HTRKAU OF PLANT INDUSTRY. 211 



INSTRUCTION' OF FOOD-PRODUCTS INSPECTORS AND INVESTIGATIONS OF 

 DISEASES OF MARKET VEGETABLES. 



Cooperation has been continued with the Bureau of Markets in 

 the training of their fooJ-pro(hicts inspectors to recognize and in- 

 terpret vegetable diseases found in transit and in market. At train- 

 ing schools conducted at New York and Chicago about 20 new men 

 were instructed during the year, some of wdiom are still in the service 

 of the department, while others have entered State, corporation, or 

 private business, into which they carry their pathological training 

 and can thus act as a leavening influence for better production and 

 distribution of farm crops. This work has been followed by visits 

 to the various market headquarters and assistance given there 

 in the practical application of their knowledge. Requests from rail- 

 road claim agents, shippers, storage men, and others for information 

 concerning the disease problems connected with the production, 

 handlina% and storaire of vegetables became so numerous that the 

 preparation of a series of leaflets containing all the available in- 

 formation concerning the origin and spread of vegetable diseases 

 was begun. An important feature of the work has been the making 

 of observational trips to the [)roduoing centers, where first-hand in- 

 formation has been secured bearing on the development of diseases 

 in transit and in market. These inspection trips have brought to 

 light many new problems that need to be solved, as well as informa- 

 tion concerning the problems already under investigation. Our 

 pathologists have also responded to calls from the city health boards 

 for assistance in the training of their food inspectors. Progress has 

 been made in the study of carrot storage rots, a rot of cucumbers, and 

 a rot of cantaloupes and in a monographic study of the genus 

 Rhizopus, species of Avhich are associated with soft rots of many 

 vegetables. Additional data have been accumulated on the occur- 

 rence, distribution, and causes of diseases of market vegetables in 

 California, as well as the factors governing the development of these 

 diseases, particular attention having been given to tomato, lettuce, 

 cabbage, and cauliflower diseases. 



CONTROL OF THE WHITE-PINE BLISTER RUST. 



White-pine blister rust was first found attacking native pines in 

 Xorth America during the fall of 1015 in the States of Massachusetts 

 and New Hampshire. General scouting in 1916 showed that the dis- 

 ease was widespread in New England and northeastern New York. 

 Spot infections were discovered in Minnesota and Wisconsin, and a 

 few other States had one or more infected nurseries. This wide dis- 

 tribution caused the Federal (lovernment to establisli immediately 

 domestic quarantines to protect the five-needled pine forests of the 

 far West, and many States also enacted protective quarantine laws 

 and regulations. At this time the general eradication of Ribes (cur- 

 rants and gooseberries) was first tried as a practical method of 

 control in two local areas in Massafhusetts and one in New Hamp- 

 shire. 



Further scouting was carried on in the five-needled j:)ine regions 

 of the United States in 1017, and local demonstration control areas 



