. 



It is fully realized that at present not all decay can be 

 referred to clearly defined causes. However, by specifying 

 whenever possible the disease responsible for the decay or 

 defect in a consignment, the inspector can further the con- 



1 Dr. V. B. Stewart was consulted freely in the preparation of the text. In addition, 

 the following men were consulted with reference to special portions as enumerated 

 below: Beans, Mr. W. W. Gilbert and Mr. G. A. Meckstroth; cabbage and other cruci- 

 fers, Dr. L. L. Barter and Dr. L. O. Kunkel; celery, Dr. I. C. Jagger; cucumber, Mr. 

 W. W. Gilbert and Mr. W. N. Ankeney; potato, Dr. H. A. Edson, Prof. L. R. Jones, 

 Dr. L. O. Kunkel, Dr. W. A. Orton, Mr. M. Shapovalov, Mr. E. S. Schultz, and Dr. 

 H. G. MacMillan; onion, Dr. J. C. Walker; lettuce, spinach, radish, etc., Dr. I. C. 

 Jagger, Mr. J. B. Norton and Mr. L. P. Byars ; tomato, Mr. G. H. Godfrey, Mr. F. J. 

 Pritchard, Dr. J. Rosenbaum and Mr. W. B. Clark; watermelon, Mr. F. C. Meier; sweet 

 potato, Dr. L. L. Harter and Dr. J. L. Weimer. 



922 



