276 ANN"UAL, REPORTS OF DEPARTME^TT OF AGRICULTURE. 



of a small percentage of these peas (Ban^alias) in the seed of the 

 Alaska variety, no matter how good it may be otherwise, absolutely 

 ruins the pack, because of the discoloration of the liquid in the cans. 

 High-grade seed true to varietal type is the only insurance against 

 such losses on the part of the grower as well as the canner. 



Pea diseases. — The investigations of the diseases of canning peas 

 have been continued and extended during the year, the principal 

 object being to find the cause and means of control of pea root-rot, 

 which causes greatly reduced yields in the older districts and is one 

 of the most serious pathological problems of this crop. It has been 

 found that the disease is not carried to any important extent in the 

 seed but is a soil infection which remains in the ground and in- 

 creases from year to year. A long crop rotation is the only method 

 of control known at present, and as the necessity for such rotations 

 reduces the returns in the intensive pea-growing districts better 

 means of control are being sought. Root-rot has been found to be 

 due mainly to four organisms {Aphanomyces sp., Pythium de- 

 haryanum^ Fusarium martii var. pisi^ and Rhizoctonia solani). 



DISEASE PROBLEMS IN TRANSIT AND MARKET. 



Cooperation with the Bureaii of Agricultural Economics in the 

 pathological phases of the work of food-products inspection has con- 

 tinued. This service has been expanded b}^ the inclusion of point-of- 

 origin inspection in cooperation with 19 States, for which additional 

 inspectors have been trained by our pathologists in the identification 

 of diseases causing transit losses in vegetables. This information has 

 also been given to the growers, shippers, carriers, and receivers of 

 market vegetables through illustrated lectures and a series of printed 

 circulars, of which seven have been prepared. The workers under 

 this project have also acted in an advisory capacity for the inspection 

 service of the Bureau of Agricultural Economics and assisted in 

 formulating those policies in which the plant-disease feature played 

 a role. Similar work is conducted in the handling and marketing 

 of fruits. 



Broccoli handling. — The investigations of the handling of broccoli 

 were carried on in the vicinity of Eoseburg, Oreg. The shippers 

 had been experiencing considerable difficulty in getting their product 

 to market in good condition. In many cases the leaves became yel- 

 low and dropped, the heads became riced and yellow, and the product 

 was rendered unattractive in other ways. The question as to whether 

 this breaking down was due to improper methods of transportation^ 

 to the way the product was harvested and handled, or to poor seed 

 was determined by a series of experiments carried out at Roseburg 

 last winter. In these experiments broccoli which was harvested at 

 different stages of maturity and handled in various ways was placed 

 in an iced refrigerator car on the siding at Roseburg and held 16 

 days. It was shown fairly conclusively that the troubles the shippers 

 were experiencing were due to the unsuitable varieties grown and the 

 improper methods of harvesting and handling. 



